Design method and use method of welding material for Mo-containing high-temperature titanium alloy

Abstract

The present invention relates to the field of welding technology, and in particular to a design method and a use method of a welding material for a Mo-containing high-temperature titanium alloy. The design method comprises: A1) designing a chemical formula of a welding material for a Mo-containing high-temperature titanium alloy as shown in formula (1); in the welding material, the mass content of Ti is 20% to 50%, the mass content of Ag is 1% to 2%, and the mass content of Gd is 0 to 0.7%; and the mass content of Mo in the Mo-containing high-temperature titanium alloy and the ratio of the mass content of Mo in the welding material to the mass content of X are limited; B1) by calculation, the a value and the c value are obtained, and then the welding material for the Mo-containing high-temperature titanium alloy is obtained. The welding material obtained by the design method provided by the present invention is used to weld the Mo-containing high-temperature titanium alloy, and the joint strength is better.

Description

Technical Field

[0001] The invention relates to the technical field of welding, and in particular to a design method and a use method of a welding material for a Mo-containing high-temperature titanium alloy. Background Art

[0002] Titanium alloys are mainly used to manufacture disks, blades and isolation devices for fans and compressors of engines in the aviation and other fields, as well as engine air intake casings, air collectors and other parts. Conventional titanium alloys such as TC4 alloys have a working range of 300 to 350°C, and heat-resistant titanium alloys can generally work in the temperature range of 500 to 550°C, and can even work normally at 600°C. Typical high-temperature titanium alloys (also called heat-resistant titanium alloys) include Ti-8Al-1Mo-1V (US Ti-811), Ti-6Al-2Zr-1Mo-1V (Russian BT-20), Ti-6Al-2Sn-4Zr-2Mo (US Ti-6242) and Ti-5.5Al-3.5Sn-3Zr-1Nb-0.3Mo-0.3Si (UK IMI-829). The composition characteristics are that it contains a variety of α-phase stabilizing elements such as aluminum, tin, zirconium, and a small amount of β-phase stabilizing elements such as molybdenum and niobium; its aluminum equivalent is almost 7% to 8% to ensure excellent thermal stability. Heat-resistant titanium alloys are mainly used to manufacture disks, blades, guides, spacers, intake casings and other parts in gas engines.

[0003] Public information on welding technology mainly involves solders and process methods for conventional titanium materials, such as: Patent CN106271213A proposes a titanium-zirconium-copper-nickel based solder for titanium alloy brazing, whose chemical composition and weight percentage are: Zr 10.0-45.0, Cu 10.0-20.0, Ni 10.0-20.0, Re 1.0-2.0, Ti balance. The solder has good wettability and a low melting point, and is suitable for the connection of titanium alloys. Patent CN103143802A discloses a vacuum brazing method for pre-coating titanium alloy and aluminum alloy solder, which prevents the reaction of titanium with active gas by placing the part to be welded of the titanium alloy plate in a solder pool for a period of time, ensuring the smooth progress of the wetting and spreading process, which is conducive to improving the quality of the brazed joint. However, unlike conventional titanium alloys such as TC4 alloys and pure titanium materials, high-temperature titanium alloys have a wide variety of chemical elements and relatively complex chemical compositions, such as the Mo element with a low diffusion coefficient, and a relatively high Al content. Therefore, the welding technology of high-temperature titanium alloys still has technical bottlenecks such as severe brittle joint tendency and insufficient strength caused by the segregation of elements such as Nb and Mo, and there is a lack of suitable welding materials and corresponding process methods. Summary of the invention

[0004] In view of this, the technical problem to be solved by the present invention is a design method and a use method of a welding material for Mo-containing high-temperature titanium alloy. The welding material obtained by the design method provided by the present invention is used to weld the Mo-containing high-temperature titanium alloy, and the joint strength is better.

