阅读说明：本技术 航空发动机复材风扇叶片前缘钛合金加强边的制造方法 (Manufacturing method of titanium alloy reinforcing edge of front edge of composite fan blade of aircraft engine ) 是由 李细锋 蒋一帆 熊炜 陈军 李铭 于 2021-09-29 设计创作，主要内容包括：一种航空发动机复材风扇叶片前缘钛合金加强边的制造方法,通过热蠕变成形与切削的方式得到钛合金加强边的上、下薄壁预制件,通过切削的方式得到钛合金加强边的中间层块体预制件,然后通过接触面延伸出的耳片控制预制件之间的相对位置,通过芯模避免预制件在扩散连接过程发生变形,控制加强边的内腔成形精度,最后对装配后的三层预制件进行扩散连接得到钛合金加强边。本发明采用切削、热蠕变成形和扩散连接的复合方法加工薄壁深腔结构,能大幅提高材料利用率,显著缩短加工周期,保证前缘钛合金加强边的成形精度和质量。(The manufacturing method of the front edge titanium alloy reinforcing edge of the composite fan blade of the aero-engine comprises the steps of obtaining upper and lower thin-wall prefabricated parts of the titanium alloy reinforcing edge in a hot creep forming and cutting mode, obtaining a middle-layer block prefabricated part of the titanium alloy reinforcing edge in a cutting mode, controlling the relative position of the prefabricated parts through lugs extending out of a contact surface, avoiding deformation of the prefabricated parts in a diffusion connection process through a core mold, controlling the inner cavity forming precision of the reinforcing edge, and finally performing diffusion connection on three layers of prefabricated parts after assembly to obtain the titanium alloy reinforcing edge. The invention adopts a composite method of cutting, hot creep forming and diffusion connection to process the thin-wall deep cavity structure, can greatly improve the material utilization rate, obviously shortens the processing period and ensures the forming precision and quality of the front edge titanium alloy reinforced edge.)

1. A manufacturing method of a titanium alloy reinforcing edge at the front edge of a composite fan blade of an aero-engine is characterized in that upper and lower thin-wall prefabricated parts of the titanium alloy reinforcing edge are obtained in a hot creep forming and cutting mode, a middle-layer block prefabricated part of the titanium alloy reinforcing edge is obtained in a cutting mode, then the relative position between the prefabricated parts is controlled through lugs extending out of a contact surface, the prefabricated parts are prevented from deforming in a diffusion connection process through a core mold, the inner cavity forming precision of the reinforcing edge is controlled, and finally three layers of prefabricated parts after assembly are subjected to diffusion connection to obtain the titanium alloy reinforcing edge;

the ear is specifically as follows: the contact surface of the prefabricated part and the lug plate with holes formed by extending the core mould outwards; after the assembly is completed, the holes on the lugs on the two sides are in the same vertical position, and the positions of the prefabricated member and the core mold are controlled.

2. The method for manufacturing the titanium alloy reinforcing edge of the front edge of the composite fan blade of the aero-engine as claimed in claim 1, wherein inner cavities of the upper thin-wall prefabricated member and the lower thin-wall prefabricated member are matched with the front edge of the composite fan blade.

3. The method for manufacturing the titanium alloy reinforcing edge of the front edge of the composite fan blade of the aero-engine as claimed in claim 1, wherein the upper surface and the lower surface of the intermediate layer block prefabricated member are respectively attached to the upper thin-wall prefabricated member and the lower thin-wall prefabricated member, and the inner side surface of the intermediate layer block prefabricated member is matched with the front edge of the composite fan blade.

4. The method for manufacturing the titanium alloy reinforced edge of the front edge of the composite fan blade of the aero-engine as claimed in claim 1, wherein the outer surface of the core mold is matched with an inner cavity of the reinforced edge to ensure the forming precision of the inner cavity in the forming process.

5. The method for manufacturing the front edge titanium alloy reinforcing edge of the composite fan blade of the aero-engine as claimed in claim 1, wherein the upper and lower thin-walled preforms are obtained by performing hot creep forming on a titanium alloy thin plate to obtain a blank, further cutting the blank, cutting off an excess part, and processing a lug.

6. The method for manufacturing the titanium alloy reinforcing edge of the front edge of the composite fan blade of the aero-engine as set forth in claim 1, wherein the assembling is: the lugs of the prefabricated part extend out of the diffusion connection mold, and pins are inserted between the lugs to fix the core mold.

