Method for high-reliability connection and size-accurate control of disc core and disc rim of double-titanium alloy disc

Abstract

The application discloses a high-reliability connecting and size-accurate control method for a disc core and a disc rim of a double-titanium alloy disc, which comprises the following steps: a coaxial conical surface is formed to divide the disc core and the disc rim of the double-titanium alloy disc; a coaxial circular arc line which is in contact with the outside of the coaxial conical surface and is a circular arc line is formed to form a disc rim combined circular arc conical surface; a disc core and a disc rim blank are prepared; the disc core and the disc rim blank are installed on an inertial friction welding device, and after the rotating speed and the upsetting pressure are set, the disc core and the disc rim blank are relatively rotated at a low rotating speed; the pressure required by high-temperature plastic deformation is calculated, and after the rotating speed and the pressure maintaining time are set, the disc core and the disc rim blank are relatively rotated at a high rotating speed to prepare a high-temperature and high-strength double-titanium alloy disc blank. According to the method, the special combined surface structure and size design of the disc core and the disc rim are adopted, the high reliability of plastic deformation connection of the inertial friction welding is achieved, and the size-accurate distribution of the connecting position is achieved, so that the high-temperature and high-load performance requirements of a new generation of aero-engine titanium alloy disc are met.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of key parts of an aero-engine, in particular, relates to a high-reliability connection and size accurate control method for a disc core and a disc rim of a dual-titanium alloy disc. BACKGROUND

[0002] During the service of the aero-engine titanium alloy disc, the dual effects of high-speed rotation and high-temperature gas will cause the disc to bear complex thermal and mechanical coupling, and the temperature and load bearing performance of the disc is often required to be high. Titanium alloy materials with high yield strength ratio are the core materials for manufacturing the disc, but due to the material properties of single high-temperature or high-strength titanium alloy, which can only bear high temperature or high strength, the temperature and load bearing capacity of the existing titanium alloy disc is limited, and it cannot meet the rapid development demand of the high thrust-to-weight ratio of the new generation of aero-engines.

[0003] The dual-titanium alloy disc is prepared by connecting high-temperature titanium alloy and high-strength titanium alloy, which can take advantage of the performance of the two materials to meet the high-temperature and high-strength service conditions of the engine disc, but how to realize the high-reliability connection and size accurate control of the disc core and the disc rim of the dual-alloy disc is a problem. The fusion welding, additive manufacturing and other processes can realize the connection of the dual-titanium alloy, but the defects such as coarse grains and pores generated by melting at the dual-alloy connection part will weaken the performance, and cannot meet the high-performance demand of the disc.

[0004] The inertial friction welding and linear friction welding solid-phase connection processes generate plastic deformation at the connection part through friction heating, and then realize the high-reliability connection of the connection part, which is expected to meet the high-performance demand of the disc, but the size fluctuation change of the connection part along the circumferential direction will affect the balance of the load bearing performance of the dual-alloy disc, therefore, the high reliability of the connection part and the size distribution consistency along the circumferential direction are the key to the performance improvement of the high-temperature / high-strength dual-alloy disc, and the dual-alloy disc friction welding connection preparation process and method need to be strictly controlled.

[0005] According to the above description of the related implementation scheme, the main shortcomings of the prior art are summarized as follows:

[0006] 1) At present, the centrifugal impeller mostly uses titanium alloy or high-temperature alloy integral blade disc, and the titanium alloy centrifugal impeller cannot meet the simultaneous requirements of high strength and high temperature resistance; the high-temperature alloy centrifugal impeller can meet the requirements of strength and temperature, but the high-temperature alloy has a large density, resulting in a large mass of the impeller;

[0007] 2) The fusion welding, additive manufacturing and other processes can realize the connection of the dual-titanium alloy, but the defects such as coarse grains and pores generated by melting at the dual-alloy connection part will weaken the performance, and cannot meet the high-performance demand of the disc. SUMMARY

[0008] The application provides a high-reliability connecting and size-accurate control method for a disc core and a disc rim of a dual-titanium alloy disc, to solve the technical problem that the existing titanium alloy centrifugal impeller cannot simultaneously meet the requirements of high strength and high temperature resistance, and although the processes such as fusion welding and additive manufacturing can realize the connection of the dual-titanium alloy, the coarse grains and pores generated by melting at the dual-alloy connecting part weaken the performance and cannot meet the high-performance requirements of the disc.