[0005] The present invention provides a method for designing a welding material for a Mo-containing high-temperature titanium alloy, comprising the following steps:

[0006] A1) The chemical formula of the welding material for Mo-containing high-temperature titanium alloy is shown in formula (1);

[0007] (a) Ti-(b) Zr-(c) X Formula (1);

[0008] In formula (1), a represents the mass content of Ti in the welding material; b represents the mass content of Zr in the welding material, b=30%; c represents the mass content of X in the welding material;

[0009] X is at least one selected from the group consisting of Mo, Sn, Ag and Gd;

[0010] In the welding material, the mass content of Ti is 20% to 50%, the mass content of Ag is 1% to 2%, and the mass content of Gd is 0 to 0.7%;

[0011] When the mass content of Mo in the Mo-containing high-temperature titanium alloy is not higher than 3.0%, the mass content of Mo in the welding material accounts for 20% of the mass content of X; when the mass content of Mo in the Mo-containing high-temperature titanium alloy is 3.0% to 5.0%, excluding 3.0%, the mass content of Mo in the welding material accounts for 30% of the mass content of X; when the mass content of Mo in the Mo-containing high-temperature titanium alloy is 5.0% to 8.0%, excluding 5.0%, the mass content of Mo in the welding material accounts for 35% of the mass content of X; when the mass content of Mo in the high-temperature titanium alloy is 8.0% to 10%, excluding 8.0%, the mass content of Mo in the welding material accounts for 40% of the mass content of X;

[0012] B1) By calculation, the a value and c value are obtained, and then the welding material for Mo-containing high-temperature titanium alloy is obtained.

[0013] Preferably, the Mo-containing high-temperature titanium alloy includes Ti-6Al-2.5Mo-2Cr-0.3Si-0.5Fe, Ti-6.5Al-3.3Mo-1.5Zr-0.25Si or Ti-6Al-2Sn-4Zr-6Mo, Ti-6Al-2.9Mo-2Cr-0.3Si-0.5Fe, Ti-5.5Al-3.5Sn-3Zr-1Nb-0.3Mo-0.3Si or Ti-6Al-5Sn-5Zr-8Mo.

[0014] The present invention also provides a method for welding a Mo-containing high-temperature titanium alloy using the welding material described above, comprising the following steps:

[0015] A2) Weighing the metal according to the welding materials designed above, and preparing an ingot after smelting;

[0016] B2) preparing the ingot into an intermediate layer material of required specifications by machining;

[0017] C2) Assemble according to the requirements of parts or blanks;

[0018] D2) Raise the temperature from room temperature to 500-600°C and keep it for 30-40 min, then raise the temperature to 700-900°C and keep it for 40-50 min, then raise the temperature to 800-1050°C and keep it for 60-70 min, and then lower the temperature to below 200°C.

[0019] Preferably, in step A2):

[0020] The smelting temperature is 900-1100° C. and the smelting time is 0.5-4 hours.

[0021] Preferably, in step D2):

[0022] The heating rate from room temperature to 500-600°C is 10-25°C / min.

[0023] Preferably, in step D2), the heating rate for heating to 700-900° C. is 35-55° C. / min.

[0024] Preferably, in step D2), the heating rate of heating to 800-1050° C. is 30-50° C. / min.

[0025] Preferably, in step D2), the cooling method is furnace cooling.

[0026] The present invention provides a method for designing a welding material for a Mo-containing high-temperature titanium alloy, comprising the following steps:

[0027] A1) The chemical formula of the welding material for Mo-containing high-temperature titanium alloy is shown in formula (1);

[0028] (a) Ti-(b) Zr-(c) X Formula (1);

[0029] In formula (1), a represents the mass content of Ti in the welding material; b represents the mass content of Zr in the welding material, b=30%; c represents the mass content of X in the welding material;

[0030] X is at least one selected from the group consisting of Mo, Sn, Ag and Gd;

[0031] In the welding material, the mass content of Ti is 20% to 50%, the mass content of Ag is 1% to 2%, and the mass content of Gd is 0 to 0.7%;

