阅读说明：本技术 多工艺合金包覆 (Multi-process alloy cladding ) 是由 P·奈特 E·加玛彻 于 2020-02-26 设计创作，主要内容包括：提供了一种产生包覆金属部件的方法。该方法包括爆炸接合包含基础层和中间层的板材。然后将爆炸接合的板材切割成棒条,用包覆层将其辊压接合。最终从辊压接合棒条制造部件。该解决方案使部件能够具有材料组合,和对于多于单一接合工艺的用途更优化的所得物理性能。(A method of producing a clad metal component is provided. The method includes explosion bonding a sheet material including a base layer and an intermediate layer. The explosion bonded sheet is then cut into rods which are roll bonded with a clad layer. The parts are finally manufactured from roll bonded bars. This solution enables the component to have a combination of materials and resulting physical properties that are more optimized for use with more than a single joining process.)

1. A metal transition component, comprising:

a combination of a cladding layer, an intermediate layer and a base layer,

the component having a component width, a component thickness, and a component length;

the component is formed by a method comprising:

explosively forming a sheet having the intermediate layer metallurgically bonded to the base layer, the sheet having a sheet width greater than the component width and a sheet length greater than the component length;

cutting a bar from the sheet material, the bar having a width less than the sheet material width and a length greater than the member length;

rolling the clad layer onto the bar to create a metallurgical bond between the intermediate layer and the clad layer; and the number of the first and second electrodes,

fabricating the component from the metallurgically bonded clad layer, the base layer and the intermediate layer.

2. The component according to claim 1, wherein the intermediate layer is made of titanium.

3. The component of claim 1, wherein the base layer is made of steel.

4. The component according to claim 1, wherein the cladding comprises aluminum having a purity of less than 99%.

5. The component of claim 1, wherein the cladding layer comprises aluminum having a strength greater than 200 MPa.

6. The component of claim 1, wherein the method further comprises heat treating the clad layer after the rolling.

Background

Innovations in materials continue to make engineering solutions lighter, more powerful, less expensive, and more durable. Where a single material can be optimized to have some properties ideally suited for a given application, there is often a tradeoff between material properties. Rather than attempting to optimize a single material and tolerate compromises, metallurgical bonding of metals offers the advantage of producing a single material made of multiple metals and combining favorable material properties.

A metallurgical bond is an atomic bond between two metals. The method of achieving bonding begins with surface preparation, in which oxides on the metal are removed. The bonding may then be generated by heat, pressure and momentum. There are several methods of producing metallurgical bonds, each with its own advantages and disadvantages.

Explosive bonding may produce a metallurgical bond through detonation of an explosive material on two or more separate cold metal sheets. The momentum of the sheet material and the resulting impact have sufficient energy to join the material. The disadvantage of rapidly joining large quantities of material in a single detonation is the lack of precise control over the detonation process. As a result, large amounts of material may be inexpensively joined, but combinations of materials that require precision may not be possible. Explosive bonding works well for joining hard materials such as steel to stainless steel, but can become difficult when joining alloyed aluminum and thin or soft materials.

Diffusion bonding is a method of creating a metallurgical bond using only heat and pressure. Two or more metals are stripped of their oxides and placed in contact within a vacuum enclosure to prevent new oxides from forming. The heat and pressure slowly allow diffusion to occur, creating a metallurgical bond. While diffusion bonding provides precise control over the connection variables and geometry, it is slow, expensive and has practical limitations on size.

Roll bonding is another method of creating a metallurgical bond. Two or more metals are mechanically stripped of their oxides and then they are thickness-reduced between two rolls. This depression results in the oxide layer breaking, raw material contact, and metallurgical bond formation. Depending on the material and material combination, hot, warm or cold individual materials can be rolled. Roll bonding provides a good balance between process control, process flexibility and cost.

The invention relates to a bimetal cladding transition body and a manufacturing method thereof. The present invention takes advantage of the benefits of roll and explosion bonding. In more detail as an exemplary application, the present invention may be optimally used to produce high temperature resistant and strong clad welded transitions for use in the aluminum smelter industry.

Drawings

Preferred embodiments of the present invention will be described below with reference to the following drawings:

FIG. 1 is a front perspective view of a welding anode assembly according to the present invention.

FIG. 2 is a front perspective view of a clad transition according to the present invention, shown in use in the welded anode assembly of FIG. 1.

Fig. 3 is a front perspective view of an explosion bonded panel used to create the clad transition shown in fig. 2.

Fig. 4 is a front perspective view of a blast-splice bar made from the sheet material of fig. 3.

Fig. 5 is a cross-sectional view of the explosion-bonded rod of fig. 4.

Fig. 6 is a side view of a roll bonding process that adds a cladding layer to the explosion bonded rod of fig. 5.

FIG. 7 is a flow chart illustrating a process and method for producing the clad transition of FIG. 2.

Detailed Description

The many components and methods used in the present invention are widely known and used in the field of the present invention, and their exact nature or type is not necessary for those skilled in the art to understand the present invention; therefore, they will not be discussed in detail. For example, conventional welding is well known in the art of metal making and aluminum smelting, and does not require detailed explanation for understanding and practicing the present invention without undue experimentation.