[0009] The technical scheme adopted by the application is as follows.

[0010] The high-reliability connecting and size-accurate control method for the disc core and the disc rim of the dual-titanium alloy disc comprises the following steps: disc core combination straight-line conical surface design: taking the load bearing, temperature bearing and structural size of the disc as the theoretical basis, a coaxial conical surface is drawn to divide the disc core part and the disc rim part of the dual-alloy disc, and the coaxial conical surface is the disc core combination straight-line conical surface of the disc core; disc rim combination circular-arc conical surface design: according to the high-temperature plastic thermal deformation strain control principle of the titanium alloy, a coaxial circular-arc line which is in contact with the outside of the coaxial conical surface and is a circular-arc line is drawn, and the conical arc surface formed by the coaxial circular-arc line rotating one round is the disc rim combination circular-arc conical surface of the disc rim; disc core and disc rim blank preparation: a disc core blank with the disc core combination straight-line conical surface as the outer conical surface is prepared by selecting a high-strength titanium alloy material, and a disc rim blank with the disc rim combination circular-arc conical surface as the inner conical surface is prepared by selecting a high-temperature titanium alloy material; low-rotation coaxiality adjustment: the disc core blank and the disc rim blank are respectively arranged on the inertial friction welding equipment, and after the rotation speed and the upset pressure of the inertial friction welding are set, the disc core blank and the disc rim blank are relatively frictionally rotated at a low rotation speed; high-rotation connecting preparation: based on the high-temperature and high-strength titanium alloy thermal deformation flow stress constitutive equation, and by substituting the area of the disc core combination straight-line conical surface, the pressure required for high-temperature plastic deformation is calculated, and after the rotation speed and the pressure holding time are set, the disc core blank and the disc rim blank are frictionally rotated at a high rotation speed to prepare a high-temperature and high-strength dual-alloy disc blank.

[0011] Further, the step of "disc core combination straight-line conical surface design" specifically comprises the following steps: a plan view is designed based on the maximum diameter section of the disc, a coaxial circumference surface with a diameter of ΦD is drawn to divide the disc core part and the disc rim part; a coaxial conical line passing through the base point formed by the intersection of the disc core axial center position radial surface and the coaxial circumference surface is drawn to intersect the two ends of the disc core, and the conical surface formed by the coaxial conical line rotating one round is the coaxial conical surface.

[0012] Further, the coaxial conical surface formed by the coaxial conical line rotating one round has a small-end conical surface diameter of ΦD1, a large-end conical surface diameter of ΦD2, and a conical surface thickness H between the small-end conical surface and the large-end conical surface, and the range of (ΦD2-ΦD1) / H is 0.04≤(ΦD2-ΦD1) / H≤0.3.

[0013] Further, the step of "designing the disc rim combined circular arc conical surface" comprises the following steps: designing a plan view with the maximum diameter profile of the disc, forming offset lines intersecting the two end surfaces of the disc rim by offsetting the coaxial conical line outward by a distance, and forming a coaxial circular arc line passing through the three intersection points of the two intersection points of the offset lines and the two end surfaces of the disc rim, the intersection point of the axial center position radial surface of the disc core and the coaxial surface, and rotating the coaxial circular arc line to form a conical arc surface.

[0014] Further, in the step of "designing the disc rim combined circular arc conical surface", the offset line is parallel to the coaxial conical line, and the offset distance X is 0.1mm≤X≤3mm.

[0015] Further, in the step of "designing the disc rim combined circular arc conical surface", the two intersection points of the offset line and the two end surfaces of the disc rim are respectively intersection points A and B, and the intersection point of the axial center position radial surface of the disc core and the coaxial surface is intersection point E; and the coaxial circular arc line is formed at the positions of points A, B and E.

[0016] Further, in the step of "preparing the disc core and disc rim blanks", the corresponding high-strength titanium alloy material is selected according to the service temperature and stress distribution of the disc core, and the corresponding high-temperature titanium alloy material is selected according to the service temperature and stress distribution of the disc rim.

[0017] Further, in the step of "low-speed coaxiality adjustment", the disc core blank is installed at the propulsion end of the inertia friction welding device, the disc rim blank is installed at the rotating end of the inertia friction welding device, the inertia friction welding speed is set to 5-30 revolutions per minute, the upset pressure is set to 0.5-10 MPa, and the disc core blank and the disc rim blank are relatively frictionally rotated at a low speed.