[0032] When the mass content of Mo in the Mo-containing high-temperature titanium alloy is not higher than 3.0%, the mass content of Mo in the welding material accounts for 20% of the mass content of X; when the mass content of Mo in the Mo-containing high-temperature titanium alloy is 3.0% to 5.0%, excluding 3.0%, the mass content of Mo in the welding material accounts for 30% of the mass content of X; when the mass content of Mo in the Mo-containing high-temperature titanium alloy is 5.0% to 8.0%, excluding 5.0%, the mass content of Mo in the welding material accounts for 35% of the mass content of X; when the mass content of Mo in the high-temperature titanium alloy is 8.0% to 10%, excluding 8.0%, the mass content of Mo in the welding material accounts for 40% of the mass content of X;

[0033] B1) By calculation, the a value and c value are obtained, and then the welding material for Mo-containing high-temperature titanium alloy is obtained.

[0034] The present invention is aimed at typical domestic high-temperature titanium alloys such as Ti-6Al-2.5Mo-2Cr-0.3Si-0.5Fe, Ti-6.5Al-3.3Mo-1.5Zr-0.25Si and Ti-6Al-2Sn-4Zr-6Mo, and proposes a design method and a use method of a welding material for Mo-containing high-temperature titanium alloys through research. The material is a solid solution Ti-Sn-Zr-(MoAgGd) alloy. The design method is simple and easy, the process operability is strong, and the joint strength is better. DETAILED DESCRIPTION

[0035] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] The present invention provides a method for designing a welding material for a Mo-containing high-temperature titanium alloy, comprising the following steps:

[0037] A1) The chemical formula of the welding material for Mo-containing high-temperature titanium alloy is shown in formula (1);

[0038] (a) Ti-(b) Zr-(c) X Formula (1);

[0039] In formula (1), a represents the mass content of Ti in the welding material; b represents the mass content of Zr in the welding material, b=30%; c represents the mass content of X in the welding material;

[0040] X is at least one selected from the group consisting of Mo, Sn, Ag and Gd;

[0041] In the welding material, the mass content of Ti is 20% to 50%, the mass content of Ag is 1% to 2%, and the mass content of Gd is 0 to 0.7%;

[0042] When the mass content of Mo in the Mo-containing high-temperature titanium alloy is not higher than 3.0%, the mass content of Mo in the welding material accounts for 20% of the mass content of X; when the mass content of Mo in the Mo-containing high-temperature titanium alloy is 3.0% to 5.0%, excluding 3.0%, the mass content of Mo in the welding material accounts for 30% of the mass content of X; when the mass content of Mo in the Mo-containing high-temperature titanium alloy is 5.0% to 8.0%, excluding 5.0%, the mass content of Mo in the welding material accounts for 35% of the mass content of X; when the mass content of Mo in the high-temperature titanium alloy is 8.0% to 10%, excluding 8.0%, the mass content of Mo in the welding material accounts for 40% of the mass content of X;

[0043] B1) By calculation, the a value and c value are obtained, and then the welding material for Mo-containing high-temperature titanium alloy is obtained.

[0044] In certain embodiments of the present invention, the Mo-containing high-temperature titanium alloy includes Ti-6Al-2.5Mo-2Cr-0.3Si-0.5Fe, Ti-6.5Al-3.3Mo-1.5Zr-0.25Si or Ti-6Al-2Sn-4Zr-6Mo, Ti-6Al-2.9Mo-2Cr-0.3Si-0.5Fe, Ti-5.5Al-3.5Sn-3Zr-1Nb-0.3Mo-0.3Si or Ti-6Al-5Sn-5Zr-8Mo.

[0045] The following is the description for the Mo-containing high-temperature titanium alloy Ti-6Al-2.5Mo-2Cr-0.3Si-0.5F:

[0046] 6Al means that the mass content of Al in the Mo-containing high-temperature titanium alloy is 6%, 2.5Mo means that the mass content of Mo in the Mo-containing high-temperature titanium alloy is 2.5%, 2Cr means that the mass content of Cr in the Mo-containing high-temperature titanium alloy is 2%, 0.3Si means that the mass content of Si in the Mo-containing high-temperature titanium alloy is 0.3%, and 0.5F means that the mass content of F in the Mo-containing high-temperature titanium alloy is 0.5%.

