CN103469135A

CN103469135A - Preparation method of high-niobium TiAl intermetallic compound

Info

Publication number: CN103469135A
Application number: CN2013104147176A
Authority: CN
Inventors: 郎泽保; 王亮; 芦振刚; 王�锋; 史金靓
Original assignee: China Academy of Launch Vehicle Technology CALT; Aerospace Research Institute of Materials and Processing Technology
Current assignee: China Academy of Launch Vehicle Technology CALT; Aerospace Research Institute of Materials and Processing Technology
Priority date: 2013-09-12
Filing date: 2013-09-12
Publication date: 2013-12-25
Anticipated expiration: 2033-09-12
Also published as: CN103469135B

Abstract

The invention relates to a preparation method of high-niobium TiAl intermetallic compound. The prepared high-niobium TiAl intermetallic compound can substitute nickel-base superalloy and other materials to be used for manufacturing heat-resisting structure components of advance aircrafts in the aviation and aerospace field, can achieve about 50% lightweight effect, and belongs to the technical field of aviation and aerospace heat-resisting materials. According to the prepared high-niobium TiAl intermetallic compound, the mechanical property sigma b is more than or equal to 800MPa, delta5 is more than or equal to 1.0%; at 1100DEG C, the mechanical property sigma b is more than or equal to 70MPa and delta5 is more than or equal to 8.0%; the internal quality of the high-niobium TiAl intermetallic compound prepared by the technique can reach the A-grade level of GJB1580A; the density of the high-niobium TiAl intermetallic compound prepared by the technique is higher than the theoretical density by 99%.

Description

A kind of preparation method of high-Nb TiAl series intermetallic compound

Technical field

The present invention relates to a kind of preparation method of high-Nb TiAl series intermetallic compound, the materials such as the alternative nickel base superalloy of high-Nb TiAl series intermetallic compound of preparation are for the manufacture of the heat resistant structure parts of the advanced aircraft of aerospace field, can obtain the lighting effect of 50% left and right, belong to aerospace heat-stable material technical field.

Background technology

The density of high-Nb TiAl series intermetallic compound is at 4.0g/cm ³left and right, have superior high-temperature behavior 900～1000 ℃ of left and right, can become in this temperature range the equivalent material of nickel base superalloy or steel alloy, thereby make the quality of these parts reduce by 50% left and right.The high-Nb TiAl series intermetallic compound has been carried out to research widely both at home and abroad, but mostly concentrated on the aspects such as alloying, melting, casting and forging of high-Nb TiAl series intermetallic compound.Because the alloying level of high-Nb TiAl series intermetallic compound is higher, composition and microtexture segregation easily appear, and then the reduction that brings the use properties reliability, hinder its application of through engineering approaches at aerospace field.

Powder metallurgical technique has purposes widely improving aspect material property.By the research at aspects such as high-Nb TiAl series intermetallic compound powder pre-treating technology, high-Nb TiAl series intermetallic compound powder vacuum sealing technique and high-Nb TiAl series intermetallic compound microtexture control techniquess, prepare the high-Nb TiAl series intermetallic compound material of homogeneous microstructure, material densification in prior art.

Summary of the invention

The objective of the invention is in order to propose a kind of preparation method of high-Nb TiAl series intermetallic compound, the method can make the high-Nb TiAl series intermetallic compound have tiny, uniform microtexture, and possesses comprehensive mechanical property preferably.

The objective of the invention is to be achieved through the following technical solutions.

The preparation method of a kind of high-Nb TiAl series intermetallic compound of the present invention, in this compound, the molar content of niobium element is not less than 5%; The high-Nb TiAl series intermetallic compound pre-alloyed powder of take is starting material, and concrete steps are:

1), by the granularity of ball milling refinement powder, improve the activity of powder surface;

2) powder is packed in the soft steel jacket, and at a certain temperature jacket is vacuumized;

3) jacket after vacuumizing is carried out to the hot isostatic pressing densification;

4) remove the soft steel jacket;

5) the high-Nb TiAl series intermetallic compound blank of acquisition is put into to the silica glass jacket, carry out the solid solution aging processing, can obtain having the high-Nb TiAl series intermetallic compound material of comprehensive mechanical property.

Beneficial effect

The mechanical property σ b ≮ 800MPa of the high-Nb TiAl series intermetallic compound of preparation of the present invention (with Ti-45Al-8.5Nb-(W, B, Y) for example), δ 5 ≮ 1.0%, under 1100 ℃, its mechanical property: σ b ≮ 70MPa, δ 5 ≮ 8.0%; The internal soundness of the high-Nb TiAl series intermetallic compound prepared by this technique reaches the A level level of GJB1580A; The density of the high-Nb TiAl series intermetallic compound prepared by this technique surpasses 99% of theoretical density.

The accompanying drawing explanation

The structure figure that Fig. 1 is the TiAl series intermetallic compound.

Embodiment

Below the present invention is further illustrated.

Embodiment 1

A kind of high-performance powder metallurgy high-Nb TiAl series intermetallic compound Ti-45Al-8.5Nb-0.2W-0.3B-0.02Y(at%) manufacture method of (following referred to as Ti-45Al-8.5Nb-(W, B, Y)) comprises the following steps:

(1) Ti-45Al-8.5Nb-(W, B, Y) pre-alloyed powder is packed into together with the diamond ball-milling ball in the titanium alloy ball grinder, and be filled with the mixed gas of argon gas and hydrogen, ratio is at the 8:1(volume ratio), Ball-milling Time 60h at room temperature.

