Method and equipment for testing interlayer bonding strength of titanium stainless steel composite rod

Abstract

The invention discloses a method and equipment for testing interlayer bonding strength of a titanium stainless steel composite rod. The test method comprises the following steps: 1) cutting and sampling a titanium stainless steel composite rod, and turning to obtain a required sample; (2) nesting and mounting the sample and the testing fixture; 3) placing the sample and the gauge on a universal testing machine, applying a vertically downward pressure to the sample by using the universal testing machine, pressing the titanium clad material of the sample to be separated from the stainless steel base material, and recording the pressure F applied by the universal testing machine; and 4) calculating the shear strength of the titanium clad material and the stainless steel base material according to the pressure F and the area of the sheared surface of the sample. According to the invention, the shear acting force only acts on the titanium clad layer through the assembly limit between the sample and the gauge, so that the bonding layer between the titanium clad layer and the stainless steel base layer generates shear failure, and the interlayer bonding strength of the titanium stainless steel composite rod is accurately measured; the sample and the detection tool are convenient to process, low in processing cost and short in detection period, and can be popularized to industrial use.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of strength detection, in particular to a titanium stainless steel composite rod interlayer bonding strength testing method and equipment. BACKGROUND

[0002] Titanium stainless steel composite rod mainly refers to a composite rod-shaped material coated with a layer of titanium of a certain thickness on the surface of a stainless steel rod, which is generally produced by explosive welding process. It is widely used in energy, chemical industry and aerospace fields due to its mechanical properties of stainless steel material and corrosion resistance of titanium layer. The base layer and the composite layer of the titanium stainless steel composite rod are metallurgically combined, and the two metals are in 100% fusion state, with extremely high bonding strength, generally not less than 140 MPa.

[0003] The interlayer bonding strength of the titanium stainless steel composite rod refers to the bonding strength of titanium and stainless steel after explosive compounding. The material with low bonding strength is prone to interlayer separation during use, which can seriously reduce the stiffness and strength of the composite material. Therefore, bonding strength is a problem that must be considered in the design and production of titanium stainless steel composite rod materials. Testing and evaluation of bonding strength are very important issues for reasonable design of titanium stainless steel rod composite materials, expansion of their application range and ensuring their safety in use.

[0004] For the bonding strength detection of metal composite materials, the current national standard "Test Methods for Mechanical and Technological Properties of Composite Steel Plates" (GB / T6396-2008) only recommends a method for plate-shaped composite materials, and there is no specific detection method for rod-shaped composite metal materials. Composite rods or pipes cannot be processed into the test samples recommended by the national standard. Although the national military standard provides a method for detecting the bonding strength of titanium stainless steel composite rods, the method has high requirements for sample processing, and the sample size is long, the test equipment is complex to clamp, the detection cost is high, and the detection period is long. Chinese invention patent application CN116124691A discloses a layered nested metal pipe interlayer bonding strength testing device and testing method, which is only applicable to nested combined composite pipes with low bonding strength. For high-strength metallurgical combined pipes, the base material and auxiliary material cannot be separated by the sample involved in the test method. Chinese invention patent application CN117825162A discloses a titanium-copper composite rod bonding strength detection method and equipment, but the test method involves tensile shear, which also cannot realize the shear separation of high-strength metallurgical combined rods / pipes. In addition, the manufacturing and use of the testing tool involved in the patent are relatively complex, which is not conducive to rapid testing.

[0005] Therefore, it is necessary to provide a fast, accurate and efficient titanium stainless steel composite rod interlayer bonding strength test method. SUMMARY

[0006] To solve the problems in the prior art, the purpose of the present application is to provide a fast, accurate and efficient titanium stainless steel composite rod shear strength test method.

[0007] To achieve the above purposes and achieve the above technical effects, the technical scheme adopted by the present application is as follows:

[0008] A titanium stainless steel composite rod interlayer bonding strength test method, comprising the following steps:

[0009] 1) Sample preparation: cutting and sampling the titanium stainless steel composite rod, and obtaining the required sample after turning; wherein the titanium stainless steel composite rod comprises a stainless steel base material and a titanium cladding material arranged in order from inside to outside;

[0010] 2) Sample installation: nest installation of the sample and the gauge;

[0011] 3) Shearing: placing the sample and the gauge on the universal testing machine, applying a vertical downward pressure to the stainless steel base material of the sample by the universal testing machine, pressing the titanium cladding material and the stainless steel base material of the sample to separate, and recording the pressure F applied by the universal testing machine;

[0012] 4) Calculation: calculating the interlayer bonding strength of the titanium cladding material and the stainless steel base material according to the pressure F and the area of the shear surface of the sample.