[0047] Other Mo-containing high-temperature titanium alloys are expressed in a similar manner.

[0048] In certain embodiments of the present invention, the welding material represented by formula (1) specifically comprises:

[0049] (42)Ti-(30)Zr-(5.6)Mo-(20.4)Sn-(2)Ag,

[0050] (30)Ti-(30)Zr-(8)Mo-(30.5)Sn-(1)Ag-(0.5)Gd,

[0051] (25)Ti-(30)Zr-(9)Mo-(34)Sn-(1.4)Ag-(0.6)Gd,

[0052] Or (22)Ti-(30)Zr-(1.68)Mo-(34.82)Sn-(1.4)Ag-(0.1)Gd.

[0053] The explanation for (42)Ti-(30)Zr-(5.6)Mo-(20.4)Sn-(2)Ag is as follows:

[0054] (42)Ti represents that the mass content of Ti in the welding material shown in formula (1) is 42%, (30)Zr represents that the mass content of Zr in the welding material shown in formula (1) is 30%, (5.6)Mo represents that the mass content of Mo in the welding material shown in formula (1) is 5.6%, (20.4)Sn represents that the mass content of Sn in the welding material shown in formula (1) is 20.4%, and (2)Ag represents that the mass content of Ag in the welding material shown in formula (1) is 2%.

[0055] The other welding materials represented by formula (1) are expressed in a similar manner.

[0056] The present invention also provides a method for welding a Mo-containing high-temperature titanium alloy using the welding material designed above, comprising the following steps:

[0057] A2) Weighing the metal according to the welding materials designed above, and preparing an ingot after smelting;

[0058] B2) preparing the ingot into an intermediate layer material of required specifications by machining;

[0059] C2) Assemble according to the requirements of parts or blanks;

[0060] D2) Raise the temperature from room temperature to 500-600°C and keep it for 30-40 min, then raise the temperature to 700-900°C and keep it for 40-50 min, then raise the temperature to 800-1050°C and keep it for 60-70 min, and then lower the temperature to below 200°C.

[0061] In step A2):

[0062] In certain embodiments of the present invention, the smelting temperature is 900-1100° C., such as 1010° C., 970° C., 1030° C., 1080° C.; and the smelting time is 0.5-4 h, such as 0.5 h, 1 h, 1.5 h.

[0063] In step B2):

[0064] The present invention has no particular limitation on the machining method, and conventional machining methods well known to those skilled in the art may be used.

[0065] In step C2):

[0066] Assemble according to the requirements of parts or blanks.

[0067] Specifically, the parts or blanks are assembled according to the assembly relationship, position and sequence relationship between them.

[0068] In step D2):

[0069] In certain embodiments of the present invention, the heating rate from room temperature to 500-600° C. is 10-25° C. / min.

[0070] In certain embodiments of the present invention, the heating rate to 700-900° C. is 35-55° C. / min.

[0071] In certain embodiments of the present invention, the heating rate for heating to 800-1050° C. is 30-50° C. / min.

[0072] In certain embodiments of the present invention, the temperature reduction method is furnace cooling.

[0073] After the temperature drops below 200℃, it can be taken out of the furnace.

[0074] In step D2) of the present invention, a process method of first diffusion, then brazing and then diffusion is adopted:

[0075] 500-600℃ is the first temperature section. In the first temperature section, i.e. the low melting point micro-region formation stage, the Ag element in the welding material first diffuses into the high temperature titanium alloy and forms a low melting point micro-region with the Al element, Sn element or Zr element in the high temperature titanium alloy; 700-900℃ is the second temperature section. In the second temperature section, i.e. the intermediate layer alloy strengthening and melting stage, the melting point and strength of the welding material are increased due to the reduction of the Ag element content. In the subsequent higher temperature section, the welding material melts and penetrates into the welded part; at the same time, the fluidity of the low melting point micro-region is improved, and the requirements of the weld fullness of the complex joint are better taken into account. 800-1050℃ is the third temperature section. In the third temperature section, i.e. the homogenization stage, the uniformity of the elements in the joint is improved by keeping the temperature at an appropriate temperature and time.

