【摘要】 在Al-La合金的自由凝固试样中,发现Al-35%La合金组织形貌的特殊性,其先结晶相Al11La3枝晶沿主干方向成分是不连续的.为验证这种组织存在的真实性,采用定向凝固方法制备了不同冷却速度下的Al-35%La合金试样,结果显示出定向凝固Al-35%La合金中Al11La3枝晶沿主干方向成分是不连续的.在此基础上,分析了化学成分与凝固速度对Al-La合金组织的影响,并初步探讨了这种不连续枝晶的形成机理.更多还原

【Abstract】 Al-La alloy samples with different compositions were prepared by a free solidification method.The results show that the dendrite structure of Al11La3 in an Al-35%La alloy is discontinuous.For demonstrating the authenticity of this structure,adopting a directional solidification method,Al-35%La alloy samples were prepared at different solidification rates.It is indicated that the dendrite structure of Al11La3 in the Al-35%La alloy obtained by directional solidification is discontinuous.The effects of composition and solidification rate on the microstructure of Al-La alloys were analyzed,and the formation mechanism of the discontinuous dendrite structure was discussed preliminarily.更多还原