(2) Ti-45Al-8.5Nb-after ball milling (W, B, Y) powder is packed in the soft steel jacket under the condition of vibration, and the welding gas removing pipe, gas removing pipe is connected on the vacuum unit and is vacuumized.The technique vacuumized is: at room temperature degasification time 2h, treat that in jacket, vacuum tightness is better than 3 * 10 ^-3after Pa, jacket is warming up to 260 ℃, insulation 3h, treat that in jacket, vacuum tightness is better than 4 * 10 ^-3after Pa, jacket is warming up to 680 ℃, soaking time 12h, treat that in jacket, vacuum tightness is better than 1 * 10 ^-3after Pa, the artificial envelope gas removing pipe of forging, seal gas removing pipe with argon welder after the cut-out gas removing pipe.

(3) jacket is put into to hot isostatic press and carried out the hot isostatic pressing densification, heat and other static pressuring processes is: 1280 ± 15 ℃, and 4h, pressure is 150MPa.Can obtain powder metallurgy Ti-45Al-8.5Nb-(W, B, Y) material pressed compact after hot isostatic pressing.

(4) remove the soft steel jacket of Ti-45Al-8.5Nb-(W, B, Y) pressed compact outside by the method for Vehicle Processing, obtain high-Nb TiAl series intermetallic compound blank.

(5) Ti-45Al-8.5Nb-(W, B, Y) blank is packed in the silica glass jacket, and be filled with argon gas, pressure is 5MPa, then glass bag is put into to process furnace and heat-treats.Heat treating regime is: the first step, be warming up to 1420 ℃, and soaking time is 60min, then oil quenching is to room temperature; Second step, be warming up to 980 ℃, and soaking time is 48h, finally with the stove naturally cooling, can obtain having Ti-45Al-8.5Nb-(W, B, the Y) material of tiny topsheet layer tissue, and its structure as shown in Figure 1; Its room-temperature mechanical property is tested according to GB228-2002, carries out altogether three tests, and the tensile strength of test is 810MPa for the first time, and yield strength is 760MPa, and unit elongation is 1.2%, and reduction of area is 2.5%;

The tensile strength of test is 827MPa for the second time, and yield strength is 786MPa, and unit elongation is 1.0%, and reduction of area is 2.0%;

The tensile strength of test is 815MPa for the third time, and yield strength is 755MPa, and unit elongation is 1.1%, and reduction of area is 2.3%.

Claims

1. the preparation method of a high-Nb TiAl series intermetallic compound is characterized in that step is:

1) high niobium titanium aluminide prealloy powder is carried out to ball milling;

2) the high niobium titanium aluminide prealloy powder after the step 1) ball milling is packed in the soft steel jacket, and the soft steel jacket is vacuumized;

3) by step 2) in the soft steel jacket carry out the hot isostatic pressing densification, obtain the material pressed compact;

The soft steel jacket of the material pressed compact outside that 4) the removal step 3) obtains, obtain high-Nb TiAl series intermetallic compound blank;

5) high-Nb TiAl series intermetallic compound blank step 4) obtained is put into the silica glass jacket, carries out solution treatment, obtains high-Nb TiAl series intermetallic compound material, and wherein the molar content of niobium is not less than 5%.

2. the preparation method of a kind of high-Nb TiAl series intermetallic compound according to claim 1, it is characterized in that: use the titanium alloy ball grinder in step 1) during ball milling, and by diamond, high niobium titanium aluminide prealloy powder is carried out to ball milling, and be filled with argon gas that volume ratio is 8:1 and the mixed gas of hydrogen in the titanium alloy ball grinder.

3. the preparation method of a kind of high-Nb TiAl series intermetallic compound according to claim 1, is characterized in that: step 2) in technique that the soft steel jacket is vacuumized be: degasification 2h at room temperature, treat that in the soft steel jacket, vacuum tightness is better than 3 * 10 ^-3after Pa, the soft steel jacket is warming up to 260 ℃, insulation 3h, treat that in the soft steel jacket, vacuum tightness is better than 4 * 10 ^-3after Pa, the soft steel jacket is warming up to 680 ℃, soaking time 12h, finally make the vacuum tightness in the soft steel jacket be better than 1 * 10 ^-3pa.

4. the preparation method of a kind of high-Nb TiAl series intermetallic compound according to claim 1 is characterized in that: the technique of in step 3), the soft steel jacket being carried out to the hot isostatic pressing densification is: temperature is 1280 ℃, and pressure is 150MPa, and the time is 4h.

5. the preparation method of a kind of high-Nb TiAl series intermetallic compound according to claim 1, is characterized in that: in step 4), use the method for Vehicle Processing to remove the soft steel jacket.

6. the preparation method of a kind of high-Nb TiAl series intermetallic compound according to claim 1, it is characterized in that: in step 5), the process of solution treatment is: in the silica glass jacket, be filled with argon gas, pressure is 5MPa, then the silica glass jacket being put into to process furnace heat-treats, thermal treatment temp is: the first step, be warming up to 1420 ℃, soaking time is 60min, and then oil quenching is to room temperature; Second step, be warming up to 980 ℃, and soaking time is 48h, finally with the stove naturally cooling.