Aluminum production is a well known and well established technology. Bauxite is mined from the earth and refined to alumina. The alumina is then converted to aluminum by a smelting process. Oxygen is removed from the alumina to produce pure aluminum. Pure aluminum may be mixed with other elements to produce alloyed aluminum, or may not be mixed. Depending on the final composition of the aluminum, it is designated as an identification series, such as 1100, 4032, 6061 or 7075. Each series has known physical, electrical and thermal properties and can be formed into a desired shape by rolling into a sheet or extrusion. Some alloys are available only as extrusions rather than as sheets.

The smelting process is primarily accomplished by a carbon roasting process in which the carbon block is placed in an alumina bath to electrically cause oxygen in the alumina to combine with carbon in the carbon block to produce carbon dioxide.

In fig. 1, a carbon anode assembly 10 according to the present invention is shown. The anode assembly 10 is used to conduct the positive charge of the smelting process through the alumina and into the cathode bus (not shown). The anode assembly 10 includes anode bars 12 that are electrically connected to a bus bar system (not shown). Typically, the anode rods 12 are made of 4032 aluminum or an aluminum alloy that provides optimized strength and electrical performance. The anode rods 12 must be able to support the weight of the carbon blocks 16 and resist the reaction forces of the anode assembly 10 as it moves. The smelting process is carried out at a significant temperature, which is large enough to weaken or melt the anode rods 12. To withstand the heat, the yoke (yoke)14 is made of a temperature resistant material such as steel or copper and supports the carbon blocks 16 in areas where the heat is not acceptable for the anode bars 12. Because conventional welding between aluminum and steel is not possible, a weld transition is inserted between the yoke 14 and the anode rod 12. The prior art weld transition is metallurgically bonded to the dissimilar metals, formed by roll bonding or explosion bonding. The prior art welded transition bodies are made of low carbon steel and high purity aluminum such as 1100 or 1050. High purity aluminum is very conductive and can be easily bonded by explosion and roll bonding. The anode rod 12 is connected to the yoke 14 by welding the aluminum side of the prior art welded transition to the anode rod 12 and welding the steel side of the prior art welded transition to the yoke 14.

The novel clad transition body 30 welded to the anode assembly 10 is shown separately in fig. 1 and 2, and is shown separately in fig. 2. Clad transition piece 30 includes base layer 32, intermediate layer 34, and cladding layer 36. Base layer 32 is preferably steel and is preferably 1008 or an alloy of a 36. Alternatively, the base layer 32 may be made of copper. Preferably, the base layer 32 is 0.275 to 1.5 inches in height, but the invention should not be construed as being limited to any particular thickness. Metallurgically bonded to base layer 32 is intermediate layer 34. Metallurgically bonded to intermediate layer 34 is cladding layer 36 made of an aluminum alloy, rather than pure aluminum as used in the prior art. The intermediate layer 34 is intended to resist diffusion of iron into the aluminum, causing failure of the metallurgical bond at high temperatures. The breakdown of metallurgical bonds is accomplished by the Kirkendall effect, which is well known in the art of metallurgically bonding dissimilar metals. In a preferred embodiment according to the present invention, the intermediate layer 34 is titanium having a thickness of 1 mm, although other thicknesses may be used. In addition, other materials may be used for the intermediate layer 34 in place of titanium, including but not limited to nickel and tantalum.

Prior art roll bonded weld transitions use chromium as an intermediate layer. Without the chromium interlayer, the Kirkendall effect can occur at temperatures below 500 degrees celsius. Chromium prevents diffusion between dissimilar metals and allows prior art roll bonded welded transitions to withstand temperatures above 500 ℃. Modern smelters may not produce a temperature of 400C at the point between the anode bar 12 and the yoke 14 during normal use, but the higher temperature tolerance provides protection to the anode assembly 10. Chromium is well suited for roll bonding prior art welded transitions because it can be electrodeposited onto steel prior to roll cladding the aluminum layer. A pure aluminum layer was roll bonded to the steel with chromium. Roll bonded aluminum can be made from sheet or extruded aluminum due to the ability to roll the bar. Titanium is not feasible as an intermediate layer with aluminum and steel when rolled together due to the temperature limitations of aluminum. Roll bonding of steel to titanium is extremely challenging due to the high temperatures required and the formation of oxides that hinder bonding. One advantage of roll bonding over explosion bonding is that the alloyed aluminum can be readily bonded directly to the steel.

Alternatively, prior art explosively bonded welded transitions have used titanium as the intermediate layer. Titanium provides a temperature resistance of greater than 550 ℃. Explosion bonding of titanium and aluminum to steel makes possible at lower temperatures (compared to roll bonding). Since the dimensions of the sheet are optimally adapted to the economics of the explosion process, chromium is less suitable for explosive joining due to the potential dimensional requirements of chromium plated cans. Also due to the size of the explosion bonded sheet, which is typically many feet wide by many feet long, the explosion bonded aluminum must be available in sheet form rather than as an extrusion. Furthermore, explosive bonding is not feasible for directly bonding alloyed aluminum to steel or titanium. If the alloyed aluminum is joined in an explosive bonding process, a highly bondable layer of low strength pure aluminum is joined between the pure cladding aluminum and the base metal. The strength of the resulting transition is only as strong as the pure aluminum layer that limits the overall strength of the clad assembly. A pure aluminum bond layer is the weakest link in a clad transition for explosive bonding.

