新型医用Mg-Zn-Mn-Y镁合金的热变形及生物降解行为研究

IMR OpenIR

	新型医用Mg-Zn-Mn-Y镁合金的热变形及生物降解行为研究
	何维维
学位类型	博士
导师	杨柯 ; 张二林
	2010
学位授予单位	中国科学院金属研究所
学位授予地点	北京
学位专业	材料加工工程
关键词	镁合金生物医用材料热压缩动态再结晶生物腐蚀
摘要	Y元素的加入有明显细化铸态镁合金晶粒的作用，但当Y增加到1.54wt.%时，细化晶粒的作用减弱,I相对合金的强化作用优于W相，而W相对镁合金的韧化作用强于I相。挤压态Mg-Zn-Mn-Y合金表面除磷酸盐外，生成了具有保护性的Y2O3薄膜,Y元素可以降低镁合金的阴极电流密度，提高电荷转移电阻和膜电阻，降低镁合金双电层的电容值。Mg-Zn-Mn-0.36wt.%Y合金I，变形量较小时，以常规动态再结晶为主，较大变形量时为连续动态再结晶。Mg-Zn-Mn-1.54wt.%合金时，变形量较小时的动态再结晶方式为连续动态再结晶，变形量较大时为旋转动态再结晶。Mg-Zn-Mn-0.36wt.%Y合金在高温下变形可获得均匀细小再结晶晶粒；Mg-Zn-Mn-1.54wt.%合金在高温下变形时，晶粒长大，细化晶粒要依靠增大变形量。
其他摘要	"Study on microstructures of as-cast Mg-Zn-Mn-Y alloys showed that when Y content was increased from 0.36% to 0.82 wt. %, reduction in grain size in the alloys was more significant than those with Y content increased from 0.82% to 1.54wt.%. I-phase had better strengthening effect than that of W-phase, while softening effect of W-phases was superior to that of I-phase. It was found that a protective Y2O3 film was formed on the surface of magnesium alloys due to the addition of Y element. OCP, polarization test and EIS results firmly indicated that Y element decreases the cathodic current density, improves the charge transfer and film resistances, and reduces the double layer capacity of Mg-Zn-Mn alloy. when true strain was low, DRX mechanism of Mg-Zn-Mn-0.36wt.%Y alloy was normal as the ordinary DRX, and DRX mechanism of Mg-Zn-Mn-1.54wt.% alloy was continuous DRX,When the true strain was high , the DRX mechanism of Mg-Zn-Mn-0.36wt.%Ywas a continuous DRX, and DRX mechanism of Mg-Zn-Mn-1.54wt.% alloy rotation DRX. For Mg-Zn-Mn-0.36wt.%Y alloy, grain size of DRX was decreased with deformation temperature increased but for Mg-Zn-Mn-1.54wt.% alloy, DRX grain growed abnormally. Microstrucrure of Mg-Zn-Mn-1.54wt.% alloy after deformation could be refined efficiently by increasing the strain."
文献类型	学位论文
条目标识符	http://ir.imr.ac.cn/handle/321006/64191
专题	中国科学院金属研究所
推荐引用方式 GB/T 7714	何维维. 新型医用Mg-Zn-Mn-Y镁合金的热变形及生物降解行为研究[D]. 北京. 中国科学院金属研究所,2010.