[0013] Further, in step 1), the sample of the titanium stainless steel composite rod is:

[0014] The length of the titanium stainless steel composite rod is L A , the outer diameter is D, and the outer diameter of the stainless steel base material is d;

[0015] The outer diameter of one end of the titanium stainless steel composite rod sample after turning is d1, and the length after turning is L1; the outer diameter of the other end of the titanium stainless steel composite rod sample after turning is d2 < d1, and the length after turning is L2; the connection between the two ends of the titanium stainless steel composite rod sample is reserved for the bonding section of the titanium cladding material and the stainless steel base material, and the length of the bonding section is L0 = L A -L1-L2>0, and the outer diameter of the bonding section after turning is D1.

[0016] Further, d1 = d-0.5~0.6mm; L1=8~14mm; d2=d-1.5~1.6mm; L2=6~14mm; L0=1~3mm, preferably 2mm; D1=D-0.9~1mm; L A =15~30mm.

[0017] Further, in step 1), the titanium stainless steel composite rod sample obtained is:

[0018] The length of the titanium stainless steel composite rod is L B , the outer diameter is D, and the outer diameter of the stainless steel base material is d.

[0019] The outer diameter of the titanium stainless steel composite rod sample after turning at both ends is d1, and the length after turning is L1; the outer diameter of the titanium stainless steel composite rod sample after turning in the middle is d2 < d1, and the length after turning is L2; the middle part of the titanium stainless steel composite rod sample and the connecting part of the two ends are reserved respectively, and the combined segment of the titanium cladding material and the stainless steel base material is reserved, and the length of the combined segment is L0 = (L B -2L1-L2) / 2>0, and the outer diameter of the combined segment after turning is D1.

[0020] Further, d1 = d-0.5~0.6mm; L1=8~18mm; d2=d-1.5~1.6mm; L2=5~20mm, preferably L2=10~18mm; L0=1~3mm, preferably 2mm; D1=D-0.9~1mm; L B =25~60mm.

[0021] Further, in step 2), the testing tool is a tubular bearing platform, the inner hole diameter is d3>d, the inner hole depth is L3, the wall thickness is t, a limiting step is turned at the top of the bearing platform inner hole for titanium cladding limiting, the diameter of the limiting step is d4>D1, and the depth is L4; d3-d>d4-D1.

[0022] Further, the bearing platform inner hole diameter d3=d+1.4~1.6mm, the bearing platform inner hole depth L3≥L1+10mm, the bearing platform wall thickness t≥12mm, the bearing platform limiting step diameter d4=D1+0.8~1mm (or d4=D-0~0.1mm), and the bearing platform limiting step depth L4 satisfies 0.5mm≤L4≤L0.

[0023] Further, the bearing platform is made of 45# steel or 40Cr material.

[0024] Further, the formula for calculating the interlayer bonding strength is as formula (1):

[0025] τ=F / A (1)

[0026] In the formula, τ is the shear strength, F is the vertical downward force of the sample on the universal testing machine, and A is the theoretical calculation of the contact area between the titanium cladding material and the stainless steel base material; wherein, A=π×L0×d.

[0027] In the second aspect, the present application discloses a kind of titanium stainless steel composite rod interlayer bonding strength test equipment, including universal testing machine and above-mentioned testing tool.

[0028] Compared with the prior art, the test method provided by the application has the following beneficial technical effects:

[0029] 1) The annular sample and the annular testing tool are designed, the assembly limit between the sample and the testing tool and the ingenious size design thereof are used, the shearing force is only and always applied to the titanium clad material, the bonding layer between the titanium clad layer and the stainless steel base layer is caused to fail in shearing, interference is reduced, and the interlayer bonding strength of the titanium stainless steel clad rod can be accurately measured.

[0030] 2) The sample and the testing tool have low processing cost and short processing cycle, the testing tool can be repeatedly used, the interlayer bonding strength of the titanium stainless steel clad rod can be effectively detected, the test result is high in accuracy, the detection cycle is short, the cost is low, the testing tool can be repeatedly used, and the application is suitable for industrial popularization and use.

