Study On Mechanical Properties Stability Of Intergrated Casting Of ZL114A Alloy

For the purpose of improving the performance of ZL114A alloy used in aerospace,effects of major element and microelement content on the performance of ZL114A alloy were investigated. Meantime,this paper also investigated the effects of refinement and modification on the microstructure and properties of multi-steps samples and attached test coupon. On this basis,the performance of ZL114A alloy was improved through technique optimization.The results indicated that tensile strength and yield strength of ZL114A alloy increased with the increase of Si content,whereas,the elongation of the alloy decreased sharply. The effects of Mg and Cu content on the tensile strength of ZL114A alloy can be ignored,otherwise,the yield strength of ZL114A alloy increased with the increase of Mg and Cu content,and the elongation of the alloy decreased with the increase of Mg content,nevertheless,the effect of Cu content on the elongation of ZL114A alloy can be ignored.In experiment of AlSr10 master alloy modification and Al-Ti-B refinement,the best comprehensive mechanical properties was obtained at 0.04wt% Sr and 0.2wt%Ti. Compared to the ternary sodium salt modification and AlTi4BA refinement,the tensile strength and yield strength of multi-steps samples and attached test coupon modified by AlSr10 master alloy were higher,whereas,the elongation of the attached test coupon was lower. However,the elongation divergence of ternary sodium salt modification was small and the elongation was steady.In the analysis of thick wall of shell casting,the large thermal capacity of thick wall resulted in low cooling rate and coarse structure,and the morphology of Si was acicular and flake like,as a result,the performance of shell casting was lower. However,the performance of thick wall can be enhanced by chilling,content of Mg and Si adjustment,modification and refinement as well as low pressure pouring and heat treatment optimization.