稀土元素Y对变形镁合金ZK60的组织和性能的影响

在中世纪有5种重要的真理理论,分别是坎特伯里的安瑟尔谟的真理理论、彼得.阿伯拉尔的真理理论、托马斯.阿奎那的真理理论、基于指代思想的真理理论和14世纪的真理语义理论。"正直"这个概念刻画了安瑟尔谟的真理理论,"dicta"是阿伯拉尔真理理论中的真值承担者,托马斯.阿奎那维护根据理智与客观事物之间的相等来获得真理的方法,基于指代思想的真理理论反对通过形而上学的方法获得真理,14世纪的真理理论认为通过语义方法获得真理,并且引入了对命题指代的量化。

Influence of rare - earth element Y on microstructureand mechanical properties of ZK60 magnesium alloys

Abstract: Based on microstructure analysis and mechanical p roperty research of the samp le ofmagnesium alloy, Mg - 6. 0Zn - 1.2Y andMg - 6. 0Zn - 0. 6Zr - 1. 0Y, which experienced squeezing and heat treatment, this paper discussed the existence form of rare- earth element Y in ZK60 alloy and the influence of its actingmechanism onmicrostructure and mechanical p roperty of this alloy. Theresult shows that rare - earth element Y can make grain refinement and crystal boundary refinement of ZK60 magnesium alloy and that,when the amount of added rare - earth element Y is 1. 0% wt, a lof of Y and Zn are enriched at crystal boundary, Y - Zn phase grainbecomes larger, as a result, the intensity of the alloy decreases and the extensibility increases.