[0031] 3) The shearing area is small, the required test force is small, the maximum test force requirement of the universal testing machine is reduced, and the problem of insufficient test force in the prior art is overcome. DETAILED DESCRIPTION

[0032] Figure 1 It is a schematic diagram of the test sample of the application.

[0033] Figure 2 It is a schematic diagram of the testing tool of the application.

[0034] Figure 3 It is a schematic diagram of the test test of the application.

[0035] Figure 4 It is a schematic diagram of the test test of the application. Figure 3 It is a schematic diagram of the test test of the application.

[0036] Figure 5 It is a test result diagram of embodiment 1 of the application.

[0037] In the diagram, 1 is a stainless steel base material, 2 is a titanium clad material, 3 is a bearing platform, 4 is a limiting step, and 5 is a bonding section. DETAILED DESCRIPTION

[0038] The application will be described in detail below, so that the advantages and features of the application can be more easily understood by those skilled in the art, and the protection scope of the application can be more clearly and explicitly defined.

[0039] The following gives a brief summary of one or more aspects to provide a basic understanding of these aspects. This summary is not an extensive overview of all contemplated aspects, and is neither intended to identify key or critical elements of all aspects nor to delineate the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description that is presented later.

[0040] Embodiment one;

[0041] The embodiment provides a titanium stainless steel composite rod interlayer bonding strength test method, which comprises the following steps:

[0042] 1) sample preparation: cutting and sampling the titanium stainless steel composite rod, and obtaining a required sample after turning processing; wherein the titanium stainless steel composite rod comprises a stainless steel base material and a titanium cladding material arranged in sequence from inside to outside;

[0043] 2) sample installation: embedding and installing the sample and a testing tool;

[0044] 3) compression and shearing: placing the sample and the testing tool on a universal testing machine, applying a vertical downward pressure on the stainless steel base material of the sample by using the universal testing machine, and pressing the titanium cladding material and the stainless steel base material of the sample to separate, and recording the pressure F applied by the universal testing machine;

[0045] 4) calculation: calculating the interlayer bonding strength of the titanium cladding material and the stainless steel base material according to the pressure F and the area of the shearing surface of the sample.

[0046] Further, in step 1), the sample of the titanium stainless steel composite rod obtained is:

[0047] The length of the titanium stainless steel composite rod is L A , the outer diameter is D, the outer diameter of the stainless steel base material is d;

[0048] The outer diameter of one end of the titanium stainless steel composite rod sample after turning is d1, and the length after turning is L1; the outer diameter of the other end of the titanium stainless steel composite rod sample after turning is d2 A < L1-L2> 0, and the outer diameter of the combined section after turning is D1.

[0049] Further, in step 2), the testing tool is a tubular bearing platform, the inner hole diameter is d3 > d, the inner hole depth is L3, the wall thickness is t, a limiting step is turned at the top of the inner hole of the bearing platform, which is used for limiting the titanium composite layer, the diameter of the limiting step is d4 > D1, the depth is L4, d3-d > d4-D1; the outer diameter of the bearing platform is D2, D2 = d3+2t. d3-d > d4-D1 means that the bonding interface between the titanium composite layer and the stainless steel base material is always in the inner hole of the bearing platform during the test. In addition, it is also necessary to ensure that the combined section 5 is always supported on the limiting step, and D1 > d4 / 2+d3 / 2, that is, when one side of the combined section 5 is completely supported on the limiting step on the side, the other side of the combined section 5 can also be supported on the limiting step on the other side.

[0050] More specifically, d1 = d - 0.5 ~ 0.6 mm, L1 = 8 ~ 14 mm; d2 = d - 1.5 ~ 1.6 mm, L2 = 5 ~ 20 mm; L0 = 1 ~ 3 mm, D1 = D - 0.9 ~ 1 mm, and thus L A = 15 ~ 30 mm.

[0051] More specifically, the diameter d3 of the inner hole of the bearing platform is d + 1.4 ~ 1.6 mm, the depth L3 of the inner hole of the bearing platform is greater than or equal to L1 + 10 mm, the wall thickness t of the bearing platform is greater than or equal to 12 mm, the diameter d4 of the limiting step of the bearing platform is D1 + 0.8 ~ 1 mm or d4 = D - 0 ~ 0.1 mm, and the depth L4 of the limiting step of the bearing platform satisfies 0.5 mm ≤ L4 ≤ L0, and preferably L4 = L0.

