阅读说明：本技术 一种高性能tb8型钛合金基复合材料的制备方法 (Preparation method of high-performance TB8 type titanium alloy-based composite material ) 是由 许晓静 陈浩 黄锦栋 刘庆军 张旭 刘阳光 肖易水 蒋泽 毛强 张天赐 于 2019-09-12 设计创作，主要内容包括：一种高性能TB8型钛合金基复合材料的制备方法,其特征是它以90wt.%Ti合金粉末(Ti-14.26Mo-2.45Nb-2.86A1-0.18Si)和10wt.%纯Ti粉末作为复合材料的基体粉末,再加入1.0wt.%CNTs增强体粉末通过放电等离子烧结原位反应而成。本发明中复合材料的抗压强度高达1725Mpa,断裂压缩率为26.2%。复合材料在750℃下氧化100h后样品单位面积增重为1.5628 mg·cm<Sup>-2</Sup>,氧化膜层较薄,厚度大约为10μm,生长连续均匀,与基体之间没有断层,在750℃的熔盐中腐蚀下复合材料后热腐蚀的单位面积腐蚀增重(14.2513 mg·cm<Sup>-2</Sup>)。(The preparation method of the high-performance TB8 type titanium alloy matrix composite is characterized in that 90wt.% of Ti alloy powder (Ti-14.26 Mo-2.45Nb-2.86A1-0.18 Si) and 10wt.% of pure Ti powder are used as matrix powder of the composite, and 1.0wt.% of CNTs reinforcement powder is added to the matrix powder to perform in-situ reaction through spark plasma sintering. The compressive strength of the composite material in the invention is as high as 1725Mpa, fracture compression 26.2%. The weight gain of the composite material per unit area after being oxidized for 100 hours at 750 ℃ is 1.5628 mg-cm ‑2 The oxide film layer is thin and has a thickness of about 10 mu m, the growth is continuous and uniform, no fault exists between the oxide film layer and the substrate, and the corrosion weight per unit area of the composite material after hot corrosion is increased (14.2513 mg cm) under the corrosion in 750 ℃ molten salt ‑2 )。)

1. The preparation method of the high-performance TB8 type titanium alloy matrix composite is characterized in that the composite is prepared by compounding 99wt.% of titanium matrix (matrix powder consisting of 90wt.% of Ti alloy powder (Ti-14.26 Mo-2.45Nb-2.86A1-0.18 Si) and 10wt.% of pure Ti powder) and 1.0wt.% of CNTs reinforcement through the technical route of wet grinding of the reinforcement, adding of the matrix for wet grinding, dry grinding, drying, powder screening and spark plasma sintering.

2. A method of manufacturing as claimed in claim 1, characterized in that it comprises the following steps:

(1) sieving 90wt.% Ti alloy powder (Ti-14.26 Mo-2.45Nb-2.86A1-0.18 Si) and 10wt.% pure Ti powder with 300 mesh sieve;

(2) wet milling 1.0wt.% CNTs, setting the rotation speed of the ball mill to be 300 +/-50 r/min, and setting the ball milling time to be 24 h.

(3) Putting 90wt.% of Ti-Mo-Nb-A1-Si series titanium alloy powder and 10wt.% of pure Ti powder which are sieved by a 300-mesh sieve and 1.0wt.% of CNTs reinforcement after wet grinding into a ball mill for wet grinding to obtain composite powder, wherein the rotating speed of the ball mill is set to be 300 +/-50 r/min, and the total ball grinding time is 48 h;

(4) drying: placing the wet-milled composite powder in a vacuum drying oven, heating to 70 ℃ along with the drying oven, and then preserving heat for 12 hours;

(5) dry grinding: putting the dried composite powder into a ball mill for dry milling, wherein the rotating speed of the ball mill is set to be 300 +/-50 r/min, and the ball milling time is 6 hours;

(6) sieving: the composite powder after dry grinding is sieved by 200 meshes;

(7) spark plasma sintering: the sintering process comprises heating rate of 100 + -5 deg.C/min, sintering temperature of 1350 + -10 deg.C, sintering pressure of 50 + -5 MPa, and heat preservation time of 10 + -1 min

(8) Solid solution aging: 850 +/-10 ℃/3 h/AC (air cooling) +550 +/-10 ℃/6 h/AC (air cooling); thus obtaining the high-performance TB8 type titanium alloy matrix composite material.

