精炼工艺对ZL114A合金组织及性能的影响

Effects of Refining Processing on the Microstructures and Mechanical Properties of ZL114A Alloy

为了研究精炼工艺对ZL114A合金组织和性能的影响,分别采用旋转喷除气法和旋转喷吹除气+过滤法对ZL114A合金进行精炼,并浇注试棒进行热处理.利用金相显微镜、扫描电镜、X射线衍射仪、拉伸实验机等对试棒进行组织观察和性能测试.结果表明,在实验条件下,随着除气时间从0、10、20 min ZL114A合金熔体氢含量从0.180μg/g减少至0.035μg/g,合金组织更加致密.除气20 min的ZL114A合金性能为R_m=327.5 MPa,R_(P0.2)=302.5 MPa,A_5=3.75%.将除气20min后的铝熔体分别采用陶瓷片过滤和钢丝棉过滤,组织观察表明夹杂物数量减少.采用钢丝棉过滤合金中易形成片状富Fe相,其性能分别为R_m=328.3 MPa,R_(P0.2)=298.3 MPa,A_5=4.67%;陶瓷片过滤无富Fe相生成,其性能分别为R_m=335.3 MPa,R_(P0.2)=308.5 MPa,A_5=5.1%,陶瓷片过滤效果更好.从而优化出ZL114A合金精炼工艺为旋转喷吹除气时间20 min,陶瓷片过滤.

In order to research the effects of gas content and inclusions on the microstructures and mechanical properties of ZL114 A alloy,rotary impeller degassing,and rotary impeller degassing ＋ filtering has been used to refine ZL114 A alloy,which were cast samples and heat treated,respectively. The microstructures and properties of ZL114 A alloy treated various refining methods were observed and tested by optical metallomicroscope,SEM,XRD and tensile testing. The results show that the gas content of ZL114 A alloy decreased from 0. 18 μg / g to 0. 03 μg /g with increasing of desgassing time from 0 min,10 min,20 min to 30 min,and microstructure more densification.After degassing time 20 min,even prolong desgassing time to 30 min,the gas content keep unchanged. The mechanical properties of ZL114 A alloy were Rm= 327. 5 MPa,R（P0. 2）= 302. 5 MPa,A5= 3. 75%,respectively,for desgassing time of 20 min. The inclusion content of ZL114 A alloy desgassed for 20 min was decreased by ceramic plate and steel wool filtering,respectively. The chip rich Fe phase was formed of ZL114 A alloy by steel wool filtering,and its mechanical properties were Rm= 328. 3 MPa,R（P0. 2）= 298. 3 MPa,A5= 4. 67%. There were not the rich Fe phase in the ZL114 A alloy by ceramic palte filtering,and its mechanical properties were Rm= 335. 3 MPa,R（P0. 2）=308. 5 MPa,A5= 5. 1%. The filtering effect of ceramic plate was better than steel wool of that. The optimizing refining processing for ZL114 A alloy was desgassing time of 20 min,ceramic plate filtering.