Fabrication Of Semisolid Slurry On AM60 Magnesium Alloy By Self-inoculation Method

Sustainable development has become the common concerns of the world with the entrance 21 st century. In order to realize the conversion of tradition high consuming pattern to sustainable developing pattern, saving and reasonable using of the resource have received the recognition. Magnesium alloy , as the lightest structural metals ,is an environment friendly materials. Its exploitation and application are very important to the development of the materials science field and society. Semisolid metal processing (SSP) technology is regarded as one of the near-net shape forming technologies in 21 century, which has a wide prospect for application, and previous studies have shown that the preparation of semisolid slurry for semisolid metal process is the key technique.A novel preparation technology for SSP was proposed in the thesis, named as self-inoculation method (SIM), and applied to prepare semisolid slurry of magnesium alloy AM60.The thesis focus on effects of pouring process on as-cast microstructure of AM60 alloy sample; Effects of self-inoculators, such as addition methods, size, addition amount and initial microstructure on as-cast microstructure of AM60 alloy; Analysis of mechanical properties for AM60 alloy produced by SIM; The partial remelting microstructure of AM60 alloy produced by various processing parameters.The experimental results show that: the as-cast microstructure of AM60 alloy is fine, which is poured by self-inoculation method at 650℃; a coarse microstructure was caused while the pouring temperature increases; many disadvantage appeared, such as difficulty in operation while the pouring temperature decrease; the smaller particles and grains of self -inoculators is, the fine the grain of as-cast AM60 alloy. The grain size is 58.4μm when the self-inoculators of SI-3# with 5mm×5mm×5mm.After 11wt% self-inoculators introduced, the grain size of AM60 magnesium alloy sample is 43μm; The tensile strength and hardness of the as-cast AM60 alloy produced by self-inoculation method were higher,σ_b=177MPa, HV₃₀=58.8 than those of conventional liquid casting; The solid particles size of semisolid microstructure by self-inoculation method is more 50% smaller than that of conventional liquid casting of AM60 alloy produced during partial remelting processing. The results are important for practical application because the fine globules in semisolid slurry will favor the flow of the slurry, and produce easily complex parts make the intricate parts. It is a simple processing, and has promising industrial application in the future.