Zr和 Mg对快速凝固Cu-Cr合金时效析出过程的影响

Effect of Zr and Mg on the Aging Precipitation of Rapidly Solidified Cu\|Cr Alloy

快速凝固ＣｕＣｒ和ＣｕＣｒＺｒＭｇ合金经时效处理后显微硬度显著升高，在５００℃时效后，ＣｕＣｒ合金的硬度峰值为２０６ＨＶ，ＣｕＣｒＺｒＭｇ合金的硬度峰值为２５０ＨＶ。用透射电镜对两种合金时效过程中析出相的变化及其对显微硬度的影响进行了分析。ＣｕＣｒ合金达到峰值硬度时析出相为与母相共格的面心立方Ｃｒ，随后逐渐与母相失去共格关系并转变成体心立方的Ｃｒ。ＣｕＣｒＺｒＭｇ合金对应峰值状态的析出相为Ｈｅｕｓｌｅｒ相ＣｒＣｕ２（ＺｒＭｇ）。

The microhardness of rapidly solidified Cu\|Cr and Cu\|Cr\|Zr\|Mg alloys are notably enhanced due to aging treatment.The peak microhardness upon aging at 500?℃ for Cu\|Cr and Cu\|Cr\|Zr\|Mg alloys are 206HV and 250HV,respectively.The changes of aging precipitates were observed by TEM and their effects on the microhardness were analysized.For Cu\|Cr alloy,the precipitates corresponding to the peak hardness are matrix coherent fcc Cr,which gradually loses the coherent relation with the matrix upon aging at higher temperatures.For Cu\|Cr\|Zr\|Mg alloy,the precipitates corresponding to peak hardness are Heusler phase CrCu\-2(ZrMg),which change to fcc Cu\-5Zr and bcc Cr upon further aging.Effect of Zr and Mg o