7. The method for manufacturing the titanium alloy reinforcing edge of the front edge of the composite fan blade of the aero-engine as claimed in claim 1, wherein the upper thin-wall prefabricated member, the lower thin-wall prefabricated member and the intermediate layer block prefabricated member are made of TC4 titanium alloy; the material used by the core mould, the upper mould and the lower mould is 310S stainless steel.

8. The method for manufacturing the titanium alloy reinforced edge of the front edge of the composite fan blade of the aero-engine according to claim 1, wherein the diffusion connection is realized by heating and pressurizing through a vacuum hot pressing furnace, the composite fan blade front edge titanium alloy reinforced edge is obtained by cooling along with the furnace after finishing heat preservation and pressure maintaining, finally taking out a core mold and cutting and removing a lug.

9. The method for manufacturing the titanium alloy reinforced edge of the front edge of the composite fan blade of the aero-engine according to claim 1 or 8, wherein the diffusion bonding is performed by firstly heating to 910 ℃, pressurizing to 10MPa, keeping the temperature and the pressure for 60min, and cooling the product to room temperature along with a furnace after the diffusion bonding is finished.

Technical Field

The invention relates to the technology in the field of aeroengines, in particular to a method for manufacturing a titanium alloy reinforcing edge of a front edge of a composite fan blade of an aeroengine.

Background

The carbon fiber composite material fan blade has excellent performances such as high specific strength, large specific modulus, good fatigue resistance, excellent damage tolerance capability and the like, and gradually replaces the traditional hollow titanium alloy blade to become the mainstream choice of commercial aircraft engines. However, when the front edge part of the composite material fan blade is impacted, delamination and damage are easy to generate, and the problems of glue failure, delamination and the like also occur, so that the comprehensive service performance of the fan blade can be obviously improved by adding the titanium alloy reinforcing edge on the front edge of the composite material fan blade.

In order to adapt to the shape of the front edge of the composite fan blade, the titanium alloy reinforcing edge is often provided with a complex deep-cavity thin-wall special-shaped structure. The titanium alloy front edge reinforcing edge is integrally machined by a cutting method, so that the material utilization rate is low, the machining time consumption is long, and the difficulty and the rejection rate of the integral part machined by cutting are high due to the complex shape of the cavity and the large thickness distribution gradient of the reinforcing edge.

Patent application No. 201711026455.0 discloses a titanium alloy reinforced edge obtained by a plurality of processes including hot press forming, laser welding, additive manufacturing, and nose cone post-treatment. The problem with this method is that the connection between the two side wall panels is by laser welding, with a significant fusion weld; the processing surface bonding strength formed by splicing the nose cone manufactured in an additive mode and the outer side surfaces of the two side wall plates is not high, the difference of the structure performance of the nose cone manufactured in an additive mode and the two side wall plates is extremely large, the service performance is poor easily, in addition, the additive manufacturing efficiency is low, the cost is high, and the method is not suitable for batch production. Patent application No. 202110426921.4, through cutting the flitch earlier, hot pressing obtains the prefab, carries out diffusion bonding to the prefab again and obtains the whole piece. The method has the problems that the reinforced edge is obtained by adopting the diffusion connection of two layers of prefabricated parts, but the prefabricated parts have the characteristics of distortion, large thickness distribution gradient and the like, so that the cutting amount is large, the material utilization rate is lower than 10 percent, and the manufacturing cost is high.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides a method for manufacturing the front edge titanium alloy reinforcing edge of the composite fan blade of the aero-engine, which adopts a composite method of cutting, hot creep forming and diffusion connection to process a thin-wall deep cavity structure, can greatly improve the material utilization rate, obviously shorten the processing period and ensure the forming precision and quality of the front edge titanium alloy reinforcing edge.

The invention is realized by the following technical scheme:

the invention relates to a method for manufacturing a titanium alloy reinforcing edge at the front edge of a composite fan blade of an aero-engine, which comprises the steps of obtaining upper and lower thin-wall prefabricated parts of the titanium alloy reinforcing edge in a hot creep forming and cutting mode, obtaining a middle-layer block prefabricated part of the titanium alloy reinforcing edge in a cutting mode, controlling the relative position between the prefabricated parts through lugs extending out of a contact surface, preventing the prefabricated parts from deforming in a diffusion connection process through a core mold, controlling the inner cavity forming precision of the reinforcing edge, and finally performing diffusion connection on three layers of prefabricated parts after assembly to obtain the titanium alloy reinforcing edge.

