Technology And Mechanism Of Large Deformation Strengthening For Tungsten Heavy Alloy

In this paper, the relationship between the microstructure and mechanical properties after deformation strengthening of tungsten alloy for penetrator was studied.The tungsten alloy materials were prepared by powder metallurgy, and then, the deformed materials with different microstructure and properties were obtained by forging technique and heat treatment processes.The quasi-static tensile experiment and impact toughness experiment were carried out to study the relationship between the microstructure and mechanical properties. The results show that with the increase of deformation amount, the tensile property is improved and the toughness is decreased. The microstructures analysis shows that the fiber tendency of tungsten grain increases with deformation amount increasing. The observation of SEM images for fracture surface shows that with the increase of deformation amount, the proportion of tungsten-matrix interface separation, tungsten-tungsten interface separation and matrix ductile failure decreases, and the proportion of tungsten cleavage increases.Based on the design thought and research results of composite material, the systematic analysis on the dependence of properties on microstructure was done for the first time. The fracture mechanism of tungsten alloy after deformation changes greatly, which is due to the stress transferring from matrix to tungsten grain and the restraining force of tungsten grain on matrix increasing after the deformed tungsten grain becomes fibrous. Besides, the deformation strengthening increases the interface strength and decreases contiguity between W grains. The plastic deformation of tungsten particles and matrix also leads to strength improvement of themselves.