[0076] Beneficial effects:

[0077] 1) A general welding material (i.e., intermediate layer alloy) design method is proposed for a series of high-temperature titanium alloys. The structure of the welding material obtained by this method belongs to the solid solution type, and there is no compound. Therefore, the welding material itself has high strength and good toughness. It is more conducive to obtaining higher joint strength of high-temperature titanium alloys and reducing brittleness problems.

[0078] 2) A process method of diffusion first, brazing second and diffusion third is proposed, which utilizes some elements to diffuse first to form low melting point micro-areas to solve the problem of difficult filling of complex interface parts; and utilizes the welding material to improve its strength after the diffusion of some elements to solve the problem of insufficient strength of the welded joint.

[0079] The present invention has no particular limitation on the sources of the raw materials used above, and they can be generally commercially available.

[0080] In order to further illustrate the present invention, the design method and use method of a Mo-containing high-temperature titanium alloy welding material provided by the present invention are described in detail below in combination with embodiments, but it should not be understood as limiting the scope of protection of the present invention.

[0081] Example 1

[0082] A Mo-containing high-temperature titanium alloy, whose composition is Ti-6Al- <h2 style=";text-align:left;direction:ltr">2.5 MB -2Cr-0.3Si-0.5Fe.

[0083] 1) The design method of the Mo-containing high-temperature titanium alloy welding material includes:

[0084] The welding material is designed to be (a) Ti-(b) Zr-(c) X, where X includes Mo, Sn and Ag; b = 30%;

[0085] The mass content of Ti in the designed welding material is W Ti =a=42%; then the mass content of X in the welding material is: W X =c=100%-30%-42%=28%;

[0086] The mass content of Gd in the designed welding material is W Gd =0; the mass content of Ag in the designed welding material is W Ag =2%;

[0087] The sum of the mass content of Mo and the mass content of Sn in the welding material is W Mo+Sn =28%-2%=26%;

[0088] Since the mass content of Mo in high-temperature titanium alloy is 2.5% (not higher than 3.0%), the mass content of Mo in the welding material is W Mo =20%×W X =20%×28=5.6%;

[0089] Then W Sn =W Mo+Sn -W Mo =26%-5.6%=20.4%.

[0090] That is, for the high temperature titanium alloy Ti-6Al-2.5Mo-2Cr-0.3Si-0.5Fe, the designed welding material (i.e., the intermediate layer alloy) is (a) Ti-(30%) Zr-(c) X, wherein X includes Mo, Sn and Ag; W Mo =5.6%, W Sn =20.4%, W Ag =2%; W Ti =42%. Then the welding material is (42)Ti-(30)Zr-(5.6)Mo-(20.4)Sn-(2)Ag.

[0091] 2) A method for welding the Mo-containing high-temperature titanium alloy using the welding material designed above:

[0092] 2-1) Weigh the metal according to the welding material designed above, and make an ingot after melting at 1010℃ for 0.5h;

[0093] 2-2) machining the ingot into an intermediate layer material of required specifications;

[0094] 2-3) Assemble according to the assembly relationship, position and sequence between parts or blanks;

[0095] 2-4) Heating from room temperature (heating rate of 20°C / min) to 520°C and keeping for 35 min, then heating (heating rate of 45°C / min) to 760°C and keeping for 45 min, then heating (heating rate of 35°C / min) to 830°C and keeping for 65 min, then cooling to 200°C with the furnace and taking out of the furnace.