[0018] Further, in the step of "high-speed connection preparation", based on the high-temperature and high-strength titanium alloy thermal deformation flow stress constitutive equation, the required pressure for the high-temperature plastic deformation of the disc core blank and the disc rim blank is calculated by substituting the disc core combined linear conical surface area S, and the average value of the required pressure is taken as the inertia friction welding upset pressure P.

[0019] Further, in the step of "high-speed connection preparation", the speed is set to 350-450 revolutions per minute, and the pressure holding time is ≤20s, so that the disc core blank and the disc rim blank are frictionally rotated at a high speed to realize plastic thermal deformation connection, thereby preparing a high-temperature / high-strength double-alloy disc blank.

[0020] The present application has the following advantages:

[0021] The disc core and disc rim high-reliability connecting and size accurate control method of the dual-titanium alloy disc of the application, according to the load bearing, temperature bearing and structure size characteristics of the engine disc, and according to the plastic deformation strain control principle of titanium alloy, on the basis of the traditional inertia friction welding process, through the special inner and outer taper surface structure and size design of the disc core and disc rim, then the relative friction motion of the disc core and disc rim at low speed is realized by the inertia friction welding equipment, the size accurate adjustment and control of the connecting part of the disc core and disc rim are realized, finally the relative friction heating motion of the disc core and disc rim at high speed is realized, the solid-state connection is realized through the plastic thermal deformation, the high-temperature / high-strength dual-alloy disc is prepared, the high-reliability connection and size accurate control of the connecting part are realized, the problems of the performance weakening of the connecting part of the dual-alloy disc and the size fluctuation affecting the performance uniformity are solved, compared with the ordinary inertia friction welding dual-alloy disc preparation method, the method of the application also has the following advantages:

[0022] In step S10, the disc core part and disc rim part of the dual-alloy disc are divided by the coaxial conical surface according to the load bearing, temperature bearing and structure size of the disc, and the coaxial conical surface is the disc core connecting straight-line conical surface, that is, the shape and size of the disc core connecting straight-line conical surface are designed first to realize the accurate determination of the connecting part position of the disc core and disc rim of the dual-alloy disc, and ensure that the high-temperature / high-strength titanium alloy material plays the role of high temperature bearing and high load bearing of the disc;

[0023] In step S20, according to the high-temperature plastic thermal deformation strain control principle of titanium alloy, the coaxial circular arc line which contacts the outer side of the coaxial conical surface and is an arc line is made, so that the convex shape and size of the disc rim outer circular arc conical surface are designed, the disc core and disc rim connecting surface is contacted from the circular line surface to the circular arc surface, so that the air possibly entering the connecting part of the two is fully discharged, and the high-quality connection in the high-temperature plastic deformation range of the disc core and disc rim connecting surface is realized;

[0024] In step S40, through the low speed and small upset force setting of the inertia friction welding equipment, the disc core blank and disc rim blank can realize the automatic adjustment and control of the coaxiality of the disc core and disc rim through the low-speed rotational friction motion, the size fluctuation of the connecting part of the two in the circumferential direction is prevented, and the conditions for the size accurate control of the connecting part are provided;

[0025] In step S50, through the high-speed friction rotation of the disc core blank and disc rim blank, the high-temperature plastic deformation of the conical connecting surface of the disc core and disc rim is realized, and according to the titanium alloy flow stress constitutive equation and the disc core connecting straight-line conical surface area, the inertia friction welding upset pressure is accurately calculated, and by cooperating with the control of the rotational speed and pressure holding time, the high-quality preparation of the high-temperature / high-strength dual-alloy disc blank is realized.

[0026] Therefore, the method of the application can not only play the high reliability of the plastic deformation connection of the inertia friction welding, but also realize the size accurate distribution of the coaxial connection part of the disc core and the disc rim, can meet the high temperature bearing and high load bearing performance requirements of the new generation of aero-engine titanium alloy disc, can prepare a high temperature / high strength dual alloy disc according to the requirements of the aero-engine disc, realize the high quality connection and size accurate control of the two alloy materials of the disc core and the disc rim, and has great popularization and application value in production.

