Dynamic And Static Compression Properties And Behavior Of High Speed Crash For TIB_2p/AL Composites

This paper with the spacecraft shield against high speed impact as the research background, use of pressure infiltration method of preparation of the volume fraction of 55% TiB_2p/Al composite materials, use of universal electronic tensile testing machine,Hopkinson pressure bar equipment, scanning electron microscopy and transmission electron microscopy studies of temperature and strain rate compressive mechanical properties of materials and organizational impact of the law. And the use of two light-gas gun and scanning electron microscopy study of high-speed impact resistance of composite materials after impact performance and material behavior of the macro and micro damage. This test is divided into three parts made: compression test, high speed impact testing and microstructural characterization.At room temperature, strain rate in the 10-3¹000S^-1 within the flow stress with increasing strain rate decreases, showing a negative strain rate sensitivity. When the strain rate in the 1000²000S^-1, the flow stress remained unchanged, showing no strain rate sensitivity. High temperature,flow stress with strain rate increases, and finally stabilized. Showed strain rate sensitivity. As the test temperature, the particle network structure plays a major role to enhance the strength, but inhibition of matrix alloy particles sliding ability diminishing, low strain rate reflect the particles in the matrix of the sliding characteristics, high strain rate reflects the network skeleton structure of the particle load-bearing characteristics. The same strain rate, the strength of composite decreases with increasing temperature, the higher the temperature, the more obvious decline in strength.At room temperature, the strain rate compression of the fracture at the scratches, melting zone and the matrix cracks. Temperature to 250℃and 400℃, scratches more apparent, the matrix alloy melting zone area becomes larger, particles can be observed simultaneously broken. 550℃, scratch marks disappear, crack becomes obvious, replaced by tiny cracks and gaps, and loose particles. Quasi-static compression at room temperature (strain rate 10-3S^-1), composite matrix a large number of dislocations, but as the temperature rises, the base occurs in vivo dynamic recrystallization and dynamic recrystallization of grains. In the 550℃, the matrix occurs mainly within the dynamic recovery. In each test temperature and strain rate of 10-3S^-1 than by the strain rate of 1S^-1 compressed, TiB₂ particles occur within the dislocation, dislocation density increases with temperature.After high speed impact, side impact crater depth and diameter with the increase of the diameter of the projectile, crater back without caving, perforation and other damage. Crater at the bottom of the organization appear to enhance breakage, cracks and defects such as loose.