The inner cavities of the upper and lower thin-wall prefabricated parts are matched with the front edges of the composite fan blades.

The upper surface and the lower surface of the intermediate layer block prefabricated part are respectively attached to the upper thin-wall prefabricated part and the lower thin-wall prefabricated part, and the inner side surface of the intermediate layer block prefabricated part is matched with the front edge of the composite fan blade.

The outer surface of the core mold is matched with the inner cavity of the reinforcing edge and used for ensuring the forming precision of the inner cavity in the forming process.

The ear is specifically as follows: the contact surface of the prefabricated member and the core mold extend outwards to form a perforated lug. After the assembly is completed, the holes on the lugs on the two sides are in the same vertical position, and the positions of the prefabricated member and the core mold are controlled.

The upper thin-wall prefabricated member and the lower thin-wall prefabricated member are obtained by performing hot creep forming on a titanium alloy thin plate to obtain a blank, further cutting the blank, cutting off redundant parts and processing lugs to obtain the upper thin-wall prefabricated member and the lower thin-wall prefabricated member.

The assembling means that: the lugs of the prefabricated part extend out of the diffusion connection mold, and pins are inserted between the lugs to fix the core mold.

The material used for the upper thin-wall prefabricated member, the lower thin-wall prefabricated member and the middle layer block prefabricated member is preferably TC4 titanium alloy.

The material used for the core mold, the upper mold and the lower mold is preferably 310S stainless steel.

And the diffusion connection is realized by heating and pressurizing through a vacuum hot-pressing furnace, the core mold is cooled along with the furnace after heat preservation and pressure maintaining are finished, and finally the core mold is taken out, and the lug is cut to remove the lug, so that the titanium alloy reinforced edge of the front edge of the composite fan blade is obtained.

And in the diffusion connection, the temperature is firstly increased to 910 ℃, the pressure is increased to 10MPa, the heat preservation and pressure maintaining are carried out for 60min, and after the diffusion connection is finished, the product is cooled to the room temperature along with the furnace.

Technical effects

The titanium alloy reinforced edge of the front edge of the compound material fan blade of the aero-engine is obtained by performing diffusion connection on three prefabricated parts at one time, the upper prefabricated part and the lower prefabricated part are thin slices, the middle prefabricated part is a block, the upper thin-walled part and the lower thin-walled part are formed by hot creep forming and then cut, the shape of a blank is controlled in the hot creep forming process, and the thin-walled prefabricated part can be obtained by removing a small amount of redundant materials. The intermediate layer is obtained by direct cutting without further treatment.

Drawings

FIG. 1 is a schematic view of a titanium alloy reinforced edge of a leading edge of a composite fan blade of an embodiment;

FIG. 2 is a schematic view of upper and lower blank members of an example titanium alloy reinforcing flange;

FIG. 3 is a schematic illustration of a titanium alloy reinforcing rim according to an embodiment in layers;

FIG. 4 is a schematic view of an example mandrel;

FIG. 5 is a schematic view of the connection of the mandrel to the preform according to the embodiment;

FIG. 6 is a schematic view of an embodiment in assembly;

FIG. 7 is a schematic view of a mold closed according to an embodiment;

FIG. 8 is a schematic view of a connection piece after diffusion bonding according to an embodiment;

in the figure: the titanium alloy composite material comprises a titanium alloy reinforcing edge 1, an upper blank 2, a lower blank 3, an upper prefabricated part 4, a lower prefabricated part 5, a middle prefabricated part 6, a core mould 7, an upper mould 8, a lower mould 9, a guide pillar 10, a lug 11, a pin 12 and a connecting piece 13.

Detailed Description

The manufacturing method of the titanium alloy reinforced edge of the front edge of the composite fan blade of the aero-engine related by the embodiment adopts the composite working procedures of the sectional hot creep forming, the cutting and the diffusion connection to obtain the titanium alloy reinforced edge 1 of the front edge of the composite fan blade shown in the figure 1; respectively processing an upper blank 2 and a lower blank 3 shown in FIG. 2 by hot creep forming of an equal-thickness titanium alloy thin plate, cutting to obtain an upper prefabricated member 4 and a lower prefabricated member 5 shown in FIG. 3, and directly cutting a titanium alloy block to obtain an intermediate prefabricated member 6; then, diffusion connection is carried out on the upper prefabricated member 4, the middle prefabricated member 6 and the lower prefabricated member 5, a core mold 7 is arranged among the prefabricated members to ensure the accuracy of the inner cavity of the titanium alloy reinforcing edge, and two ends of the core mold 7 are fixed with the two prefabricated members through pins; finally, cutting off the connecting part to obtain the titanium alloy reinforced edge 1, which comprises the following steps:

s1: the geometry of the titanium alloy reinforcing flange 1 is determined. The reinforcing edge 1 is designed according to the profile of the composite material fan blade; the geometrical shapes of the upper prefabricated member 4, the middle prefabricated member 6 and the lower prefabricated member 5 are divided by the shape of the titanium alloy reinforcing edge, wherein the upper prefabricated member 4 and the lower prefabricated member 5 are thin-walled parts. The contact surface of the preform extends outward to form a holed tab 11 for location between the preform and the mandrel 7.

S2: according to the shape of the titanium alloy reinforcing edge 1, an upper blank part 2 and a lower blank part 3 are processed in a slicing mode in a hot creep mode of an equal-thickness thin plate, the two blank parts are equal-thickness curved surface thin-wall parts, and the shape of the curved surface is close to the geometric shape of the final titanium alloy reinforcing edge 1.

S3: processing the two blanks by cutting to obtain an upper prefabricated member 4 and a lower prefabricated member 5; the titanium alloy block is cut to obtain an intermediate layer preform 6. The three layers of prefabricated parts are respectively kept consistent with the corresponding parts of the titanium alloy reinforcing edges 1. The shapes of the inner and outer surfaces of the three-layer prefabricated member and the roughness of each surface are controlled by cutting and polishing.

S4: and spraying a solder stop agent on the contact surfaces of all parts which are not required to be connected, and assembling a lower die 9, a lower prefabricated part 5, a core die 7, an intermediate prefabricated part 6, an upper prefabricated part 4 and an upper die 8 in sequence. The moulds are connected by guide posts 10. The lugs of the prefabricated member extend out of the diffusion connection die, and the lugs 11 are connected with the core die 7 through pins 12 so as to fix the core die.

S5: the vacuum degree of the vacuum hot pressing furnace is pumped to 5 multiplied by 10^-3And after Pa, heating to 910 ℃, starting pressurizing to 10MPa, keeping the temperature and the pressure for 60min, and performing diffusion connection on the three-layer prefabricated part. And after the diffusion bonding forming is finished, cooling the diffusion bonding product to room temperature along with the furnace.

S6: the connecting member 13 is removed after the diffusion bonding is completed. The pin 12 and the core mold 7 on the tab 11 are removed, and the tab 11 is removed by cutting, thereby obtaining the titanium alloy reinforcing flange 1.

Through specific experiments, the method is operated at 10MPa, 910 ℃ and under the condition of heat preservation and pressure maintenance for 60min, and the pressing amount is 1mm, and the obtained experimental data are as follows: the prefabricated member has good diffusion connection condition, and the material utilization rate reaches more than 40 percent.

In conclusion, the blank is obtained through the hot creep of the equal-thickness thin plate, only the thin plate is formed into a curved surface shape in the process, the wall thickness is not changed, the processing difficulty is low, the processing efficiency is high, and the difficulty of subsequent surface polishing is reduced; the inner and outer molded surfaces of the wall plate are controlled in the hot creep process, the processing of the inner and outer molded surfaces of the upper and lower prefabricated parts is avoided, the material utilization rate is improved to more than 40 percent from 1 percent of full cutting and 10 percent of two-layer welded parts, and the size precision of the wall plate is better ensured while the manufacturing cost is greatly reduced; the diffusion connecting area avoids the round corner part at the front end of the reinforcing edge, which is easy to be impacted, so that the forming quality and the impact resistance of the product are improved while the processing difficulty of the inner profile of the reinforcing edge is reduced; in the diffusion connection process, the forming precision and quality of the inner cavity of the titanium alloy reinforcing edge are ensured by adopting the core die, the core die is simply matched through the pins, the assembly and the taking out are easy, and the reuse of the core die can be realized; the inner cavity of the die ensures the dimensional accuracy of the outer contour of the titanium alloy reinforcing edge in the diffusion connection process.

The foregoing embodiments may be modified in many different ways by those skilled in the art without departing from the spirit and scope of the invention, which is defined by the appended claims and all changes that come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.