[0096] According to the GB / T 11363-2008 brazing joint strength test method, the joint strength of Mo-containing high-temperature titanium alloy at room temperature was tested, and the results showed that the joint strength of Mo-containing high-temperature titanium alloy was 920MPa. The joint strength of Mo-containing high-temperature titanium alloy at high temperature was tested (according to GB / T11363-2008), and the results showed that the joint strength of Mo-containing high-temperature titanium alloy at 650℃ was 630MPa.

[0097] Example 2

[0098] A Mo-containing high-temperature titanium alloy, whose composition is Ti-6Al- <h2 style=";text-align:left;direction:ltr"> 2.9 MB -2Cr-0.3Si-0.5Fe.

[0099] 1) The design method of the Mo-containing high-temperature titanium alloy welding material includes:

[0100] The welding material is designed to be (a) Ti-(b) Zr-(c) X, where X includes Mo, Sn and Ag; b = 30%;

[0101] The mass content of Ti in the designed welding material is W Ti =a=30%; then the mass content of X in the welding material is: W X =c=100%-30%-30%=40%;

[0102] The mass content of Gd in the designed welding material is W Gd =0.5; the mass content of Ag in the designed welding material is W Ag =1%;

[0103] The sum of the mass content of Mo and the mass content of Sn in the welding material is W Mo+Sn =40%-1.5%=38.5%;

[0104] Since the mass content of Mo in high-temperature titanium alloy is 2.9% (not higher than 3.0%), the mass content of Mo in welding material W Mo =20%×W X =20%×40%=8%;

[0105] Then W Sn =W Mo+Sn -W Mo =38.5%-8%=30.5%.

[0106] That is, the designed welding material (i.e., the intermediate layer alloy) is (a) Ti-(30%) Zr-(c) X, wherein X includes Mo, Sn, and Ag; W Mo =8%, W Sn =30.5%, W Ag =1%; W Ti =30%,W Gd =0.5. Then the welding material is (30)Ti-(30)Zr-(8)Mo-(30.5)Sn-(1)Ag-(0.5)Gd.

[0107] 2) A method for welding the Mo-containing high-temperature titanium alloy using the welding material designed above:

[0108] 2-1) Weigh the metal according to the welding materials designed above, and make an ingot after smelting at 1080°C for 0.5h;

[0109] 2-2) machining the ingot into an intermediate layer material of required specifications;

[0110] 2-3) Assemble according to the assembly relationship, position and sequence between parts or blanks;

[0111] 2-4) The temperature was raised from room temperature (heating rate of 20°C / min) to 540°C and kept for 38 min, then raised (heating rate of 45°C / min) to 760°C and kept for 40 min, then raised (heating rate of 35°C / min) to 840°C and kept for 70 min, then cooled to 200°C and taken out of the furnace.

[0112] According to the GB / T 11363-2008 brazing joint strength test method, the joint strength of Mo-containing high-temperature titanium alloy at room temperature was tested, and the results showed that the joint strength of Mo-containing high-temperature titanium alloy was 920-930MPa. The joint strength of Mo-containing high-temperature titanium alloy at high temperature was tested (according to GB / T 11363-2008), and the results showed that the joint strength of Mo-containing high-temperature titanium alloy at 650℃ was 637MPa.

[0113] Example 3

[0114] A Mo-containing high-temperature titanium alloy, whose composition is Ti-5.5Al-3.5Sn-3Zr-1Nb- <h2 style=";text-align:left;direction:ltr"> 0.3 MB -0.3Si.

[0115] 1) The design method of the Mo-containing high-temperature titanium alloy welding material includes:

[0116] The welding material is designed to be (a) Ti-(b) Zr-(c) X, where X includes Mo, Sn and Ag; b = 30%;

[0117] The mass content of Ti in the designed welding material is W Ti =a=25%; then the mass content of X in the welding material is: W X =c=100%-30%-25%=45%;

[0118] The mass content of Gd in the designed welding material is W Gd =0.6; the mass content of Ag in the designed welding material is W Ag =1.4%;

[0119] The sum of the mass content of Mo and the mass content of Sn in the welding material is W Mo+Sn =45%-2%=43%;

[0120] Since the mass content of Mo in high-temperature titanium alloy is 0.3% (not higher than 3.0%), the mass content of Mo in the welding material is W Mo =20%×W X =20%×45%=9%;

[0121] Then W Sn =W Mo+Sn -W Mo =43%-9%=34%.

