【液态铝合金质量控制关键技术的研究】熊艳才.pdf

ADissertationSubmittedto HuazhongUniversityofScienceandTechnology for the Degree of Doctor of Philosophy inEngineering THEKEYTECHNOLOGICALRESEARCHON METALLURGICALQUALITYCONTROLLING OFMOLTENAI-SiALLOYS Ph.D.Candidate:Xiong Yancai Major:Foundy Advisor:Prof.WangWenqing Ass.Advisor:Prof.

及铸件质量较高.而用Na变质时,变质前必须精炼彻底,变质后15～20min浇注为佳.本文试验表明,若Na变质后再次精炼,将引起变质衰退.然而应用Sr变质时,变质前精炼,有助于提高Sr的实收率,消除了Na变质回炉料的影响.变质后精炼有助于缩短Sr变质的潜伏期,并可防止铝液吸氢.在本研究的试验条件下,首次提出了铝液平衡氢分压、氢浓度与不同铸件壁厚针孔度的关系,为炉前检测并预测铸件质量打下基础。将所研究的成果应用于生产中,大幅度提高了复杂铝铸件的质量,铸件合格率由原来的54 提高到91 .为我国的航天事业作出了应有的贡献.关键词:铝:铝合金:精炼:变质.热分析:测氢:气孔.

able;The time of testing process costs only 3 min.This kind of thermal analysis tech- nique,especially the new type thermal analysis cup provided a stable-precise tool for as- sessment of modification degree ofAl-Sialloys on the shop floor.