[0052] The designed testing tool is a bearing platform, and the main function of the bearing platform is to make the reaction force F' of the pressure F applied by the universal testing machine on the test sample during the test of the titanium stainless steel composite rod always act as a shear force on the titanium ring (titanium clad material).

[0053] The design points of the embodiment are as follows: by designing the assembly gap between the test sample and the bearing platform of the testing tool, the accurate installation of the test sample can be ensured, and at the same time, the composite interface of the test sample is always in the inner hole of the bearing platform and does not contact the bearing platform, so as to ensure that the reaction force of the universal testing machine on the test sample during the test only acts on the titanium composite layer. Through stress analysis, it can be known that during the test, the test sample is subjected to the vertical downward force F of the universal testing machine, the tool base is subjected to the vertical downward force G of the test sample and the downward force F of the universal testing machine, and the vertical upward reaction force of the tool base acting on the test sample through the titanium composite layer is equal to F + G. Since the weight G of the test sample is much smaller than F, the weight G of the test sample can be ignored. Thus, the vertical upward force on the composite interface of the test sample causes the shear failure of the composite interface.

[0054] Further, in step 4), the calculation formula of the interlayer bonding strength is as formula (1):

[0055] τ = F / A (1)

[0056] In the formula, τ is the shear strength, F is the vertical downward force of the test sample subjected to the universal testing machine, and A is the theoretical calculation of the contact area between the titanium clad material and the stainless steel base material; wherein A = π × L0 × d.

[0057] The embodiment provides a standard test sample, and each test sample is tested once. The final test result can be obtained by taking the average value after testing a plurality of test samples.

[0058] Embodiment two;

[0059] The embodiment provides another test method for the shear strength of a titanium stainless steel composite rod, and the difference from the first embodiment is the size of the test sample.

[0060] The length of the titanium stainless steel composite rod is L B , the outer diameter of the stainless steel base material is d;

[0061] The outer diameter of the titanium stainless steel composite rod sample after turning at both ends is d1, and the turned length is L1; the outer diameter of the titanium stainless steel composite rod sample after turning at the middle part is d2 < d1, and the turned length is L2; the combined segments of the titanium cladding material and the stainless steel base material are reserved at the connection between the middle part and both ends of the titanium stainless steel composite rod sample, and the length of the combined segment is L0 = (L B -2L1-L2) / 2>0, and the outer diameter of the combined segment after turning is D1.

[0062] More specifically, d1 = d-0.5~0.6mm; L1 = 8~18mm; d2 = d-1.5~1.6mm; L2 = 5~20mm, preferably L2 = 10~18mm; L0 = 1~3mm, preferably 2mm; D1 = D-0.9~1mm; and thus L B = 25~60mm.

[0063] After the sample and the testing tool are combined and placed horizontally under the pressure head of the universal testing machine, the universal testing machine is started, the force-displacement curve during the experiment is recorded by the computer, and the force F when the titanium layer is compressed to the failure of the combination with the stainless steel layer during the experiment is recorded. After the experiment is completed, the sample direction is reversed, and another experiment can be performed, i.e., a single sample can be tested twice, and the results of the two tests do not affect each other.

[0064] The present embodiment provides a standard sample, each of which can be tested twice. However, the final test result can be obtained by taking the average after testing one sample. Embodiment two is more convenient and has more test times than embodiment one.

[0065] The reasons for using the sample involved in the present application are: ① The present sample solves the problem that only plate-shaped composite materials can be tested in the existing national standard recommended test method, and rod-shaped materials cannot be processed according to the national standard recommended method; ② The present sample (embodiment two) is simple and easy to process, and the processing time of a single sample in the practice process is about 40 minutes, which is much lower than the sample form in the prior art, the processing efficiency is high, and the length of the present sample can be as short as 15mm (embodiment one, single shear), which can effectively save the raw materials of the composite rod and reduce the cost; ③ The present sample only needs to process a simple bearing cap tool, and does not need to customize an additional clamp, which is low in cost; ④ When the present sample is used for interlayer bonding strength test, the shear area is small, the required test force is small, the maximum test force requirement of the universal testing machine is not high, and the problem of insufficient test force in the existing method for high-strength metallurgical combined composite pipe is solved. Specific embodiment 1;

