摘要
研究了B对Mg-7Al-0.4Zn-0.2Mn合金显微组织和力学性能的影响。结果表明:加入微量的B就能使合金的晶粒得到显著的细化,并且随着B加入量的增加,细化效果越明显,当B的加入量(质量分数,下同)为0.15%时,平均晶粒尺寸由未变质合金的约140μm细化到约40μm。分析认为:具有密排六方结构的高熔点化合物AlB2可作为α-Mg的异质核心,从而细化镁合金晶粒。微量B的加入使铸态合金的力学性能得到不同程度的提高,当B的加入量为0.15%时,合金的显微硬度、抗拉强度和屈服强度分别比未变质合金提高13.1%、19.5%和22.0%,冲击吸收功约为未变质合金的2.3倍。B的加入量为0.10%时,合金的伸长率比未变质合金提高21.6%。
Effects of B on microstructure and mechanical properties of Mg-7Al-0.4Zn-0.2Mn alloy were investigated.It was found the as-cast microstructure and average grain size are remarkably refined with trace B addition,exhibiting more strongly refining effects with increase of the B content.The average grain size was decreased from about 140μm without B alloy to 40μm with 0.15% B addition.It was concluded that the grain size was refined due to the high melt point compound AlB_2 with HCP crystal structure serving as the heterogeneous nuclei site.The mechanical properties of the as-cast alloys are increased with trace B addition.The microhardness,tensile strength and yield strength of the alloy with 0.15% B addition were increased by 13.1%,19.5% and 22.0%,respectively,comparing with those of the alloy without B addition,and the energy to fracture is 2.3 times than that of the alloy without B addition.Elongation of the alloy with 0.10% B content is increased by 21.6% comparing with that of as-cast alloy.
出处
《特种铸造及有色合金》
CAS
CSCD
北大核心
2005年第8期454-456,共3页
Special Casting & Nonferrous Alloys
基金
河南省高校创新人才工程资助项目(豫2001-6)
河南省科技攻关资助项目(0224360015)
