阅读说明：本技术 用于使用剪切辅助加工和挤压形成中空轮廓非圆形挤压件的方法 (Method for forming hollow profile non-circular extrusions using shear assisted machining and extrusion ) 是由 维尼特·V·乔希 斯科特·A·华伦 柯特·A·拉维达 格伦·J·格兰特 马里兰·丽沙·E·拉 于 2019-07-05 设计创作，主要内容包括：公开了使用具有涡旋面的装置形成挤压产品的工艺,该涡旋面被构造成向材料上的相同预选位置施加旋转剪切力和轴向挤压力,其中在相同位置上的旋转剪切力和轴向挤压力的组合导致材料的一部分塑化、流动和以期望的构型重新组合。这个工艺提供了大量的优点和工业应用(包括但不限于用于车辆部件的挤压管),与常规挤压技术相比具有大50％至100％的延展性和能量吸收,同时显著降低了制造成本。(A process is disclosed for forming an extruded product using an apparatus having a scroll face configured to apply a rotational shear force and an axial compressive force to the same preselected location on a material, wherein the combination of the rotational shear force and the axial compressive force at the same location results in a portion of the material plasticizing, flowing, and recombining in a desired configuration. This process provides numerous advantages and industrial applications (including but not limited to extruded tubes for vehicle components) with 50% to 100% greater ductility and energy absorption compared to conventional extrusion techniques, while significantly reducing manufacturing costs.)

1. A shear-assisted extrusion method for forming a non-circular hollow profile extrusion of a desired composition from a feedstock material, the method comprising the steps of:

simultaneously applying an orbiting shear force and an axial compression force to the same location on the stock material using a scroll having a scroll face with a plurality of grooves defined therein configured to direct plasticized material from a first location to a second location through an inlet defined in the scroll face.

2. The method of claim 1, wherein the scroll member has a plurality of inlets, each inlet configured to direct plasticized material through the scroll face.

3. The method of claim 2, wherein the grooves on the scroll face include a first set of grooves configured to direct plasticized material in a first direction and a second set of grooves configured to direct plasticized material in a second direction.

4. The method of claim 3 wherein the extruding of the plasticized material is performed at a die face temperature of less than 150 ℃.

5. A method according to claim 3, wherein said axial compression force is equal to 50MPa or below 50 MPa.

6. The method of claim 3, wherein the material is in powder form.

7. A method according to claim 3, wherein said material is a magnesium alloy in billet form, said axial compression force being equal to or below 25MPa and the temperature being lower than 100 ℃.

8. An apparatus for performing shear assisted extrusion, comprising:

a scroll face configured to apply a rotational shear force and an axial compression force to the same preselected location on the material, wherein a combination of the rotational shear force and the axial compression force at the same location causes a portion of the material to plasticize, the scroll face further comprising at least one groove and an inlet defined in the scroll face, the groove configured to direct a flow of plasticized material through the inlet to a second location, wherein the plasticized material rejoins after passing through the scroll face to form an extruded material having preselected characteristics.

9. A shear assisted extrusion process for producing high entropy alloys; the method comprises the following steps:

positioning a preselected high entropy material in contact with a rotating vortex surface within a shear assisted extrusion device; and

while exerting rotational and axial forces on the material sufficient to cause plasticization and mixing of the material and the high entropy alloy material at the interface of the vortex faces.

10. The method of claim 9, wherein the orbiting scroll face has at least two starts.

11. The method of claim 10, wherein the rotating scroll face rotates at a speed of 10 to 1000 revolutions per minute.

12. The method of claim 10, wherein the rotational shear force is less than 50 MPa.

Background

The increasing demand for fuel efficiency in transportation coupled with the ever increasing demand for safety and compliance has led to a focus on the development and utilization of new materials and processes. In many cases, the barriers to entry into these areas are due to the lack of efficient and effective manufacturing methods. For example, the ability to replace steel automotive parts with materials made of magnesium or aluminum or their associated alloys is of great interest. Additionally, the ability to form hollow parts having a strength equal to or greater than solid parts is an additional desired objective. Previous attempts have failed or been limited by various factors including the lack of suitable manufacturing processes, the expense of using rare earths in alloys to impart desired properties, and the high energy cost of production.