[0067] Taking a certain energy engineering of a titanium stainless steel composite rod (material TA1+S31603, titanium layer thickness 4mm, stainless steel diameter 52mm) as an example, the detection method of the interlayer bonding strength of the titanium cladding material and the stainless steel base material comprises the following steps:

[0068] 1) sample preparation

[0069] The titanium stainless steel composite rod with L=40mm is intercepted, the outer circle of the titanium stainless steel composite rod is turned, the titanium stainless steel composite rod is first turned to 59mm as a whole, then the outer diameter of the titanium stainless steel composite rod within the length range of 10mm at both ends is turned to 51.5mm, and finally the outer circle of the titanium stainless steel composite rod in the middle is turned to 50.5mm, and the length of 2mm of the titanium cladding material and the stainless steel base material at both ends of the composite rod is reserved as a bonding segment; that is, d1=51.5mm, L1=10mm, d2=50.5mm, L0=2mm, L1=18mm, D1=59mm;

[0070] 2) sample installation

[0071] The sample and the testing tool are nested and installed, the sample size is checked, and the titanium cladding material of the sample is in a shearing position;

[0072] The testing tool is made of 45# round steel. The outer diameter is 80mm, and the inner hole diameter is 53.5mm. In order to ensure that the shearing force of the testing tool on the sample is only applied to the titanium layer when the sample is pressed, a step is turned at one end of the inner hole to limit the sample, the step diameter is 60mm, and the depth is 2mm; that is, d3=53.5mm, t=(80mm-53.5mm) / 2=13.25mm, d4=60mm, L4=L0=2mm;

[0073] 3) pressure shearing

[0074] The product obtained in step 2) and the testing tool are placed horizontally under the pressure head of the universal testing machine, a vertical downward pressure is applied to the sample by the universal testing machine, the titanium cladding material and the stainless steel base material of the sample are pressed to failure, the pressure F applied by the universal testing machine is recorded, and the interlayer bonding strength of the titanium cladding material and the stainless steel base material is calculated according to the pressure F and the area of the shearing surface of the sample; the two end bonding areas of a single sample can be subjected to pressure shearing test respectively, and the test results do not affect each other;

[0075] 4) calculation

[0076] The interlayer bonding strength of the titanium cladding material and the stainless steel base material is calculated according to the pressure F and the area of the shearing surface of the sample, τ=F / A.

[0077] The parts or structures not specifically described in the present application can adopt the prior art or existing products, which will not be described here.

[0078] The test results of the embodiment are shown in Table 1 and Figure 4 According toFigure 4 It can be seen that at the beginning of loading, the deformation test value is large, indicating that the sample is in close contact with the testing tool and the universal testing machine; then, the force gradually increases, and when the force reaches 73.84 kN, the sample bonding layer is damaged, and the force decreases. According to the calculation, the interlayer bonding strength τ of the titanium stainless steel composite rod can reach 238.0 MPa. In Table 1, B is the circumference of the sheared area (Π•d), W is the thickness of the sheared circle, that is, L0, W=1.9 mm is the thickness data of the measured bonding section, and the data is used as the standard in calculation, so it does not affect the accuracy of the test.

[0079] Table 1 Test results

[0080]

[0081] The test method of the present application can be used not only to detect the interlayer bonding strength of the titanium stainless steel composite rod, but also to detect rod-shaped metal composite materials with similar structures, such as stainless steel composite rods, nickel steel composite rods, titanium steel composite rods, titanium copper composite rods, etc.

[0082] The above examples are only used to illustrate the technical solutions of the present application and do not constitute a limitation on the protection scope of the present application. For ordinary skilled persons in the art, various equivalent replacements, transformations, improvements or changes made based on the disclosed content without departing from the technical essence and spirit of the present application shall be considered to belong to the scope of protection required by the present application.

Claims

1. A method for testing the interlayer bond strength of a titanium-stainless steel composite rod, characterized by comprising the following steps: 1) Sample preparation: The titanium-stainless steel composite rod is cut and sampled, and then machined to obtain the required specimen; among which, The titanium-stainless steel composite rod comprises a stainless steel substrate and a titanium cladding material arranged sequentially from the inside to the outside. 2) Sample mounting: The sample and the fixture are nested and installed; 3) Compression and shear: Place the specimen and fixture on the universal testing machine, and apply a vertical downward pressure to the stainless steel substrate of the specimen using the universal testing machine to press the titanium coating of the specimen to separate from the stainless steel substrate. Record the pressure applied by the universal testing machine. 4) Calculation: Calculate the interlayer bond strength between the titanium cladding and the stainless steel substrate based on the pressure and the area of ​​the shear surface of the sample.

