铋含量对原位自生Mg2SiAZ91D复合材料组织与性能的影响.pdf

第6卷第3期
有色金属工程
2016年6月
Nonferrous Metals Engineering
lune 2 6
doi:10.3969/.issn.2095-1744.2016.03.006
含量对原位自生Mg2Si/A91D复合
材料组织与性能的影响
陈淑英,邵秉川,陈智麟,常国威
(辽宁工业大学材料科学与工程学院,辽宁锦州121001)
摘要:制备原位自生M82SiA791D复合材料,研究变质剂含量对复合材料组织与力学性能的影响。结果表明,加人铬变质
剂后,原位自生Mg2SiAZ91D复合材料中初生相Mg2Si由粗大的树枝状变成细小的多边形状和颗粒状,共晶相Mg2Si由汉字状变
成短棒状和虫状,MB1A12相由连续网状分布变成弥散板条状分布。鉍含量为0.8%时,初生相Mg2Si最细小,平均晶粒尺寸为
13Wm,比未変质时减小了81%。铋含量为0.8%时Mg2Si/A291D复合材料力学性能最佳,抗拉强度和延伸率分别为290MPa和
7%,比未变质时分别提高25.5%和109%。
关鍵词:Mg2Si/AZ91D复合材料;嵌含量;カ学性能;原位自生;初生相Mg2Si
中图分类号:TB33312;"TG146.22;TG113文献标志码:A文章编号:2095-1744(2016)03002105
Influences of Bi Content on Microstructure and Mechanical
Property of In-situ Mg, Si/AZ91D Composites
ng, SHAO Bing-ch
CHEN Zh
CHANC Guo-wei
School of Materials Science and Engineering, Liaoning University of
echnology
ng 121001, China)
Abstract: The in-situ Mg, Si/AZ91D composite is prepared and the influences of the content of Bi
modifier on the microstructure and mechanical properties of the composite is investigated. The results
show that the shape of the primary phase Mg, Si in in-situ Mg, Si/AZ91 D composite is transformed into the
tiny polygon or particle from the thick arborization, the shape of the eutectic Mg, Si is transformed into the
short rod and vermicular from Chinese script type and the distribution of Mg,, Alp is transformed into
dispersed plate strip distribution from continuous mesh distribution. When the content of Bi is O8%, the
primary phase Mg Si is the smallest and the average size of the grain is 13 wm and decreased by 81%
compared with without solidification. The mechanical properties of M Si/AZ91 D composite are the best
when the content of Bi is 0.8%. The tensile strength and the elongation are 290 Mpa and 6.7%
respectively, and increased by 25 5G and 109% compared with without solidification
Key words: M, Si/AZ91 D composites; Bi content; mechanical property; in-situ; primary
hase Mg, Si
与传统的金属材料相比,镁基复合材料由于具镁基复合材料由于制备工艺简单、易机械加工等优
有高的比强度、比刚度、耐高温、热膨胀系数小、化学点,成为最有可能实现低成本、规模化生产的镁基复
稳定性好等优异性能,成为继铝基复合材料之后又合材料。Mg2Si具有低密度、嫆点高、硬度高、热膨
一具有竞争力的轻金属基复合材料12。颗粒增强胀系数小、能够在镁基体中通过原位反应生成等优
点,成为镁基复合材料中良好的增强体341。
收稿日期:2015-09-14
Mg2Si增强体的形态、尺寸与分布是决定
基金项目:近宁省高等学校杰出青年学者成长计刘项目Mg:SMg-A1复合材料性能的重要因素。在传统的
作者简介:陈淑英(1974-),女,满族,辽宁锦州人,副教授,博士,主铸造条件下,初生相Mg2Si呈粗大的树枝状,而共晶
要从事金属凝固理论与控制凝固技术等方面研究。
相Mg2Si呈汉字状,这两种形态的Mg2Si严重割裂