TC4钛合金热氧化层微米压痕/划痕试验研究
Study on Micro-indentation and Micro-scratch Experiment of Thermal Oxidation Coating on TC4 Alloy
张春艳 1王振林 1田中青 1杨惠1
作者信息
- 1. 重庆理工大学材料科学与工程学院,重庆,400050
- 折叠
摘要
采用微米压痕实验测试了氧化层的硬度、弹性模量,研究了热氧化工艺对TC4钛合金表面热氧化层力学性能的影响;通过微米划痕实验考察了氧化层的临界荷载以及划擦行为.结果表明:热氧化处理后TCA表面生成由金红石TiO_2和少量Al_2O_3所组成的氧化层,钛合金表面硬度和弹性模量显著增加,弹性模量与硬度的比值降低,表明热氧化工艺可改善钛合金的耐磨性.长时间的高温氧化可以增加氧化层的厚度,但在划擦过程中氧化层发生两次脱落,表明氧化层由外表层和次外层组成,外层结合力差,易发生一次脆性剥落.内层与基体的结合强度较高,但在较大载荷作用下会产生微裂纹,导致氧化层的二次剥落.
Abstract
An oxide layer was produced on the surface of TC4 alloy by thermal oxidation process to improve the tribological properties of titanium alloy. The Young's modulus (E) and hardness of oxide layer were measured by micro-indentation. The effects of thermal oxidation on the mechanical properties of thermal oxidation coating were studied. The scratch resistance and damage behaviours of the oxide layer were evaluated using micro-scratch techniques. The results show that the oxide layer on TC4 alloy surface is multi-layered oxide consisting of predominant TiO_2 and Al_2O_3. Thermal oxidation treatment can increase the surface hardness and elastic modulus significantly and reduce the E/H ratio of the TC4, which indicate the treatment can enhance the wear resistance of TC4 alloy. Long time treatment can increase the thickness of the oxide layer, but the outside layer is apt to desquamate during the scratching. The oxide layer closing to substrate has better bonding properties, but microcrack forms as a result of high stress loading, which lead the layer to flake off completely.
关键词
TC4/热氧化层/微米压痕/微米划痕/力学性能Key words
TC4/thermal oxidation coating/micro-indentation/micro-scratch/mechanical properties引用本文复制引用
出版年
2009
NETL
NSTL
维普
万方数据