[0027] In addition to the purposes, features and advantages described above, the application has other purposes, features and advantages. The application will be further described below with reference to the drawings. BRIEF DESCRIPTION OF DRAWINGS

[0028] The accompanying drawings, which form a part of this application, are included to provide a further understanding of the application, illustrate the preferred embodiments of the application and aid in explaining the application. In the drawings:

[0029] Figure 1 (a) is a schematic diagram of the disc core and disc rim part of the coaxial circumferential surface with a diameter of ΦD in the maximum diameter cross-sectional plane of the disc;

[0030] Figure 1 (b) is a schematic diagram of the intersection of the coaxial circumferential surface and the disc core center position radial surface in the maximum diameter cross-sectional plane of the disc;

[0031] Figure 1 (c) is a schematic diagram of the intersection of the coaxial conical surface and the two ends of the disc core, forming a conical small end surface with a diameter of ΦD1, a large end surface with a diameter of ΦD2, and a thickness of H;

[0032] Figure 2 (a) is a schematic diagram of the intersection of the coaxial conical line outward offset distance X and the two end surfaces of the disc rim;

[0033] Figure 2 (b) is a schematic diagram of the intersection points A, B of the offset line and the two end surfaces, and the intersection point E of the disc core center position radial surface and the coaxial circumferential surface;

[0034] Figure 2 (c) is a schematic diagram of the coaxial circular arc line formed by the positions of points A, B and E;

[0035] Figure 3 (a) is a schematic diagram of the structure of the disc rim blank obtained by machining;

[0036] Figure 3 (b) is a schematic diagram of the structure of the disc core blank obtained by machining;

[0037] Figure 4(a) is a schematic diagram of the disc edge blank rotating at low speed to achieve automatic coaxial adjustment with the disc core blank;

[0038] Figure 4 (b) is a schematic diagram of the disc core blank rotating at low speed to achieve automatic coaxial adjustment with the disc edge blank;

[0039] Figure 5 (a) is a schematic diagram of the high-speed frictional rotation of the blank body at the edge of the disk;

[0040] Figure 5 (b) is a schematic diagram of the disc core blank undergoing high-speed frictional rotation.

[0041] Figure 6 This is a schematic diagram of a high-temperature / high-strength bialloy disk blank prepared by inertial friction welding of bialloy disks;

[0042] Figure 7 (a) is a design based on the disc core and the straight conical surface design steps, taking into account the disc's load-bearing capacity, temperature resistance, and structural dimensional requirements. Figure 1 ;

[0043] Figure 7 (b) is a schematic diagram of the IMI834 / Ti6246 bimetallic blank prepared during the specific design process. Figure 1 ;

[0044] Figure 8 (a) is a design based on the disc core and the straight conical surface design steps, taking into account the disc's load-bearing capacity, temperature resistance, and structural dimensional requirements. Figure 2 ;

[0045] Figure 8 (b) is a schematic diagram of the IMI834 / Ti6246 bimetallic blank prepared during the specific design process. Figure 2 . Detailed Implementation

[0046] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in many different ways as defined and covered below.

[0047] Reference Figures 1-6 A preferred embodiment of the present invention provides a method for highly reliable connection and precise dimensional control of a dual titanium alloy disk core and rim, comprising the following steps:

[0048] S10: Disc core combined with straight conical surface design: Based on the load-bearing capacity, temperature resistance and structural dimensions of the disc, a coaxial conical surface is made to divide the disc core part and the disc edge part of the double alloy disc, and the coaxial conical surface is the disc core combined with the straight conical surface.

[0049] S20: Disc rim combined circular arc conical surface design: according to the strain control principle of high-temperature plastic thermal deformation of titanium alloy, a coaxial circular arc line is made in contact with the outer side of the coaxial conical surface and is a circular arc line, and the conical arc surface formed by rotating the coaxial circular arc line for one revolution is the disc rim combined circular arc conical surface of the disc rim;

[0050] S30: Disc core and disc rim blank preparation: high-strength titanium alloy material is selected to prepare a disc core blank with a disc core combined straight line conical surface on the outer conical surface, and high-temperature titanium alloy material is selected to prepare a disc rim blank with a disc rim combined circular arc conical surface on the inner conical surface;

[0051] S40: Low-speed coaxiality adjustment: the disc core blank and the disc rim blank are respectively arranged on the inertial friction welding equipment, and the rotation speed and the upsetting pressure of the inertial friction welding are set, and then the disc core blank and the disc rim blank are relatively frictionally rotated at low speed;

[0052] S50: High-speed connection preparation: based on the high-temperature and high-strength titanium alloy thermal deformation flow stress constitutive equation, and substituting the disc core combined straight line conical surface area, the required pressure for high-temperature plastic deformation is calculated, and then the rotation speed and the pressure holding time are set, and the disc core blank and the disc rim blank are relatively frictionally rotated at high speed to prepare a high-temperature and high-strength double-alloy disc blank.