What is needed is a process and apparatus that can produce such parts in an automotive or aerospace vehicle having a hollow cross-section, made of materials with or without rare earths, such as magnesium or aluminum metal. What is also needed is a process and system for producing such articles that is more energy efficient, can be more easily implemented, and produces materials having a desired grain size, structure, and arrangement in order to maintain strength and provide adequate corrosion resistance. There is also a need for a simplified process that can form such structures directly from a billet, powder or flake material without the need for additional processing steps. There is also a need for new methods for forming high entropy alloy materials that are simpler, more efficient and simplified than current processes. The present disclosure provides a description of significant advances in meeting these needs.

Over the past few years, researchers in the western pacific national laboratories have developed a novel Shear Assisted Processing and Extrusion (Shear ape) technique that uses rotary stampings or dies rather than the simple axial feed stampings or dies used in conventional Extrusion processes. As described hereinafter and in the previously cited, referenced and incorporated patent applications, this process and its associated apparatus provide a number of significant advantages, including reduced power consumption, better results, and the realization of a new set of "solid phase" type forming processes and machines. The deployment of the advantages of these processes and devices is envisioned in a variety of industries and applications, including but not limited to transportation, ballistic, high temperature applications, structural applications, nuclear applications, and corrosion resistant applications.

Various additional advantages and novel features of the invention are described herein, and will become more apparent to those skilled in the art from the following detailed description. In the foregoing and following description, we have shown and described only the preferred embodiments of this invention by way of illustration of the best mode contemplated for carrying out this invention. It will be understood that the invention is capable of modification in various respects, all without departing from the invention. Accordingly, the drawings and description of the preferred embodiments set forth below are to be regarded as illustrative in nature, and not as restrictive.

Disclosure of Invention

The present specification provides examples of a shear-assisted extrusion process for forming a non-circular hollow profile extrusion of a desired composition from a feedstock material. This is achieved at a high level by simultaneously applying a rotational shear force and an axial pressing force to the same position on the raw material using a scroll face having a plurality of grooves defined therein. These grooves are configured to direct plasticized material from a first location (typically at the interface between the material and the scroll face) through an inlet defined in the scroll face to a second location (typically on the mold support surface). In this position, the separate streams of plasticized material are recombined and reconfigured into a desired shape having preselected characteristics.

In some applications, the scroll face has a plurality of inlets, each configured to direct plasticized material through the scroll face and recombine, either uniformly or separately, at a desired location. In the particular application described, the scroll face has two sets of grooves, one set for directing material from the outside and the other set configured to direct material from the inside. In some cases, a third set of grooves surrounds the scroll face to contain material and prevent flash.

This process provides a number of advantages, including the ability to form materials with better strength and corrosion resistance properties at lower temperatures and with lower forces, and with much lower energy intensity than required by other processes.

For example, extrusion of the plasticized material is carried out at a die face temperature of less than 150 ℃. In other cases, the axial compressive force is equal to or lower than 50 MPa. In one particular example, a magnesium alloy in billet form is extruded into a desired form in an arrangement in which the axial extrusion force is equal to or less than 25Mpa and the temperature is less than 100 ℃. While these examples are provided for illustrative reasons, it should be clearly understood that the present description also contemplates various alternative configurations and alternative embodiments.

Another advantage of the presently disclosed embodiments is the ability to produce high quality extruded material from a variety of raw materials, including billets, flakes, powders, etc., without the need for additional pre-or post-processing to achieve the desired results. In addition to this process, this specification also provides an exemplary description of an apparatus for performing shear assisted extrusion. In one configuration, this device has a vortex surface configured to apply a rotational shear force and an axial compressive force to the same preselected location on the material, wherein the combination of the rotational shear force and the axial compressive force at the same location results in a portion of the material being plasticized. The scroll face also has at least one groove and an inlet defined in the scroll face. The grooves are configured to direct a flow of plasticized material from a first location (typically on the face of the vortex) through the inlet to a second location (typically on the back side of the vortex and at some location along the mandrel having the die bearing surface). Wherein the plasticized material rejoins after passing through the vortex surfaces to form an extruded material having preselected characteristics at or near these second locations.

