ZLSi7Cu2Mg合金热等静压的工艺研究-材料加工工程专业论文.docxVIP

中北大学学位论文 中北大学学位论文 万方数据 万方数据 ZLSi7Cu2Mg 合金最佳热等静压工艺方案，其温度和压力参数分别为 450℃,120MPa。 关键词： ZLSi7Cu2Mg 合金，热等静压，流变应力，显微组织，力学性能 Study on Hot Isostatic Pressing Processing of ZLSi7Cu2Mg Alloy Abstract ZLSi7Cu2Mg alloy becomes one of the widely used alloys for industrial applications for it has not only good casting properties but also a good air seal property. Vehicle engine blocks, cylinder heads and other aluminum castings with complex shape or withstanding great loads, so the high mechanical properties of them are required. Eliminating internal casting shrinkage, shrinkage porosity and other inner casting defects is one of the important way to improve casting density and mechanical properties required in application.In this paper, hot isostatic pressing (HIP) technique is applied to achieve this goal, and then we study the HIP processing of ZLSi7Cu2Mg alloy . In this thesis, ZLSi7Cu2Mg alloy as the research object. First of all, the deformation behaviors for ZLSi7Cu2Mg alloy at high temperatures have been investigated, and make four rational HIP technology programs. Further, preparing for the original(non-HIP) and HIP-ed (four technology programs) alloy castings, the analysis methods of metallography,tensile test and fractography were used to compare the performance of the microstructure and summarizes the changes of their microstructure and performances after HIP process. Finally, the mechanical properties of those HIP-ed castings at different technology programs are compared, and then we develop the best HIP technology program of ZLSi7Cu2Mg alloy. The results had been obtained as follows: The flow stress at high temperature of ZLSi7Cu2Mg alloy is related to temperature, strain rate and deformation, accordingly reducing with the increasing in temperature and the decreasing of strain rate. ZLSi7Cu2Mg alloy castings after HIP process can effectively eliminate the microporosity and pinhole defects, especially for thin-walled or smaller size castings. Some pores in the casting