The novel clad transition 30 is produced by roll bonding and explosion bonding. Explosive bonding is used to metallurgically bond the base layer 32 to the intermediate layer 34 in sheet form. Clad layer 36 is then roll bonded to intermediate layer 34 to form clad transition 30. The clad transition 30 has the thermal "Kirkendall" resistance benefits of titanium, as well as the strength benefits of direct bonding of the alloy aluminum used for the clad layer 36. According to the present invention, cladding 36 is made of highly conductive alloy 6101, although other alloys may be used, such as, but not limited to 6063,4032,5083,3003 and 6061. Alloy 6101 has conductivity properties approaching that of pure aluminum, which also provides increased strength relative to pure aluminum. Preferably, cladding layer 36 has alloying elements including, but not limited to, one or more of magnesium, zinc, copper, manganese, iron, and silicon. According to a preferred embodiment of the invention, the cladding layer 36 comprises more than two tenths by weight of magnesium in aluminium. According to the present invention, alloy cladding layer 36 has a strength greater than 1000 series aluminum. Alloy cladding layer 36 may have a final tensile strength greater than 100 MPa. In addition, alloy clad layer 36 may increase strength due to work hardening caused by roll bonding. Alloy clad layer 36 may also be heat treated after rolling. The alloy cladding layer 36 may have a resulting strength greater than 200 MPa. Alloy cladding layer 36 may have an aluminum purity of less than 99%.

The manufacturing method 60 is used to create the novel clad transition 30 and is shown in fig. 7. The base layer 32 and the intermediate layer 34 are prepared for explosive bonding step 63. Layers 32 and 34 are sanded or ground to remove the oxide layer that promotes explosive bonding. Step 63 of explosion bonding is well known in the art of metallurgical bonding, and the exact steps are not necessary to those skilled in the art to understand and appreciate the present invention.

After the step 63 of explosive bonding, an explosive sheet 40 is produced, as shown in fig. 3. The base layer 32 is bonded to the intermediate layer 34. The sheet 40 is flattened and then cut to produce explosive bars 50. The bar 50 comprises the base layer 32 and the intermediate layer 34 and has a width and length optimized for roll bonding. The width of the sheet material 40 is reduced by a step 64 of cutting into bars. Preferably, the width of the bar 50 is less than 10 inches, but may be any width optimized for a particular mill. The cross-section of the bar 50 is shown in figure 5.

The bar 50 is then roll bonded to cladding layer 36 by roll bonding step 66. The roll bonding step 66 is illustrated by fig. 6. Intermediate layer 34 has been metallurgically bonded to base layer 32 by explosive bonding step 63. A coating 36 is placed on top of the bar 50. Preferably, the bar 50 and cladding 36 are heated to over 600F and less than 700F, although the thermal cladding 36 may also be rolled onto the bar 50 at room temperature or hotter than 700F. The two rollers, 51A and 51B, reduce the thickness of the clad layer 36, which causes a metallurgical bond between the alloy materials of the intermediate layer 34 and the clad layer 36. The inlet height 38A of the cladding 36 is typically twice the height of the outlet height 38B. Preferably, the outlet height 38B is one-half inch.

Finally, the manufacturing step 67 results in optimized dimensions for the clad transition body 30 used within the anode assembly 10. Manufacturing step 67 may utilize saw cutting, machining, water jet cutting, or any conventional method of cutting metal. The final dimensions of the cladding 30 are optimized for welding to the anode assembly 10 and the length and width are typically in the range of one inch to less than 10 inches.

The present invention clad transition 30 is significantly stronger than prior art explosion bonded welded transitions limited to pure aluminum. The present invention is not limited to the use of alloys that are only available in sheet or plate form. The present invention also has a higher temperature resistance than can be produced with a roll bonding process alone by using a diffusion resistant interlayer material that is most easily bonded by explosive bonding. The present invention can be optimally adapted for a given smelting application by selecting an aluminum alloy for the clad layer 36 that provides acceptable electrical resistance and strength, which is only available in the form of extrusions and direct roll bonding.

Other embodiments are possible within the spirit and scope of the invention. While three layers are shown, each layer being bonded to an intermediate layer in a different bonding process, it should be understood that any number of layers may be used. For example, more than two layers may be joined during the explosion, by exploding them with one explosion or re-exploding the joined panels with a new layer. Similarly, roll bonding may be accomplished with more than two material layers in one rolling process, and multiple layers may be added sequentially with multiple rolling passes. Cladding 30 may be bonded using explosion and roll bonding to have more than three layers.

While the clad transition body system described herein constitutes a preferred embodiment of the invention, it is to be understood that the invention is not limited to these precise forms of assembly, process and method, and that changes may be made therein without departing from the scope and spirit of the invention.