This process offers a number of advantages and industrial applications. For example, this technique enables extrusion of wires, rods and tubes for vehicle components with 50% to 100% greater ductility and energy absorption than conventional extrusion techniques, while significantly reducing manufacturing costs. This is done on a smaller, less expensive machine than that used in conventional extrusion equipment. In addition, this process produces extrusions from lightweight materials (such as magnesium and aluminum alloys) with improved mechanical properties not achievable using conventional extrusion and can be produced directly from powders, flakes or billets in a single step, which greatly reduces overall energy consumption and process time compared to conventional extrusion.

The application of the method and apparatus may be, for example, for forming a part for the front end of an automobile, where it is expected that a weight savings of 30% may be achieved by replacing aluminum components with lighter weight magnesium, and a weight savings of 75% may be achieved by replacing steel with magnesium. Typically, processing into such embodiments requires the use of rare earth elements in the magnesium alloy. However, these rare earth elements are expensive and rare, and are found in environmentally difficult areas in many cases. Magnesium extrusions are too expensive for all but the most exotic vehicles. Thus, less than 1% of the weight of a typical passenger car comes from magnesium. However, the process and apparatus described below enable the use of non-rare earth magnesium alloys to achieve results comparable to those using rare earth materials. This results in additional cost savings in addition to a ten-fold reduction in power consumption (due to the much less force required to produce the extrusion) and smaller machine footprint requirements.

Therefore, the present technology can be easily adapted to manufacture lightweight magnesium parts for automobiles, such as front-end bumper beams and crush cans. In addition to automobiles, the deployment of the present invention can drive further innovation and development in various industries such as aerospace, electrical power industry, semiconductors, and the like. This technique can be used, for example, to produce creep resistant steel for heat exchangers in the electrical power industry, as well as advanced magnets and high conductivity copper for electrical machines. It is also used for the production of high strength aluminium bars for the aerospace industry, where the aluminium bars are extruded directly from powder in one single step, with twice the ductility compared to conventional extrusion. In addition, the solid state cooling industry is investigating the use of these methods to produce semiconductor thermoelectric materials.

The method of the present invention allows for precise control of various characteristics, such as grain size and crystallographic orientation, which determine the mechanical properties (e.g., strength, ductility, and energy absorption) of the extrusion. This technique produces grain sizes of magnesium and aluminum alloys in the ultra-fine range (< 1 micron), which represents a 10 to 100 fold reduction compared to the raw material. In magnesium, the crystal orientation may be aligned away from the extrusion direction, which is why the material has such a high energy absorption. A 45 degree offset has been achieved which is ideal for maximizing energy absorption in magnesium alloys. Control of grain refinement and crystal orientation is obtained by adjusting the geometry of the helical groove, the rotational speed of the die, the amount of frictional heat generated at the material-die interface, and the amount of force used to push the material through the die.

Furthermore, such an extrusion process allows for the production of materials with tailored structural properties on an industrial scale. Unlike severe plastic deformation techniques that are only capable of laboratory scale production, the ShAPE can be scaled according to industrial productivity, length, and geometry. In addition to controlling grain size, another layer of microstructure control has been demonstrated, where grain size and texture can be tuned by the wall thickness of the pipe — this is important because mechanical properties can now be optimized for extrusion depending on whether the end application is to be subjected to tension, compression or hydrostatic pressure. This may allow the automotive component to better resist failure during a collision while using less material.