3. The method of claim 1 or 2, wherein the 1.0wt.% CNTs reinforcement is characterized by nanoscale dimensions and high elastic modulus and low density.

Technical Field

The invention relates to a preparation technology of a titanium-based composite material, in particular to a TiC-enhanced titanium-based composite material, and specifically relates to a titanium-based composite material which takes CNTs and TB8 type titanium alloy as raw materials and generates a TiC enhanced phase through in-situ reaction of spark plasma sintering.

Background

Compared with the base alloy, the titanium-based composite material has the characteristics of small density, high specific strength, high temperature resistance and the like, and has wide application prospect in the fields of aerospace, weaponry and the like. TiC is a common reinforcement of titanium-based composite materials, the TiC-reinforced titanium-based composite materials are mainly prepared by an external reinforcement method and a liquid phase original reaction method at present, the external method is not enough to enable the reinforcement and a matrix to be fully combined, and the original reaction can enable the compactness of material tissues to be good.

The TB8 type titanium alloy usually has a heat-resisting temperature not higher than 600 ℃ so as to limit the application range, however, the selected reinforcement powder is CNTs, the CNTs have a nano-scale size and a large length-diameter ratio, and have high elastic modulus and low density, so that the heat-resisting property of the titanium-based composite material can be obviously improved. The spark plasma sintering has the characteristics of low reaction temperature, high temperature rise speed, short sintering time and the like, is carried out under certain pressure, and can ensure that the compactness of the material structure is better.

So far, no technical route for preparing a titanium-based composite material by using discharge plasma sintering by using CNTs and TB8 type titanium alloy as raw materials exists.

Disclosure of Invention

The invention aims to solve the problems that the existing titanium alloy material is single in preparation method and the performance of the existing titanium alloy material is limited to be difficult to improve, and provides a method for preparing a high-performance TB8 type titanium alloy based composite material by using CNTs and TB8 type titanium alloy as raw materials and utilizing technical routes of wet grinding reinforcement, matrix wet grinding, dry grinding, drying, powder screening, discharge plasma sintering and the like.

The technical scheme of the invention is as follows:

the preparation method of the high-performance TB8 type titanium alloy-based composite material is characterized in that 90wt.% of Ti alloy powder (Ti-14.26 Mo-2.45Nb-2.86A1-0.18 Si) and 10wt.% of pure Ti powder are used as matrix powder of the composite material, 1.0wt.% of CNTs is used as a source supply body of an reinforcement, and the high-performance TB8 type titanium alloy-based composite material is prepared by a technical route of wet grinding of the reinforcement, addition of matrix wet grinding, dry grinding, drying, powder screening and spark plasma sintering. The method comprises the following specific steps:

(1) sieving 90wt.% Ti alloy powder (Ti-14.26 Mo-2.45Nb-2.86A1-0.18 Si) and 10wt.% pure Ti powder with 300 mesh sieve;

(2) wet grinding 1.0wt.% CNTs, setting the rotating speed of a ball mill to be 300 +/-50 r/min, and setting the ball milling time to be 24 h;

(3) putting 90wt.% of Ti-Mo-Nb-A1-Si series titanium alloy powder and 10wt.% of pure Ti powder which are sieved by a 300-mesh sieve and 1.0wt.% of CNTs reinforcement after wet grinding into a ball mill for wet grinding to obtain composite powder, wherein the rotating speed of the ball mill is set to be 300 +/-50 r/min, and the ball milling time is 48 h;

(4) drying: placing the wet-milled composite powder in a vacuum drying oven, heating to 70 ℃ along with the drying oven, and then preserving heat for 12 hours;

(5) dry grinding: putting the dried composite powder into a ball mill for dry milling, wherein the rotating speed of the ball mill is set to be 300 +/-50 r/min, and the ball milling time is 6 hours;

(6) sieving: the composite powder after dry grinding is sieved by 200 meshes;

(7) spark plasma sintering: the sintering process comprises heating rate of 100 + -5 deg.C/min, sintering temperature of 1350 + -10 deg.C, sintering pressure of 50 + -5 MPa, and heat preservation time of 10 + -1 min

(8) Solid solution aging: 850 +/-10 ℃/3 h/AC (air cooling) +550 +/-10 ℃/6 h/AC (air cooling); thus obtaining the high-performance TB8 type titanium alloy matrix composite material.