[0122] That is, the designed welding material (i.e., the intermediate layer alloy) is (a) Ti-(30%) Zr-(c) X, wherein X includes Mo, Sn, and Ag; W Mo =9%, W Sn =34%, W Ag =1.4%; W Ti =25%,W Gd =0.6. Then the welding material is (25)Ti-(30)Zr-(9)Mo-(34)Sn-(1.4)Ag-(0.6)Gd.

[0123] 2) A method for welding the Mo-containing high-temperature titanium alloy using the welding material designed above:

[0124] 2-1) Weigh the metal according to the welding material designed above, and make an ingot after melting at 970℃ for 1h;

[0125] 2-2) machining the ingot into an intermediate layer material of required specifications;

[0126] 2-3) Assemble according to the assembly relationship, position and sequence between parts or blanks;

[0127] 2-4) Heating from room temperature (heating rate of 20°C / min) to 550°C and keeping for 40 min, then heating (heating rate of 45°C / min) to 800°C and keeping for 40 min, then heating (heating rate of 35°C / min) to 880°C and keeping for 60 min, then cooling to 200°C and taking out of the furnace.

[0128] According to the GB / T 11363-2008 brazing joint strength test method, the joint strength of Mo-containing high-temperature titanium alloy at room temperature was tested, and the results showed that the joint strength of Mo-containing high-temperature titanium alloy was 900-915MPa. The joint strength of Mo-containing high-temperature titanium alloy at high temperature was tested (according to GB / T11363-2008), and the results showed that the joint strength of Mo-containing high-temperature titanium alloy at 650℃ was 625MPa.

[0129] Example 4

[0130] A Mo-containing high-temperature titanium alloy, whose composition is Ti-6Al-5Sn-5Zr- <h2 style=";text-align:left;direction:ltr"> 8Mo .

[0131] 1) The design method of the Mo-containing high-temperature titanium alloy welding material includes:

[0132] The welding material is designed to be (a) Ti-(b) Zr-(c) X, where X includes Mo, Sn and Ag; b = 30%;

[0133] The mass content of Ti in the designed welding material is W Ti =a=22%; then the mass content of X in the welding material is: W X =c=100%-30%-22%=48%;

[0134] The mass content of Gd in the designed welding material is W Gd =0.1; the mass content of Ag in the designed welding material is W Ag =1.4%;

[0135] The sum of the mass content of Mo and the mass content of Sn in the welding material is W Mo+Sn =48%-1.5%=36.5%;

[0136] Since the mass content of Mo in high-temperature titanium alloy is 8% (higher than 3.0%), the mass content of Mo in welding material W Mo =35%×W X =35%×48%=1.68%;

[0137] Then W Sn =W Mo+Sn -W Mo =36.5%-1.68%=34.82%.

[0138] That is, the designed welding material (i.e., the intermediate layer alloy) is (a) Ti-(30%) Zr-(c) X, wherein X includes Mo, Sn, and Ag; W Mo =1.68%, W Sn =34.82%, W Ag =1.4%; W Ti =22%,W Gd =0.1. Then the welding material is (22)Ti-(30)Zr-(1.68)Mo-(34.82)Sn-(1.4)Ag-(0.1)Gd.

[0139] 2) A method for welding the Mo-containing high-temperature titanium alloy using the welding material designed above:

[0140] 2-1) Weigh the metal according to the welding materials designed above, and make an ingot after smelting at 1030°C for 1.5h;

[0141] 2-2) machining the ingot into an intermediate layer material of required specifications;

[0142] 2-3) Assemble according to the assembly relationship, position and sequence between parts or blanks;

[0143] 2-4) The temperature was raised from room temperature (heating rate of 20°C / min) to 590°C and kept for 40 min, then the temperature was raised (heating rate of 45°C / min) to 890°C and kept for 40 min, then the temperature was raised (heating rate of 35°C / min) to 980°C and kept for 55 min, then the temperature was cooled to 200°C and taken out of the furnace.