This process combines linear and rotary shearing, resulting in a reduction of the extrusion force by a factor of 10 to 50 compared to conventional extrusion. This means that the size of the hydraulic rams, support members, mechanical structures and overall footprint can be greatly reduced compared to conventional extrusion equipment-thereby enabling much smaller production machinery, reducing capital expenditure and operating costs. This process generates all of the heat required to produce the extrusion by friction at the interface between the system blank and the scroll face die, thus eliminating the need for pre-heating and external heating used by other methods. This results in a greatly reduced power consumption; for example, 11kW of power is required to produce a 2 inch diameter magnesium tube as much as the electrical power to operate a domestic kitchen oven — a reduction in power consumption of 10 to 20 times compared to conventional extrusion. Extrusion ratios as high as 200: 1 are demonstrated for magnesium alloys using the described method compared to 50: 1 for conventional extrusion, which means that less or no material repetition through the machine is required to achieve the final extrusion diameter-resulting in lower production costs compared to conventional extrusion.

Finally, studies have shown a 10-fold reduction in corrosion rate for extruded non-rare earth ZK60 magnesium conducted under this process compared to conventional extruded ZK 60. This is due to the highly refined grain size and the ability to break down, uniformly distribute (even dissolve) the second phase particles (which typically act as corrosion initiation sites). The process is also used to clad magnesium extrusions with an aluminum coating to reduce corrosion.

Various advantages and novel features of the disclosure are described herein, and will become more apparent to those skilled in the art from the following detailed description. In the foregoing and following description, exemplary embodiments of the present disclosure are provided through an illustration of the best mode for practicing the present disclosure. It will be understood that the present disclosure is capable of modification in various respects, all without departing from the present disclosure. Accordingly, the drawings and description of the preferred embodiments set forth below are to be regarded as illustrative in nature, and not as restrictive.

Drawings

Figure 1a shows a ShAPE setup for extruding a hollow section.

Fig. 1b shows another configuration for extruding a hollow section.

FIG. 2a shows a top perspective view of an improved scroll tool for an inlet bridge die.

Figure 2b shows a bottom perspective view of the modified scroll face operating as an inlet bridging die.

Figure 2c shows a side view of the improved inlet bridging die.

Fig. 3 shows a schematic view of the apparatus and process for material separation shown in fig. 1-2.

Fig. 4a shows a ShAPE setup for consolidating High Entropy Alloy (HEA) from an arc melting disk (puck) into a dense disk.

Fig. 4b shows an example of a vortex surface of the rotary tool in fig. 4 a.

Figure 4c shows an example where the HEA arc melted sample was crushed and placed within the chamber of the shepe apparatus prior to processing.

FIG. 5 shows a BSE-SEM image of a cross-section of a HEA arc melted sample prior to ShAPE treatment, showing porosity, intermetallic phase and nucleated dendritic microstructure.

Fig. 6a shows a BSE-SEM image at the bottom of the disk resulting from the processing of the material in fig. 4 c.

Figure 6b shows a BSE-SEM image of the middle of the disk.

Figure 6c shows a BSE-SEM image of the interface between the high shear region and the non-uniform region (about 0.3mm from the disc surface).

FIG. 6d shows a BSE-SEM image of the high shear region.

Detailed Description

The following description, including the figures, provides various examples of the invention. It will be clear from the description of the invention that the invention is not limited to these illustrated embodiments, but that the invention also comprises various modifications and embodiments thereof. The description is thus to be regarded as illustrative instead of limiting. While the invention is susceptible to various modifications and alternative constructions, it should be understood that it is not intended to limit the invention to the particular forms disclosed, but on the contrary, the intention is to cover all modifications, alternative constructions, and equivalents falling within the spirit and scope of the invention as defined by the appended claims.

In the previously described and related applications, various methods and techniques are described, wherein the described techniques and apparatus (referred to as ShAPE) are shown to provide a number of significant advantages, including the ability to control microstructure (such as crystallographic texture) through cross-sectional thickness, while also providing the ability to perform various other tasks. In this specification we provide information on the formation of materials with non-circular hollow profiles using the ShAPE technique, and methods for manufacturing high entropy alloys, which are useful in various applications (e.g. projectiles). Exemplary applications are discussed in more detail below.