[0053] The disc core and disc rim high-reliability connection and size accurate control method of the double-titanium alloy disc, according to the load bearing, temperature bearing and structural size characteristics of the engine disc, and according to the strain control principle of titanium alloy plastic deformation, on the basis of the traditional inertial friction welding process, through the special inner and outer conical surface structure and size design of the disc core and the disc rim, then the disc core and the disc rim are relatively frictionally moved at low speed by using the inertial friction welding equipment, the size of the disc core and the disc rim connection part is accurately adjusted and controlled, finally the disc core and the disc rim are relatively frictionally moved at high speed, the solid-state connection is realized through plastic thermal deformation, a high-temperature / high-strength double-alloy disc is prepared, the high-reliability connection and size accurate control of the connection part are realized, the problems of performance weakening of the double-alloy disc connection part and size fluctuation affecting performance uniformity are solved, compared with the ordinary inertial friction welding double-alloy disc preparation method, the method also has the following advantages:

[0054] In step S10, the load bearing, temperature bearing and structural size of the disc are taken as the theoretical basis, a coaxial conical surface is made to divide the disc core part and the disc rim part of the double-alloy disc, and the coaxial conical surface is the disc core combined straight line conical surface of the disc core, that is, the shape and size of the disc core combined straight line conical surface are designed first to accurately determine the position of the disc core and the disc rim connection part of the double-alloy disc, and ensure that the high-temperature / high-strength titanium alloy material plays a role in high-temperature bearing and high-load bearing of the disc;

[0055] In step S20, according to the strain control principle of high-temperature plastic thermal deformation of titanium alloy, a coaxial circular arc line which is in contact with the outer side of the coaxial conical surface and is an arc line is designed, so that the convex shape and size of the disc rim outer circular arc conical surface are designed, the disc core and disc rim joint surface is changed from circular line surface contact to circular arc surface contact, so that the air possibly entering the joint part of the disc core and disc rim is fully discharged, and high-quality connection in the high-temperature plastic deformation range of the disc core and disc rim joint surface is realized.

[0056] In step S40, through the low rotation speed and small upset force setting of the inertia friction welding equipment, the disc core blank and the disc rim blank can be rotated by low rotation friction, the coaxiality of the disc core and the disc rim is automatically adjusted and controlled, the size fluctuation in the circumferential direction of the joint part of the disc core and the disc rim is prevented, and conditions for size accurate control of the joint part are provided.

[0057] In step S50, through high-speed friction rotation of the disc core blank and the disc rim blank, high-temperature plastic deformation of the conical joint surface of the disc core and the disc rim is realized, the inertia friction welding upset pressure is accurately calculated according to the titanium alloy rheological stress constitutive equation and the disc core joint linear conical surface area, and high-quality preparation of the high-temperature / high-strength dual-alloy disc blank is realized by cooperating with the control of the rotation speed and the pressure holding time.

[0058] Therefore, through the special joint surface structure and size design of the disc core and the disc rim, the method can not only realize high reliability of the inertia friction welding plastic deformation connection, but also realize size accurate distribution of the coaxial joint part of the disc core and the disc rim, can meet the high temperature bearing and high load bearing performance requirements of the new generation of aero-engine titanium alloy disc, can prepare a high-temperature / high-strength dual-alloy disc according to the needs of the aero-engine disc, realize high-quality connection and size accurate control of the two kinds of alloy materials of the disc core and the disc rim, and has great popularization and application value in production.

[0059] Optionally, step "S10: disc core joint linear conical surface design" specifically includes the following steps:

[0060] S101: a plan view is designed with the maximum diameter section of the disc, a coaxial circular surface with a diameter of ΦD is drawn to divide the disc core part and the disc rim part, as shown in Figure 1 (a);

[0061] S102: a coaxial conical line passing through the base point is drawn, the coaxial conical line intersects the disc core at both ends, and the conical surface formed by rotating the coaxial conical line for one revolution is a coaxial conical surface, as shown in Figure 1 (b) and Figure 1 (c).

