论文部分内容阅读
稀土元素以其特有的性能而广泛被应用于微合金化领域。通过对ZL205A合金添加微量元素Y和Zr,采用OM,SEM和EDS等分析测试方法,研究不同含量的Y和Zr对铸态和T5热处理下ZL205A合金微观组织和力学性能的影响。结果表明:添加微量Y和Zr能提高合金的流动性,同时晶粒被明显细化,当添加量为0.1%(质量分数)(Zr 0.05%+Y 0.05%)时,流动性和晶粒被细化效果达到最佳状态,随着Y和Zr含量继续增加,对基体晶粒的细化效果减弱,晶间析出相增多,流动性提高的趋势降低,合金的充型能力下降,力学性能和延伸率呈下降趋势,合金表现为沿晶脆性和穿晶韧性的混合断裂方式;T5处理后,合金中部分微观偏析被消除,抗拉强度和硬度增大,但时效析出的θ″数量减少,弥散强化效果减弱,延伸率未得到改善。
Rare earth elements with its unique properties are widely used in the field of microalloying. The effects of different contents of Y and Zr on the microstructure and mechanical properties of ZL205A alloy were studied by adding trace elements Y and Zr to ZL205A alloy by OM, SEM and EDS. The results show that the addition of trace amounts of Y and Zr can improve the fluidity of the alloy and the grain size is obviously refined. When the addition amount is 0.1% (Zr 0.05% + Y 0.05%), the fluidity and grain size When the content of Y and Zr keeps increasing, the refinement effect of the matrix grains is weakened, the interphase precipitates increase, the fluidity increase tends to decrease, the filling ability of the alloys decreases, the mechanical properties and The tensile strength and hardness increased, but the amount of θ "precipitated decreased after T5 treatment, the micro-segregation in the alloy was eliminated, Dispersion strengthening effect weakened, elongation has not been improved.