铸模的冷却方式对牙科纯钛铸件的力学性能影响的研究  

Effect of two types of cooling ways on the mechanical properties of dental titanium castings

作　　者：闫澍[1] 张玉梅[2] 施生根[1] 牛忠英[1] 卢怡[1] 史亮[1] 

机构地区：[1]解放军第三零六医院全军口腔疾病诊治中心 [2]解放军第四军医大学附属口腔医院修复科

出　　处：《口腔颌面修复学杂志》2012年第3期171-174,共4页Chinese Journal of Prosthodontics

摘　　要：目的:观察不同的铸模冷却方式对牙科纯钛铸造后力学性能的影响。方法:在冷水和自然冷却两种铸模冷却方式下,对牙用纯钛铸件的抗拉强度、屈服强度和延伸率3种力学指标进行测试;采用金相显微镜和扫描电镜观察铸件的显微组织结构及断口形貌。结果:牙科纯钛在铸造后冷水组的抗拉强度和屈服强度均高于自然冷却组,而延伸率低于自然冷却组。显微组织结构显示冷水组和自然冷却组中均可见晶粒粗大的片层状组织,冷水组的晶粒相对细小,但条索状α相交错排列。断口扫描电镜分析显示自然冷却组与冷水组相比韧窝大而深。结论:为使牙科纯钛铸件拥有更好的塑性,铸造完成的铸模宜采用自然冷却方式。Objective： To investigate the influence of different cooling ways on the mechanical properties of dental titanium castings.Methods： The ultimate tensile strength（σb）,0.2% offset yield point strength（σ0.2）,and elongation to fracture（δ） which had been water cooled and nature cooled were surveyed by a universal testing machine with 15mm pre-marked gauge interval.The appearances of incision of the broken samples were investigated with scanning electron microscope.The center microstructures of the unbroken samples were determined by metallurgical microscope.Results： The ultimate tensile strength（σb） and 0.2% offset yield point strength（σ0.2） of the samples in watter cooling group were higher than in nature cooling group,while the elongation to fracture（δ） was lower than the latter.The microstructures showed that both groups were principally composed of lamellar grains which were grosses.The grains of watter cooling group were relatively diminished,but there were explicit funicular criss-cross α-phase in the group.Scanning electron microscope showed that the appearances of incision of the nature cooling group apparently had bigger and deeper tenacious microbores than the water cooling group.Conclusion： In order to enhance plasticity of the titanium castings,casting moulds should be nature cooled after casting.

关 键 词：冷却方式 牙科纯钛 铸造 力学性能 

分 类 号：R783[医药卫生—口腔医学]