Referring now first to fig. 1a and 1b, examples of a shepe device and arrangement are provided. In an arrangement such as that in fig. 1, the rotary die 10 is pushed into the material 20 under certain conditions whereby the rotational and shear forces of the die face 12 and the die plunger 16 combine to plasticize the material 20 at the interface of the die face 12 and the material 20 and cause the plasticized material to flow in a desired direction. (in other embodiments, the material 20 may be rotated and the mold 10 pushed axially into the material 20 to provide this combination of forces at the material face). In either case, the combination of the axial and rotational forces plasticizes the material 20 at the interface with the die face 12. The flow of plasticized material may then be directed to another location where a preselected length of the mold support surface 24 facilitates the recombination of the plasticized material into an arrangement in which new and better grain size and texture control at the microscopic level may be performed. This is then converted into an extruded product 22 having the desired characteristics. This process achieves better strength and corrosion resistance, as well as higher and better performance on a macroscopic level. This process eliminates the need for additional heating and curing and enables the process to function with materials in various forms, including billets, powders or flakes, without requiring extensive preparation processes (such as "steel canning"). This arrangement also provides a method for performing other steps such as cladding, enhanced control of through wall thickness and other properties.

This arrangement is different from and provides various advantages over prior art methods for extrusion. First, during extrusion, the force peaks at the beginning and then drops once extrusion begins. This is called breakthrough progression. The temperature at the point of breakthrough progression during this ShAPE process is very low. For example, for magnesium tubes, the temperature at which ZK60 tube breakthrough development with an OD of 2 "and a wall thickness of 75 mils progressed was less than < 150 ℃. This lower temperature breakthrough progression is believed to be partly responsible for the superior construction and performance of the resulting extruded products.

Another feature is a low squeeze coefficient kf, which describes squeeze resistance (i.e., lower kf means lower squeeze force/pressure). Kf was calculated to be 2.55MPa and 2.43MPa for extrusions (2 "OD, 75mil wall thickness) made from ZK60-T5 bar and ZK60 castings, respectively. The impact force and kf are very low compared to conventional extruded magnesium, where kf is between 68.9 and 137.9 MPa. Thus, the ShAPE process achieves a 20 to 50-fold kf (and thus ram pressure) as compared to conventional extrusion. This not only contributes to the properties of the resulting material, but also reduces the energy consumption required for manufacture. For example, in this process, 11.5kW of electrical power is required to extrude ZK60-T5 rods and ZK60 castings (2 "OD, 750mil wall thickness). This is much lower than conventional methods using heated containers/blanks.

The ShAPE process is significantly different from Friction Stir Back Extrusion (FSBE). In FSBE, a rotating mandrel is punched into the contained blank, much like a drilling operation. The swirl grooves push the material outward and the material is back extruded around the mandrel to form a tube, rather than being pushed through a die. As a result, only very small extrusion ratios are possible, the tube is not fully processed through the wall thickness, the extrudate cannot be ejected from the mandrel, and the tube length is limited by the length of the mandrel. In contrast, ShAPE utilizes helical grooves on the die face to feed material inwardly through the die and around a mandrel that travels in the same direction as the extrudate. Thereby, larger outer diameters and extrusion ratios are possible, the material is processed uniformly through the wall thickness, the extrudate can be pushed freely off the mandrel as in conventional extrusion, and the extrudate length is limited only by the starting volume of the billet.

An example of an arrangement using the ShAPE device and mandrel 18 is shown in FIG. 1 b. Such devices and associated processes have the potential to be low cost manufacturing techniques for producing a variety of materials. As will be described in greater detail below, in addition to modifying various parameters of the process, such as feed rate, heat, pressure, and rotation rate, various mechanical elements of the tool help achieve various desired results. For example, a varying swirl pattern 14 on the face of the extrusion die 12 may be used to affect/control various characteristics of the resulting material. This may include controlling the grain size and crystallographic texture along the length of the extrusion as well as the through-wall thickness and other characteristics of the extruded tubing. Changes in parameters can be used to advantageously alter bulk material properties such as ductility and strength, and allow tailoring for specific engineering applications, including changing crush resistance, pressure, or bending.

