摘要
氩气下分别采用YG-8硬质合金和硅青铜电极在Ti17表面形成瞬态电能表面强化层，然后用离子束增强沉积铜合金，形成复合强化层。空气介质中在光辐射热疲劳试验机上进行热疲劳试验，在不同热循环周次下测量试样的电阻，并用SEM观察了热循环前后的组织。结果表明，复合强化后的强化层中存在气孔和微裂纹，强化层和基体界面处的缺陷相对集中。25℃～500℃热疲劳后，强化层中裂纹的数量和尺寸增加，存在氧化痕迹，但没有剥落现象。强化试样热疲劳后电阻表征的损伤量比未强化试样略大，可近似认为复合强化对Ti17的热疲劳性能影响很小。
The composite strengthened layers are formed on the surface of titanium alloy Ti17 by electrical discharge using hard alloy YG-8 and silicon bronze as electrodes under argon shield, and then silicon bronze alloy is deposited by enhanced ion beam. The thermal fatigue tests are carried out in air atmosphere on the thermal fatigue apparatus＂ heated by ray radiation. The electrical resistances of specimen are measured after the definite number of thermal cycle. The microstructure is analyzed by SEM before and after thermal fatigue. The results indicate that micro-cracks and micro-pore exist in the composite strengthened layers, and defects are concentrated on the interface between the composite strengthened layer and the substrate. After the thermal fatigue in 25℃ -500℃, the amount and size of micro-cracks are increased in the strengthened layer, and the silicon bronze deposition layers are oxidized, however, composite strengthened layers are not break off. Damage evaluated by the relative change of electrical resistance of the specimen with composite strengthened layer is a bit higher than specimen without composite strengthened layer, in other words, thermal fatigue property of Tilt titanium alloy has a little change after composite strengthening.
出处
《有色金属》
CSCD
北大核心
2007年第4期23-26,共4页
Nonferrous Metals
基金
民口配套研制项目(钛合金表面改性技术研究)
关键词
金属材料
钛合金
复合强化
热疲劳
电阻
metal material
titanium alloy
composite strengthened
thermal fatigue
electrical resistance