[0062] In this optional solution, as shown in Figure 1(c) as shown, assuming that the coaxial conical surface formed by rotating a coaxial conical line for one revolution has a small end face diameter of ΦD1, a large end face diameter of ΦD2, and a conical surface thickness H between the small end face and the large end face, then: 0.04≤(ΦD2-ΦD1) / H≤0.3, and the structure size limitation of the coaxial conical surface can realize effective connection and control of the angle of the combination surface of the disc core and the disc rim.

[0063] Optionally, the step "S20: disc rim combination circular arc conical surface design" specifically comprises the following steps:

[0064] S201: a plan view is designed with the maximum diameter cross section of the wheel disc, and an offset line intersecting the two end faces of the disc rim is formed by offsetting the coaxial conical line outward by a distance, as shown in Figure 2 (a);

[0065] S202: a coaxial circular arc line passing through the three intersection points is drawn with the two intersection points of the offset line and the two end faces of the disc rim, the intersection point of the disc core axial center position diameter surface and the coaxial circular surface, and the circular arc conical surface formed by rotating the coaxial circular arc line for one revolution is the disc rim combination circular arc conical surface, as shown in Figure 2 (b) and Figure 2 (c).

[0066] In this optional solution, in the step "S20: disc rim combination circular arc conical surface design", the offset line is parallel to the coaxial conical line, and the offset distance X has a value of: 0.1mm≤X≤3mm, and the size limitation of the offset distance can realize effective control of the offset of the combination surface of the disc core and the disc rim.

[0067] In this optional solution, in the step "S20: disc rim combination circular arc conical surface design", assuming that the two intersection points of the offset line and the two end faces of the disc rim are intersection points A and B, and the intersection point of the disc core axial center position diameter surface and the coaxial circular surface is intersection point E; then the coaxial circular arc line is drawn with the positions of points A, B and E, and the circular arc conical surface formed by rotating the coaxial circular arc line for one revolution is the disc rim combination circular arc conical surface.

[0068] Optionally, in the step "S30: disc core and disc rim blank preparation", a corresponding high-strength titanium alloy material is selected according to the service temperature and stress distribution of the disc core, and a corresponding high-temperature titanium alloy material is selected according to the service temperature and stress distribution of the disc rim, and the disc core blank prepared by using the high-strength titanium alloy material and the disc rim blank prepared by using the high-temperature titanium alloy material have structures as shown in Figure 3 (b) and Figure 3 (a).

[0069] Optionally, in the step "S40: low-rotating-speed coaxial adjustment", the disc core blank is installed at the pushing end of the inertia friction welding device, the disc rim blank is installed at the rotating end of the inertia friction welding device, the rotating speed of the inertia friction welding device is set to 5-30 rpm, the top forging pressure is set to 0.5-10 MPa, and the disc core blank and the disc rim blank are relatively frictionally rotated at a low rotating speed. Figure 4 (a) and Figure 4 (b) shown. In this optional scheme, based on previous practice and repeated trial production, the rotating speed of the inertia friction welding device is set to 5-30 rpm, and the top forging pressure is set to 0.5-10 MPa.

[0070] Optionally, in the step "S50: high-rotating-speed connection preparation", based on the hot deformation flow stress constitutive equation of the high-temperature and high-strength titanium alloy, and by substituting the disc core combined linear conical surface area S, the pressure required for the plastic deformation of the disc core blank and the disc rim blank at high temperature is calculated, and the average value of the required pressure is taken as the top forging pressure P of the inertia friction welding device.

[0071] In this optional scheme, in the step "S50: high-rotating-speed connection preparation", based on the friction heat generation principle, the rotating speed is set to 350-450 rpm to achieve effective connection; and according to the alloy temperature reduction time calculation, the pressure holding time is set to ≤20 s, so that the disc core blank and the disc rim blank are frictionally rotated at a high rotating speed (as shown in Figure 5 (a) and Figure 5 (b) shown) to achieve plastic hot deformation connection, and a high-temperature / high-strength dual-alloy disc blank is prepared, as shown in Figure 6 .