The ShAPE process has been used to form various structures from various materials, including the arrangements described in the following table.

TABLE 1

In addition to the disks, rods and tubes described above, the present disclosure also provides a description of the use of a specially configured scroll member, referred to by the inventors as an inlet bridging die, that allows the manufacture of a ShAPE extrusion having a non-circular hollow profile. This configuration allows the use of specially formed entry bridging dies and associated tooling to produce extrusions having non-circular and multi-zone hollow profiles.

Fig. 2 a-2 c show various views of an inlet bridging die design with a modified scroll face that is unique to operation in the shear process. Fig. 2a shows an isometric view of the vortex face on top of the inlet bridge die and fig. 2b shows an isometric view of the bottom of the inlet bridge die with the mandrel visible.

In this embodiment, the grooves 13, 15 on the face 12 of the die 10 direct the plasticized material toward the orifice 17. The plasticized material then passes through the orifice 12 where it is directed to a die support surface 24 within the weld chamber similar to conventional inlet bridge die extrusion. In this illustrative example, four ports 17 are used to divide the material flow into four different flows as the blank and die are pushed against each other as they rotate.

As the outer grooves 15 on the die face feed material inwardly toward the ports 17, the inner grooves 13 on the die face feed material radially outwardly toward the ports 17. In this illustrative example, for a total of four outwardly flowing grooves, one groove 13 feeds material radially outward toward each port 17. The outer groove 15 on the die surface 12 feeds the material radially inward toward the port 17. In this illustrative example, for a total of eight inward feed grooves 15, two grooves feed material radially inward toward each port 17. In addition to these two sets of grooves, the peripheral grooves 19 on the outer periphery of the die as shown in FIG. 2c are oriented opposite the die rotation to provide back pressure to minimize material flash between the container and the die during extrusion.

Fig. 2b shows a bottom perspective view of the inlet bridge die 12. In this view, the mold shows a series of fully penetrating ports 17. In use, the flow of plasticised material, gathered by the above-mentioned inwardly directed grooves 15 and outwardly directed grooves 13, passes through these penetrations 17, is then recombined in the welding chamber 21 and then flows around the mandrel 18 to produce the desired cross-section. The use of swirl grooves 13, 15, 19 to feed port 17 during rotation as a means of separating the flow of material (e.g., powder, flakes, billets, etc.) into distinct streams has never been known. This arrangement enables the formation of articles having non-circular hollow cross-sections.

Fig. 3 illustrates the separation of magnesium alloy ZK60 into multiple streams during the ShAPE process using an inlet bridge die method. (in this case, the materials are allowed to separate, rather than pass through the die bearing surfaces for assembly, for the effect and illustration of the separation feature). Conventional extrusion does not rotate and the addition of grooves can greatly impede material flow. But when there is rotation such as in the case of the ShAPE or friction extrusion, the swirl not only assists the flow but also significantly assists the inlet bridging die extrusion 17 in functioning and subsequently forming the non-circular hollow profile extrusion. Extrusion through an inlet bridge die process using a process involving rotation (such as ShAPE) is not effective for manufacturing articles having this configuration if no swirl grooves are fed to the inlet. The conventional linear extrusion process of the prior art does not teach the use of surface features to direct material into the inlet 17 during extrusion.

In the previously described and related applications, various methods and techniques are described in which the ShAPE technique and apparatus are shown to provide a number of significant advantages, including the ability to control microstructure (such as crystallographic texture) through cross-sectional thickness, while also providing the ability to perform various other tasks. In this specification we provide information on the formation of materials with non-circular hollow profiles using the ShAPE technique, and methods for manufacturing high entropy alloys, which are useful in various applications (e.g. projectiles). These two exemplary applications will be discussed in more detail below.