[0144] According to the GB / T 11363-2008 brazing joint strength test method, the joint strength of Mo-containing high-temperature titanium alloy at room temperature was tested, and the results showed that the joint strength of Mo-containing high-temperature titanium alloy was 905-925MPa. The joint strength of Mo-containing high-temperature titanium alloy at high temperature was tested (according to GB / T 11363-2008), and the results showed that the joint strength of Mo-containing high-temperature titanium alloy at 650℃ was 631MPa.

[0145] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for designing welding materials for Mo-containing high-temperature titanium alloys, comprising the following steps: A1) The chemical formula of the welding material for Mo-containing high-temperature titanium alloy is shown in formula (1); (a)Ti-(b)Zr-(c)X formula (1); In formula (1), a represents the mass content of Ti in the welding material; b represents the mass content of Zr in the welding material, b=30%; c represents the mass content of X in the welding material; X is at least one selected from the group consisting of Mo, Sn, Ag and Gd; In the welding material, the mass content of Ti is 20% to 50%, the mass content of Ag is 1% to 2%, and the mass content of Gd is 0 to 0.7%; When the mass content of Mo in the Mo-containing high-temperature titanium alloy is not higher than 3.0%, the mass content of Mo in the welding material accounts for 20% of the mass content of X; when the mass content of Mo in the Mo-containing high-temperature titanium alloy is 3.0%~5.0%, excluding 3.0%, the mass content of Mo in the welding material accounts for 30% of the mass content of X; when the mass content of Mo in the Mo-containing high-temperature titanium alloy is 5.0%~8.0%, excluding 5.0%, the mass content of Mo in the welding material accounts for 35% of the mass content of X; when the mass content of Mo in the high-temperature titanium alloy is 8.0%~10%, excluding 8.0%, the mass content of Mo in the welding material accounts for 40% of the mass content of X; B1) By calculation, the a value and c value are obtained, and then the welding material for Mo-containing high-temperature titanium alloy is obtained.

2. The design method according to claim 1, characterized in that: The Mo-containing high-temperature titanium alloy includes Ti-6Al-2.5Mo-2Cr-0.3Si-0.5Fe, Ti-6.5Al-3.3Mo-1.5Zr-0.25Si or Ti-6Al-2Sn-4Zr-6Mo, Ti-6Al-2.9Mo-2Cr-0.3Si-0.5Fe, Ti-5.5Al-3.5Sn-3Zr-1Nb-0.3Mo-0.3Si or Ti-6Al-5Sn-5Zr-8Mo.

3. A method for welding a Mo-containing high-temperature titanium alloy using the welding material obtained by the design method according to claim 1 or 2, comprising the following steps: A2) Weigh the metal according to the welding materials designed above, and make an ingot after melting; B2) machining the ingot into an intermediate layer material of required specifications; C2) Assemble according to the requirements of parts or blanks; D2) Raise the temperature from room temperature to 500~600℃ and keep it for 30~40 min, then raise the temperature to 700~900℃ and keep it for 40~50 min, then raise the temperature to 800~1050℃ and keep it for 60~70 min, and then lower the temperature to below 200℃.

4. The method according to claim 3, characterized in that In step A2): The smelting temperature is 900-1100° C. and the smelting time is 0.5-4 h.

5. The method according to claim 3, characterized in that: In step D2): The heating rate from room temperature to 500~600℃ is 10~25℃ / min.

6. The method according to claim 3, characterized in that In step D2), the heating rate to 700-900°C is 35-55°C / min.

7. The method according to claim 3, characterized in that In step D2), the temperature is then raised to 800-1050°C at a rate of 30-50°C / min.

8. The method according to claim 3, characterized in that In step D2), the temperature reduction method is furnace cooling.