摘要
普通重力铸造法制备了原位自生Mg2Si/Al基复合材料,研究了Mg、Si加入量及热处理对变质处理后的Mg2Si/Al基复合材料的组织影响。结果表明:稀土与锶盐混合变质剂对Mg2Si/Al体系中初生-αA1变质效果好,但对共晶-αA1不明显;含较多过量Si的亚共晶组成Al-Mg2Si铸态组织中,共晶Mg2Si位于晶界处并呈不完整汉字状,而含Si量少的近共晶组成Al-Mg2Si的凝固组织中的二元共晶Mg2Si长成完整分枝多的汉字状,并为-αA1所包围;热处理使三元共晶Mg2Si细化为点状,使二元共晶Mg2Si转变为细小的点状或棒状,也使高熔点初生Mg2Si产生一定的熔细现象,颗粒尺寸从约15μm降至8μm左右。
In - situ Mg2Si reinforced Al alloy composites were fabricated by common weight casting technique. Effects of different Mg and Si content and heat treatments on microstructures of materials were studied. The results indicate that the effect of combined modification of rare earths and Strontium salt on primary α-Al is very good, while not obvious on eutectic α-Al. Eutectic Mg2Si nucleates at crystal boundaries, with shaping undeveloped Chinese characters-like in a hypoeutectic Al-Mg2Si system which contains more Si element, while eutectic Mg2Si is surrounded by α-Al and grows to integrated Chinese characters-like shape in a nearly eutectic Al-Mg2 Si system in which little Si contained. Eutectic Mg2Si is refined to particles or short coshes in a heat treatment process, and the size of primary Mg2Si is also reduced at some extent, from about 15 μm to 8 μm.
出处
《轻合金加工技术》
CAS
北大核心
2007年第10期44-46,50,共4页
Light Alloy Fabrication Technology
