大尺寸复杂筒状铝合金精铸件浇注系统设计方法研究

研究大尺寸复杂筒状铝合金精铸件浇注系统的设计方法,通过对三种具有筒状结构的大尺寸复杂铝合金精密铸件的浇铸系统设计和浇注试验,研制出冶金质量和力学性能合格的铸件。结果表明,缝隙式浇注系统或缝隙式与底注式相结合的浇注系统是该类铸件比较理想的浇铸系统设计方式。

大型筒状薄壁钛合金铸件变形预防及工艺改进

主要研究了大型筒状薄壁钛合金铸件铸造工艺对变形的影响以及变形预防改善措施,结果表明:浇注系统采用开放式分散均布多层充型方案,热等静压时铸件平放并避免叠压碰撞,补焊时用工装支撑并减小输入电流和多次分散逐层焊接可有效预防薄壁圆筒形铸件在铸造过程中的变形;对轻微变形的筒状钛合金铸件采用仿形工装、热法校正工艺进行挽救,检测结果满足技术要求可以使用。通过优化大型筒状薄壁钛合金铸件铸造工艺,同时实施预防变形及校正等措施,提高了铸件一次合格率。

Formation mechanism and criterion of linear segregation in ZL205A alloy

The experiments and numerical simulation were conducted for ZL205A aluminum alloy cylindrical shell casting. The formation mechanism of the linear segregation produced by the low pressure die casting (LPDC) process was investigated. And the heat transfer of the casting during solidification process was analyzed by simulation technique, resulting from the information of linear segregation obtained by plenty of experiments. The new linear segregation criterion was proposed through the simulation and experimental results. It was found that the melting metal with high Cu contents was feeding the crack shrinkage formed by the tearing under the effect of feeding pressure during the later solidification, which led to the formation of linear segregation. The control methods for the linear segregation were suggested based on the proposed mechanism. Finally, the criterion of linear segregation was confirmed by the production of the actual castings.

轮边减速器壳制芯工艺开发

轮边减速器壳为带法兰筒状结构,其特点是高径比大、壁薄,制芯工艺设计难度较大。本文根据产品结构特点、铸造工艺要求和产品生产批量,开发了制芯镶嵌冷铁和中抽空相结合的冷制芯工艺,研制出轮边减速器壳专用冷芯机,实现了制芯机械化,解决了静压铸造生产线砂系统不平衡问题,满足了大批量生产的要求。