Method for preparing titanium-based composite material by sintering pre-dispersed graphite composite titanium hydride

Abstract

The invention belongs to the technical field of nonferrous metal processing, and discloses a method for preparing a titanium-based composite material by sintering pre-dispersed graphite composite titanium hydride and the prepared composite material. Specifically, titanium hydride powder and graphite powder are used as raw materials to form a TiC reinforced titanium-based composite material by powder metallurgy. The method comprises the following steps that firstly, the graphite powder is pre-dispersed by using polyvinylpyrrolidone; and then, the graphite powder is attached on the surface of titanium hydride for sintering formation, so that such problems as powder agglomeration and weak alloy performance caused by direct physical mixing of the titanium hydride and the graphite powder are solved. The tensile strength of the obtained TiC reinforced titanium-based composite material can be 535 MPa; the elongation after fracture can be 10%; the optimized wear volume is reduced by 15% compared with pure titanium; compared with a titanium-based composite material prepared by using titanium hydride as a raw material reported in the literature, the breakthrough in greatly improving the tensile plasticity is realized; and the method can be applied to the preparation of high-strength parts or wear-resistant structural parts in the fields of aerospace, armored cars, weapons, ships and automobiles.

Description

technical field [0001] The invention belongs to the technical field of non-ferrous metal processing, and in particular relates to a method for preparing a titanium-based composite material by sintering pre-dispersed graphite composite titanium hydride and the prepared composite material, specifically using titanium hydride powder and graphite powder as raw materials and adopting powder metallurgy forming TiC reinforced titanium matrix composites. Background technique [0002] As a non-ferrous metal material with abundant reserves, titanium has high mechanical strength, low density, excellent biocompatibility and excellent corrosion resistance. It is widely used in aerospace industry, military weapons, energy, chemical industry, shipbuilding and other fields. In order to meet the high requirements of modern industry for titanium, it must reduce production costs while continuously improving its mechanical properties and service temperature. [0003] The preparation of titaniu...

AI Technical Summary

Problems solved by technology

However, the composite materials prepared by sintering titanium hydride face the following problems: 1. The intrinsic brittleness of titanium hydride makes it easy to break into nano-powders during the process of mechanical alloying to prepare composite powders, and a large amount of impurities are introduced, resulting in extremely poor alloy properties; 2. 1. There are problems such as agglomeration of the reinforced phase, excessive size and low density after sintering when the raw material powder of the reinforced phase is mixed directly with titanium hydride; therefore, the prepared composite material has poor reinforcement effect and poor comprehensive performance

[0005] (1) High cost: high melting temperature (>1668°C) is required to consume a lot of energy when preparing titanium matrix composites by casting method; moreover, the material utilization rate of cast titanium materials is low

Most of the titanium-based composites prepared by powder metallurgy use pure titanium powder as raw material combined with mechanical alloying and high energy consumption pressure-assisted sintering (hot isostatic pressing, etc.) to prepare composite materials with small size and uniform distribution of reinforcement phase; The cost of raw materials and processing costs of titanium matrix composites are relatively high

[0006] (2) Poor mechanical properties: using titanium hydride powder as raw material to prepare titanium-based composite materials can reduce costs

However, the plasticity of titanium-based composites prepared by alloying titanium hydride and reinforcing phase particles or fibers by mechanical alloying and then pressing and sintering is extremely low; Titanium matrix composites also have problems such as high residual porosity and low tensile plasticity.

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