Near clean shaping preparation method of granular reinforced metal base composite material based on region selection laser sintering

Abstract

A method based on laser sinter in chosen region for preparing the ceramic particles-reinforced metal-based composition features that the selective laser sintering (SLS) method is used for easily controlling the volume percentage of reinforcing phase, and the vacuum pressure-varying percolation method is used for controlling the technological parameters (vacuum degree, and the pressure and temp of osmosis). It can be used to shape large thin-wall workpiece with complex shape.

Description

technical field [0001] The present invention relates to composite materials, in particular to a near-net-shape preparation method for particle-reinforced metal matrix composite materials based on selective laser sintering (Selective laser sintering, SLS) for ceramic particles. Background technique: [0002] Particle-reinforced metal matrix composites have excellent mechanical and physical properties such as high specific strength and specific stiffness, wear resistance, low density, good dimensional stability and thermal conductivity. It can be widely used in aerospace, military, automobile, electronics, sports and other fields. Therefore, since the early 1980s, countries all over the world have been competing to research and develop such materials, and have carried out many basic research work from the perspectives of material preparation technology, microstructure, mechanical properties and fracture characteristics, and have achieved remarkable results. At present, develo...

AI Technical Summary

Problems solved by technology

In the casting method, the disadvantages of the liquid stirring method are: the high-speed stirring liquid metal will be wrapped in gas and inclusions, there will be segregation, the mixing and compounding process is also quite difficult, and the amount of addition is also limited; the shortcomings of the semi-solid stirring method It is because the melt has a high density, which is not conducive to the discharge of impurities and gases, and it is difficult to control the temperature; the ordinary piezo-infiltration method has the problem that the internal structure is not dense enough, and in order to ensure that the melt has a certain fluidity after compounding

The particle size is generally larger than 10 μm, and the reinforcement effect is limited to a certain extent; due to the poor wettability of the ceramic reinforcement particles and the molten metal, it is difficult to achieve a uniform distribution of the reinforcement particles in the stirred casting method. At the same time, the reinforcement particles are easily mixed with the metal melt Severe chemical reactions occur, and the interface bonding is also poor. In addition, the size of reinforcement particles usually needs to be larger than 10 μm, and the volume content is generally about 20%

These preparation methods are difficult to meet the requirements of uniform dispersion of fine-grained reinforcements in composite materials, good interfacial bonding with the matrix, easy control of the volume fraction of reinforcements, high volume fractions, and large-scale complex thin-walled composites. The existing casting method has the disadvantages of uneven dispersion of the reinforcing phase in the matrix, resulting in low performance, difficulty in obtaining high volume fraction, and large and complex thin-walled composite components.

Images