【摘要】 研究了熔体分散混合法制备的半固态浆料初生相形成过程。通过对浆料组织EPMA和金相组织层剥离等试验、熔体分散混合工艺处理熔体的过冷度测定,描述了球状初生相的形成机制。结果表明,熔体在制浆室内均匀过冷,大量的晶核在过冷熔体中以非自发形核的机制形成,均匀分布在熔体中,并且在过冷熔体中被保留下来,成为有效晶核,继而生长成为球状初生相。更多还原

【Abstract】 The nucleation behavior of primary phase in semi-solid slurry prepared by melt spreading and mixing technique(MSMT)was analyzed.By determining undercooling degree of melt prepared by MSMT,measuring the distribution elements in primary phase particles with EPMA and the experiment obtained 3Dimages by serial-sectioning technique,formation mechanism of globular primary microstructure under melt spread and mixed condition was discribed.When the melt is cooled below liquidus by processing in making-slurry chamber,heterogeneous nucleation takes place in the liquid alloy to uniformly distribute in the melt and retain in the super-cooled melt to form effective nuclei,and then it is grown into the globular phase.更多还原