[0072] The control method solves the problems of performance difference and size fluctuation of the connection part of the dual-alloy disc, and has been tested, simulated and parts have been prepared in practice, realizing high reliability and size accurate control of the connection part, meeting the high-temperature and high-load requirements of the dual-alloy disc, and the specific implementation is as follows:

[0073] Example 1: The step S10 of the method of the present application is used to design the disc core combined linear conical surface, according to the load bearing, temperature bearing and structure size requirements of a certain turbofan engine disc, as shown in Figure 7(a) shown, the design divides the disc core part and the disc rim part, determines the disc core combined straight taper face small end face diameter, large end face diameter and thickness size; then adopts step S20 to design the disc rim combined circular arc taper face, according to the strain control principle of titanium alloy high temperature plastic hot deformation, offsets the coaxial conical line in step S10 outward by 0.5 mm, determines three circular arc points, forms the disc rim combined circular arc outer taper face; adopts step S30 and step S40 to adjust the low speed coaxiality of the disc core and the disc rim, scales the disc core blank and the disc rim blank designed in step S10 and step S20, respectively adopts IMI834 high temperature titanium alloy and Ti6246 high strength titanium alloy to carry out allowance processing, to respectively manufacture the disc core blank and the disc rim blank, and installs on the inertia friction welding equipment, sets the inertia friction welding speed to 8 revolutions per minute, the upset pressure to 0.8 MPa, makes the disc core blank and the disc rim blank relatively friction rotate at low speed, realizes the automatic adjustment of the coaxiality of the disc core and the disc rim; finally adopts step S50 to carry out the high speed connection preparation of the double alloy disc blank, according to the IMI834 / Ti6246 titanium alloy hot compression rheological stress constitutive equation and the disc core combined straight taper face area, calculates and determines that the inertia friction welding upset pressure is 60 t, the speed is 400 revolutions per minute, the pressure maintaining time is 20 s, makes the disc core blank and the disc rim blank friction rotate at high speed, realizes the plastic hot deformation connection, prepares the IMI834 / Ti6246 double alloy disc blank, such as Figure 7 (b) shown.

[0074] Example two: adopts step S10 of the method of the present application to design the disc core combined straight taper face, according to the load bearing, temperature bearing and structure size requirements of a certain turbo-shaft engine disc, such as Figure 8(a) shown, the design divides the disc core part and the disc rim part, determines the disc core combined straight line taper face small end face diameter, large end face diameter and thickness size;Then step S20 is used to design the disc rim combined circular arc taper face, according to the strain control principle of titanium alloy high temperature plastic hot deformation, the coaxial conical line in step S10 is offset outward by 0.3mm, three points of circular arc are determined, and the disc rim combined circular arc taper face is formed;Step S30 and step S40 are used to adjust the low speed coaxiality of the disc core and the disc rim, the disc core blank and the disc rim blank designed in step S10 and step S20 are scaled, and IMI834 high temperature titanium alloy and Ti6246 high strength titanium alloy are used for allowance machining, respectively, to manufacture the disc core blank and the disc rim blank, and install them on the inertia friction welding equipment, set the inertia friction welding speed to 10 revolutions per minute and the upset pressure to 1MPa, so that the disc core blank and the disc rim blank are relatively frictionally rotated at low speed, and the coaxiality of the disc core and the disc rim is automatically adjusted;Finally, step S50 is used to prepare the high speed connection of the double alloy disc blank, according to the IMI834 / Ti6246 titanium alloy hot compression rheological stress constitutive equation and the disc core combined straight line taper face area, the inertia friction welding upset pressure is calculated and determined to be 80t, the speed is 450 revolutions per minute, and the pressure holding time is 20s, so that the disc core blank and the disc rim blank are frictionally rotated at high speed, the plastic hot deformation connection is realized, and the IMI834 / Ti6246 double alloy impeller blank is prepared, as shown in Figure 8 (b) shown.

[0075] The above only describes the preferred embodiments of the present application and is not used to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A method for high reliability connection and dimensional accuracy control of a disc core to a rim of a dual titanium alloy disc, characterized in that, It comprises the following steps: Disc core combined linear taper design: based on the bearing, temperature and structural size of the disc, the coaxial circular conical surface is drawn to divide the disc core and disc rim parts, and the coaxial circular conical surface is the disc core combined linear taper; Disc rim combined circular arc taper design: according to the strain control principle of high temperature plastic thermal deformation of titanium alloy, the coaxial circular arc line which contacts the coaxial circular conical surface and is a circular arc line is drawn, and the conical arc surface formed by the coaxial circular arc line rotating around the coaxial circular conical surface is the disc rim combined circular arc taper; Disc core and disc rim blank preparation: high-strength titanium alloy material is selected to prepare disc core blank with disc core combined linear taper outer taper surface, and high-temperature titanium alloy material is selected to prepare disc rim blank with disc rim combined circular arc taper inner taper surface; Low-speed coaxiality adjustment: the disc core blank and the disc rim blank are respectively installed on the inertia friction welding equipment, and the rotation speed and the upsetting pressure of the inertia friction welding are set, then the disc core blank and the disc rim blank are relatively rotated at low speed; High-speed connection preparation: based on the high-temperature and high-strength titanium alloy thermal deformation flow stress constitutive equation, and substituting the disc core combined linear taper area, the pressure required for high-temperature plastic deformation is calculated, and then the disc core blank and the disc rim blank are rotated at high speed to prepare high-temperature and high-strength double titanium alloy disc blank.

