摘要
利用OM、XRD、SEM和EPMA等手段研究了Al-3Ti-3B细化剂对AZ31镁合金微观组织的影响。结果表明,添加适量的Al-3Ti-3B细化剂能使铸态AZ31镁合金粗大的树枝晶转变为均匀的等轴晶;加入量为0.4%时取得了较好的细化效果,固溶处理后的AZ31镁合金平均晶粒尺寸由300μm减小到50μm。TiB2和AlB2粒子的异质形核作用是促使晶粒细化的主要机制,且TiB2粒子在晶界上的偏聚可进一步阻碍晶粒长大。
Effects of Al-3Ti-3B master alloy on grain refinement of AZ31 magnesium alloy were observed by OM （optical microscope）, XRD （X-ray diffraction）, SEM （scanning electron microscope） and EPMA. The results reveal that coarse dendrite is transformed into uniform equiaxed grain in the as-cast AZ31 alloy with proper Al-3Ti-3B master alloy. Desirable refining effects can be observed in the alloy with 0.4% Al-3Ti-3B alloy. Average grain size in solid solution treated AZ31 alloy is refined from 300 μm to 50 μm. Grain refinement is mainly controlled by creation of TiB2 and AlB2 particles as heterogeneous nuclei, and aggravation of TiB2 phase at the grain boundary can further restrain the growth of the primary Mg phase.
出处
《特种铸造及有色合金》
CAS
CSCD
北大核心
2011年第6期491-495,共5页
Special Casting & Nonferrous Alloys
基金
国家高技术研究发展计划(863计划)资助项目(2009AA03Z525)
大连市科学技术基金资助项目(2009J21DW003)
