Method for acquiring highly-adaptive abrasion-proof titanium-based composite material on titanium alloy surface

Abstract

The invention discloses a method for preparing a Ti-based composite with high adaptability on a Ti-alloy surface, which pertains to the field of surface modification of metallic materials. The method comprises such procedures as: weighing by certain proportion spherical Ti alloy powder particles in proper particle sizes (45-150 micro meter) and TiB2, Cr3C2, TiC or B4C powder particles (3.4-30vol%, particle size 38-106 micrometer); mixing the powder evenly by a mechanical way; sending at the set powder-feeding rate the mixed powder by a powder feeder and coaxial powder-feeding nozzles into a molten bath formed by a high-power laser at the surface of a Ti-alloy substrate; the mixed powder carrying out in-situ reaction by the high temperature from the molten bath, and forming such steady and dispersion reinforced phases as in-situ self-grown TiC or TiB. The reinforced phases are featured by small particle size, steady thermal and mechanical properties, free pollution in interfaces, and high bond strength with the substrate. The method can substantially improve the hardness and wear resistance of Ti alloy surfaces, guarantees the high adaptability between the surface modified layer and the substrate, can be used for repairing and surface reinforcing treatment of Ti alloy parts bearing impact vibration load and thermal fatigue, etc.

Description

technical field [0001] The invention relates to a method for obtaining a highly compatible and wear-resistant titanium-based composite material on the surface of a titanium alloy, belonging to the field of surface modification of metal materials. Background technique [0002] Due to their low density, high specific strength, high yield ratio, corrosion resistance and good high-temperature mechanical properties, titanium and titanium alloys are used in aviation, aerospace, ships, weapons, petroleum, chemical, medical and other fields. However, due to the shortcomings of titanium alloys such as low hardness, poor wear resistance, large friction coefficient and instability, the wider application is limited. The hardness of pure titanium is about 150-200HV, and the hardness of titanium alloy is generally lower than 350HV. Aiming at the disadvantage of poor wear resistance of titanium alloys, a variety of surface modification technologies for titanium alloys have been developed....

AI Technical Summary

Problems solved by technology

The pre-powder method is generally only suitable for cladding a layer of material on the surface of the material, and the thickness of the cladding layer is limited. If the powder is too thick, it is difficult to ensure the metallurgical bonding between the coating and the substrate and good coating performance during cladding; The coating formed by laser cladding SiC, TiC and WC directly on the surface of titanium alloy is brittle and prone to cracks; laser cladding NiCrBSi, NiCrBSi+TiC, Ti-Co, Cr-Ni-Si, Ti-Ni-Si, etc. A large amount of brittle intermetallic compound phases will be generated in the coating, and the toughness of the coating is poor; these cladding coatings have a good effect in improving the surface hardness and wear resistance of the material, but due to the low toughness of the coating , which is quite different from the thermophysical properties of the base material, and cannot meet the requirements of the aircraft engine parts under the shock vibration load and thermal fatigue conditions

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