2. The method of claim 1, wherein the method is characterized by: The step "disc core combined linear taper design" specifically comprises the following steps: A plan view is designed based on the maximum diameter section of the disc, and a coaxial circular surface with a diameter of ΦD is drawn to divide the disc core part and the disc rim part; A coaxial circular conical line passing through the intersection point of the coaxial circular surface and the disc core axial center position radial surface is drawn, and the coaxial circular conical line intersects with the two ends of the disc core, and the conical surface formed by the coaxial circular conical line rotating around the coaxial circular surface is the coaxial circular conical surface.

3. The disc core and disc rim high-reliability connection and size accurate control method of the double titanium alloy disc according to claim 2, wherein the conical surface small end surface diameter of the coaxial circular conical surface formed by the coaxial circular conical line rotating around the coaxial circular surface is ΦD1, the conical surface large end surface diameter is ΦD2, and the conical surface thickness between the conical surface small end surface and the conical surface large end surface is H, and 0.04≤(ΦD2-ΦD1) / H≤0.

3. The step "disc rim combined circular arc taper design" specifically comprises the following steps:

4. The method of claim 2, wherein the method is characterized by: A plan view is designed based on the maximum diameter section of the disc, and a coaxial circular conical line is offset outward to form an offset line which intersects with the two end surfaces of the disc rim; A coaxial circular arc line passing through the three intersection points of the offset line and the two intersection points of the disc rim two end surfaces, and the intersection point of the disc core axial center position radial surface and the coaxial circular surface is drawn, and the conical arc surface formed by the coaxial circular arc line rotating around the coaxial circular surface is the disc rim combined circular arc taper.

5. The disc core and disc rim high-reliability connection and size accurate control method of the double titanium alloy disc according to claim 4, wherein in the step "disc rim combined circular arc taper design", the offset line is parallel to the coaxial circular conical line, and the offset distance X is 0.1mm≤X≤3mm.

6. The disc core and disc rim high-reliability connection and size accurate control method of the double titanium alloy disc according to claim 4, wherein ​ ​ In the step "Design of the circular arc conical surface combined with the rim", the two intersection points of the offset line and the two end surfaces of the rim are denoted as intersection points A and B, and the intersection point of the axial center position radial surface of the disc core and the coaxial circumferential surface is denoted as intersection point E; Then, the coaxial circular arc line is drawn through the positions of the three points A, B and E.

7. The method according to claim 1, wherein the disc core and the rim are made of high-strength titanium alloy and high-temperature titanium alloy respectively according to the service temperature and stress distribution of the disc core and the rim.

8. The method according to claim 1, wherein the low-rotation coaxiality adjustment is performed by installing the disc core blank on the push end of the inertia friction welding device, installing the rim blank on the rotating end of the inertia friction welding device, setting the rotation speed of the inertia friction welding device to 5-30 rpm and the upset pressure to 0.5-10 MPa, and making the disc core blank and the rim blank rotate at a low rotation speed.

9. The method according to claim 1, wherein the high-rotation connection preparation is performed by calculating the pressure required for the plastic deformation of the disc core blank and the rim blank based on the thermal deformation flow stress constitutive equation of the high-temperature and high-strength titanium alloy and substituting the disc core combined linear conical surface area S, and taking the average value of the required pressure as the inertia friction welding upset pressure P.

10. The method according to claim 9, wherein the high-rotation connection preparation is performed by setting the rotation speed to 350-450 rpm and the pressure holding time to ≤20 s, making the disc core blank and the rim blank rotate at a high rotation speed, realizing plastic thermal deformation connection, and preparing a high-temperature / high-strength dual-alloy disc blank. ​ ​ ​ ​

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