Figure 4a shows a schematic of the ShAPE process which uses a rotating tool to apply a load/pressure and at the same time the rotation helps apply a torsional/shear force to generate heat at the interface between the tool and the feedstock to help consolidate the material. In this particular embodiment, the arrangement of the ShAPE scheme is configured to consolidate High Entropy Alloy (HEA) arc-melted disks into dense disks. In this arrangement, the rotary punching tool is made of inconel (lnconel alloy) and has an Outer Diameter (OD) of 25.4mm, and the depth of the vortex on the punching face is 0.5mm and has a pitch of 4mm for a total of 2.25 revolutions. In this case, a thermocouple was incorporated into the stamping surface to record the temperature at the interface during processing. (see figure 4b) this scheme enables the stamp to rotate at speeds from 25 to 1500 RPM.

In use, both axial and rotational forces are applied to the material of interest, causing the material to plasticize. In extrusion applications, the plasticized material then flows over a die support surface sized to allow the plasticized material to be recombined with a particle size distribution and arrangement that is more superior than possible in conventional extrusion processes. As described in the prior related applications, this method provides many advantages and features that conventional prior art extrusion processes alone cannot achieve.

High entropy alloys are typically solid solution alloys formed from five or more major elements in equal or nearly equal molar (or atomic) ratios. While this arrangement may provide various advantages, it also provides various challenges, particularly in forming. Whereas conventional alloys typically contain a primary element that largely controls the basic metallurgy of the alloy system (e.g., nickel-based alloys, titanium-based alloys, aluminum-based alloys, etc.), in HEA, each of the five (or more) components of the HEA may be considered a primary element. Such advances in the production of materials may open the door to their ultimate use in a variety of applications. However, standard forming processes exhibit significant limitations in this regard. The hope of obtaining such results was demonstrated using a shupe type process.

In one example, a "low density" aicufe (mg) Ti HEA is formed. Starting with an arc fused gold pellet (button) as the precursor (pre-cure), the ShAPE process is used to simultaneously heat, homogenize and consolidate the HEA, thereby creating a material that overcomes the various problems associated with prior art applications and provides various advantages. In this particular example, commercially pure aluminum, magnesium, titanium, copper and iron are used at 10^-6HEA pellets were arc melted in a furnace under vacuum. Due to the high vapor pressure of magnesium, most of the magnesium evaporates and forms al1mg0.1cu2.5fe1ti1.5, rather than the expected Al1Mg1Cu1Fe1Ti1 alloy. The arc melted pellets described in the previous paragraph are easily crushed with a hammer and used to fill the die/powder chamber (fig. 4c) and the shear assisted extrusion process begins. The volume fraction of the filled material is less than 75%, but the material is consolidated when the tool is rotated at 500RPM under load control (with the maximum load set at 85MPa and 175 MPa).

Comparison of the arc melted material and the material developed under the ShAPE process showed various differences. The arc-melted globules of LWHEA exhibit a nucleated, dendritic microstructure, as well as a region containing intermetallic particles and pores. Using the smape process, these microstructural defects were eliminated, resulting in a single phase, refined grain, and pore-free LWHEA sample.

FIG. 5a shows a back-scattered SEM (BSE-SEM) image of an as-cast/arc-melted sample. The arc melted sample had a nucleated dendritic microstructure (where the dendrites were rich in iron, aluminum and titanium) and 15-30 μm in diameter, while the interdendritic regions were rich in copper, aluminum and magnesium. The aluminum is uniformly distributed throughout the microstructure. This microstructure is typical of HEA alloys. The interdendritic regions appeared to be rich in Al-Cu-Ti intermetallic compounds and confirmed by XRD as AICu₂And (3) Ti. XRD also confirmed Cu₂Mg phase, which was not determined by EDS analysis, and the entire matrix was BCC phase. The intermetallic compound forms a eutectic structure in the interdendritic region and has a length and width of about 5 to 10 μm. The interdendritic regions also have a porosity of about 1-2 vol% between them, and thus it is difficult to measure the density thereof.

