铸模温度对牙用Ti-Zr合金铸造后力学性能影响的研究  

Effect of Mold Temperature on Mechanical Properties of Ti-Zr Alloy Castings

作　　者：张玉梅 郭天文 沈丽娟 李佐臣[2] 

机构地区：[1]第四军医大学口腔医院修复科,陕西西安710032 [2]西北有色金属研究院,陕西西安710016

出　　处：《华西口腔医学杂志》2004年第6期516-518,共3页West China Journal of Stomatology

基　　金：国家自然科学基金资助项目 (39770 80 5)

摘　　要：目的　观察铸模温度对牙用Ti_Zr合金铸造后力学性能的影响。方法　在 3种铸模温度下 ,对牙用Ti_Zr合金铸造后的抗拉强度、屈服强度和延伸率 3种力学性能指标进行测试 ;同时采用金相显微镜观察 3种铸模温度下的铸件的显微组织结构。结果　随着铸模温度的升高 ,Ti_Zr合金的抗拉强度及屈服强度均增高而延伸率下降。Ti_Zr合金的显微金相组织结构显示 ,随着铸模温度的升高 ,表面污染层逐渐增厚 ,室温时约为 35 .5 μm、30 0℃时约为5 5 .0 μm、6 0 0℃时约为 6 5 .5 μm ;铸件边部与中心部的显微结构不同 ,铸件边部从表面向基体形成粗大的树枝状α片 ,而中心部为等轴的α晶粒。结论　铸模温度影响Ti_Zr合金铸件的显微结构 ,从而使Ti_Zr合金铸造后的力学性能发生改变 ;Ti_Zr合金铸造后的力学性能 ,能够满足临床义齿支架合金的性能要求。Objective To investigate the influence of mold temperature on the mechanical properties of Ti-Zr alloy castings.Methods Ti-Zr alloy was cast into a mold which was made of a zircon ( ZrO-2·SiO-2) investment with a casting machine (China) designed as vacuum, pressure and centrifuge. At three mold temperatures (room temperature, 300 ℃, 600 ℃) the Ti-Zr alloy was cast separately. The ultimate tensile strength (σ-b ), 0.2% offset yield point strength (σ-{0.2}), and elongation to fracture (δ) were determined by a universal testing machine with 15 mm pre-marked gauge interval. The surface micro-structures of Ti-Zr alloy castings at three mold temperatures were observed by optical microscope.Results At a higher mold temperature during casting, the tensile strength and yield strength of Ti-Zr alloy were significantly increased, while the elongations were significantly decreased. The micro-structure of the surface was different from the inner part. There was a reacted layer in the outermost surface. The thickness of reacted layers at the three mold temperatures was about 35.5 μm (room temperature), 55.0 μm (300 ℃) and 65.5 μm (600 ℃), respectively. The inner part of microstructure composed of main α phases within the prior α grain boundaries.Conclusion The mold temperature is one of the major factors influencing Ti-Zr alloy mechanical properties. Comparing with Ti6Al4V alloy and Co-Cr alloy castings, Ti-Zr alloy is more suitable for denture frame.

关 键 词：TI-ZR合金 铸造 力学性能 

分 类 号：R783.1[医药卫生—口腔医学]