不同热处理方式对Ti-6Al-7Nb合金疲劳强度影响的实验研究  

Influence of heat-treatment on fatigue strength of casting Ti-6Al-7Nb alloy

作　　者：崔敏[1] 朱娟芳[2] 何惠明[1] 

机构地区：[1]第四军医大学口腔医学院,陕西西安710032 [2]郑州大学第一附属医院,河南郑州450002

出　　处：《牙体牙髓牙周病学杂志》2009年第5期286-289,293,共5页Chinese Journal of Conservative Dentistry

基　　金：陕西省工业攻关基金资助项目(2006K06-G8)

摘　　要：目的:研究不同热处理方法对铸造Ti-6Al-7Nb合金疲劳强度的影响,以探讨提高铸造Ti-6Al-7Nb合金疲劳寿命的最佳热处理方案及其临床可行性。方法:将铸造成符合ASTME466-07疲劳试验标准规格形状的Ti-6Al-7Nb合金铸件分别进行固溶-时效硬化退火(A组),再结晶退火(B组)以及四组等温退火热处理(C1-C4组)。将处理后的试件分别进行拉伸强度试验及拉-拉疲劳试验,记录其拉伸强度和试件断裂时疲劳循环次数。结果:抗拉强度:以固溶+时效硬化组(A)最高,与其他组相比有统计学意义(P<0.05),而其余各组之间差异均无显著性。疲劳寿命:A组最低,与对照组(D)相差不显著(P>0.05),与其他实验组相差均有统计学意义(P<0.05);其次为B组,A、B、D三组均明显低于等温退火C1组(250℃保持)、C2组(300℃保持)、C3组(350℃保持)和C4组(400℃保持),(P<0.05);等温退火C2、C3、C4组的疲劳寿命高于等温退火组C1组(P<0.05)。C2、C3、C4组之间无显著差异(P>0.05)。结论:等温退火300℃～400℃是提高Ti-6Al-7Nb合金疲劳寿命较为理想的热处理方式。AIM ： To investigate the influence of different heat - treatments on the fatigue strength of Ti-6Al-7Nb alloy castings. METHODS： ： The Ti-6Al-7Nb alloy was casted into the shape according to ASTMFA66 - 07 and was performed with different heat - treatments ： annealed at 950 ℃ for 1 h then aged at 560℃ for 2 h as the solution annealing and age harden group （ treatment A） ; annealed at 750 ℃ for 1 h as the recrystallization group （ treatment B ） ; aged at 250 ℃ （ treatment C 1 ）, 300 0（; （ treatment C2 ）, 350 ℃ （ treatment C3 ）. and 400 ℃ （ treatment CA ） for 10 min after treatment B as the isothermal annealing groups. The castings were tested by force - controlled axial fatigue testing method, the loading cycles of the castings and the tensile strength were recorded. The appearances of incision of the broken samples were investigated with scanning electron microscope. RESULTS ： Tensile strength of treatment A was the highest（ P 〈 0.05 ）, and no significant difference showed between the others （P 〉 0.05 ）. Loading cycles of treatment C2, C3 and C4 were the highest and no differences showed between them（P 〈0.05）. Treatment C1 was better than treatment A, B and D（P 〈 0.05 ）. Treatment A and D were the lowest with no significant defference between each other（ P 〉 0.05 ）. CONCLUSION： The isothermal annealing groups including group C2, C3 and CA improve fatigue strength of Ti-6Al-7Nb alloy most significantly during this test.

关 键 词：Ti-6Al-7Nb合金 热处理 疲劳强度 

分 类 号：R783.1[医药卫生—口腔医学]