Typically, this microstructure is homogenized by continuing heating for several hours to maintain a temperature near the melting point of the alloy. In the absence of thermodynamic data and diffusion kinetics for this new alloy system, it is difficult to predict the exact point at which the various phases form or precipitate, particularly with respect to various temperatures and cooling rates. In addition, the first and second substrates are,

further complications arise from the unpredictability regarding the durability of the intermetallic phase and the retention of its morphology even after heat treatment. Typical lamellar and long intermetallic phases are troublesome when subjected to conventional processing such as extrusion and rolling, and are also detrimental to mechanical properties (elongation).

The use of the ShAPE process enables the refinement of the microstructure without a homogenization heat treatment and provides a solution to the above-mentioned complexities. The arc-melted pellets (due to their respective porosity and presence of intermetallic phases) easily break into small pieces to fill the mold cavity of the ShAPE apparatus. Two separate runs were performed as described in table 1, where both processes produced discs 25.4mm in diameter and about 6mm in height. The disc was then sliced at the center to evaluate the change in microstructure as a function of its depth. Typically, during the ShAPE consolidation process; the shearing action causes structural deformation at the interface and increases the interface temperature; this is proportional to rpm and torque; while the linear motion and the heat generated by the shear cause consolidation. Depending on the time of the operation and the applied force, consolidation approaching the entire thickness can also be obtained.

Table 2: consolidation processing conditions for LWHEA

Run #	Pressure (MPa)	Tool RPM	Process temperature	Dwell time
					1	175	500		180s
2	85	500	600℃	180s

Fig. 6 a-6 d show a series of BSE-SEM images ranging from the substantially raw disc bottom to the fully consolidated area at the tool blank interface. There is a gradual change in microstructure from the bottom of the disk to the interface. The bottom of the disk has a microstructure similar to the microstructure depicted in fig. 5. But as the disk is inspected moving towards the interface, the dendrites become closely spaced in size (fig. 6 b). Intermetallic phases are still present in the interdendritic regions, but the porosity is completely eliminated. On a macroscopic scale, the disc appears more continuous and without any porosity from the top to the bottom 3/4 portion. Figure 6c shows the interface where the shearing action is more prominent. This region clearly distinguishes the as-cast dendritic structure from mixing and plastic deformation caused by shear action. The spiral pattern is observed from this area to the top of the disk. This is indicative of the stirring action and is due to the swirling pattern on the surface of the tool. This shearing action also results in comminution of the intermetallic particles and also helps to homogenise the material, as shown in figures 6c and 6 d. It should be noted that the entire process lasts only 180 seconds to homogenize, disperse and pulverize the intermetallic particles. The likelihood of some of these resulting intermetallic particles re-dissolving into the matrix is very high. The homogenization zone is approximately 0.3mm from the surface of the disk.

The use of the ShAPE apparatus and technique presents a new single step method for processing without preheating the billet. With this new method, the time required to homogenize the material is significantly reduced. Based on early work, the presence of shear and swirl aids the pulverization of the secondary phase and creates a helical pattern. All this provides an important opportunity for cost reduction of the final product without compromising performance and at the same time tuning the microstructure to the desired performance.

Many types of alloys exhibit high strength at room temperature and high temperature, good machinability, high wear and corrosion resistance. Such materials may be considered as alternatives for various applications. Refractory HE alloys can replace expensive superalloys used in applications such as gas turbines and expensive lnconel alloys used in coal gasification heat exchangers. The HE alloy with light weight can replace aluminum and magnesium alloy and be used for automobiles and airplanes. Using the shepe process to perform extrusion will enable these types of deployments.

While various preferred embodiments of the present invention have been shown and described, it is to be clearly understood that the invention is not limited thereto but may be embodied in various forms for implementation within the scope of the appended claims. From the foregoing it will be observed that numerous modifications may be effected without departing from the spirit and scope of the invention as defined by the appended claims.