The 1.0wt.% CNTs reinforcement is characterized by nanoscale dimensions, high elastic modulus, and low density.

The invention has the beneficial effects that:

(1) the invention innovatively provides a composite material which takes CNTs and TB8 type alloy as raw materials, TiC is generated by using discharge plasma sintering in-situ reaction, and the TiC has a reinforcing effect on a matrix, so that the comprehensive performance of the composite material can be improved.

(2) Compared with the argon protection sintering mode, the compressive strength of the matrix alloy material and the compressive strength of the composite material are respectively improved by 457 MPa and 462 MPa. Wherein, in the argon protection sintering, the compression strength of the matrix material is 1038 MPa, and the fracture compression ratio is 13.3%. The composite material with 1wt.% of CNTs has the compression strength of 1263 MPa and the fracture compression ratio of 18.5%; in spark plasma sintering, the compressive strength of the matrix alloy is 1495MPa, and the compressive strength of the composite material added with 1wt.% of CNTs reaches 1725 MPa.

(3) The increase of the unit area of an oxidation layer of the matrix alloy prepared by the spark plasma sintering process after being oxidized for 100 hours at 750 ℃ is reduced by about 64.41 percent compared with that prepared by argon protection sintering, and the increase of the unit area of the matrix alloy added with 1.0wt.% of CNTs composite material is reduced by about 41.23 percent compared with that prepared by argon protection sintering.

Drawings

FIG. 1 is the microstructure and EDS element distribution of the matrix and composite of the present invention; (a) a substrate; (b) 1.0wt.% CNTs; (c) c element distribution; (d) ti element distribution;

FIG. 2 is an XRD pattern of a matrix of the present invention and a composite incorporating 1.0wt.% CNTs reinforcement;

FIG. 3 is the apparent porosity of the matrix and composite with 1.0wt.% CNTs reinforcement added in accordance with the present invention;

FIG. 4 is a stress-strain curve of a matrix of the present invention and a composite incorporating 1.0wt.% CNTs reinforcement; (a) a substrate; (b) 1.0wt.% CNTs;

FIG. 5 is a graph of the oxidation kinetics of a matrix of the present invention and a composite material incorporating 1.0wt.% CNTs reinforcement at 750 ℃ for 100h of oxidation;

FIG. 6 is an XRD pattern of a matrix of the present invention and the addition of 1.0wt.% CNTs reinforcement composite for 100h of oxidation at 750 ℃;

FIG. 7 is the oxidation cross-sectional morphology and line scan analysis of the matrix and the composite with 1.0wt.% CNTs reinforcement added after 100h oxidation at 750 ℃: (a) a substrate; (b) spark plasma sintering: 1.0wt.% CNTs; (c) and (3) argon protection sintering: 1.0wt.% CNTs;

FIG. 8 is a graph of the kinetics of corrosion in molten salt at 750 ℃ for 30 h for a matrix of the present invention and with the addition of 1.0wt.% CNTs reinforcement composite;

FIG. 9 is an XRD analysis of a matrix of the present invention and a CNTs reinforcement composite added to 1.0wt.% of molten salt at 750 ℃ after 30 h of corrosion;

FIG. 10 is a cross-sectional profile and line scan analysis of a matrix of the present invention and a 1.0wt.% CNTs reinforcement composite added in molten salt at 750 ℃ after 30 h corrosion: (a) a substrate; (b) spark plasma sintering: 1.0wt.% CNTs; (c) and (3) argon protection sintering: 1.0wt.% CNTs.

Detailed Description

The invention is further described with reference to the following figures and specific embodiments.