2. The method for testing the interlayer bond strength of titanium-stainless steel composite rods according to claim 1, characterized in that: In 1), the sample of the titanium-stainless steel composite rod is: The length of the titanium-stainless steel composite rod is L. A The outer diameter is D, and the outer diameter of the stainless steel substrate is d; The outer diameter of one end of the titanium stainless steel composite bar sample after being turned is d1, and the turned length is L1; the outer diameter of the other end of the titanium stainless steel composite bar sample after being turned is d2 < d1, and the turned length is L2; a bonding section of the titanium clad material and the stainless steel substrate is reserved at the connection of both ends of the titanium stainless steel composite bar sample, and the length of the bonding section is L0 = L A - L1 - L2 > 0, and the outer diameter of the bonding section after being turned is D1.

3. The method for testing the interlayer bonding strength of titanium-stainless steel composite rods according to claim 2, characterized in that: the outer diameter d1 of one end of the titanium-stainless steel composite rod sample after machining is d-0.5~0.6mm, and the machining length L1 is 8~14mm; the outer diameter d2 of the other end after machining is d-1.5~1.6mm, and the machining length L2 is 6~14mm; the length of the joint section L0 is 1~3mm, and the outer diameter D1 of the joint section after machining is D-0.9~1mm.

4. The method for testing the interlayer bond strength of titanium-stainless steel composite rods according to claim 1, characterized in that: In step 1), the sample of the obtained titanium-stainless steel composite rod is: The length of the titanium-stainless steel composite rod is L. B The outer diameter is D, and the outer diameter of the stainless steel substrate is d; The outer diameter of the titanium stainless steel composite rod specimen after turning at both ends is d1, and the turned length is L1; the outer diameter of the titanium stainless steel composite rod specimen after turning in the middle is d2 < d1, and the turned length is L2; the bonding sections of the titanium clad material and the stainless steel substrate are reserved at the connections between the middle and both ends of the titanium stainless steel composite rod specimen, and the length of the bonding section is L0 = (L B - 2L1 - L2) / 2 > 0, and the outer diameter of the bonding section after turning is D1.

5. The method for testing the interlayer bonding strength of titanium-stainless steel composite rods according to claim 4, characterized in that: the outer diameter d1 of both ends of the titanium-stainless steel composite rod sample after machining is d-0.5~0.6mm, and the machining length L1 is 8~18mm; the outer diameter d2 of the middle part after machining is d-1.5~1.6mm, and the machining length L2 is 5~20mm; the length of the joint section L0 is 1~3mm, and the outer diameter D1 of the joint section after machining is D-0.9~1mm.

6. The method for testing the interlayer bond strength of titanium-stainless steel composite rods according to any one of claims 1-5, characterized in that: in 2), the fixture is a tubular support with an inner hole diameter of d3>d, an inner hole depth of L3, and a wall thickness of t, and a limiting step is machined at the top of the inner hole of the support, the limiting step having a diameter of d4>D1 and a depth of L4; d3-d>d4-D1.

7. The method for testing the interlayer bond strength of titanium-stainless steel composite bars according to claim 6, characterized in that: the inner diameter of the bearing platform is d3=d+1.4~1.6mm, the inner depth of the bearing platform is L3≥L1+10mm, the wall thickness of the bearing platform is t≥12mm, and the diameter of the bearing platform limiting step is d4=D1+0.8~1mm, 0.5mm≤L4≤L0.

8. The method for testing the interlayer bond strength of titanium-stainless steel composite bars according to claim 7, characterized in that: the support platform is made of 45# steel or 40Cr material.

9. The method for testing the interlayer bond strength of titanium-stainless steel composite rods according to claim 6, characterized in that: the calculation formula for the interlayer bond strength is as shown in formula (1): τ=F / A(1) In the formula, τ is the shear strength, F is the downward force exerted on the specimen by the universal testing machine, and A is the theoretically calculated contact area between the titanium cladding and the stainless steel substrate; where, A = π × L0 × d.

10. A device for testing the interlayer bond strength of titanium-stainless steel composite rods, characterized in that: Includes a universal testing machine and the inspection fixture as described in claim 6.

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