【作者】 邱龙时； 马胜利； 徐可为；

【Author】 Longshi-Qiu;Shengli-Ma;Kewei-Xu;State-Key Laboratory for Mechanical Behavior of Materials, Xi’an Jiaotong University;

【机构】 西安交通大学金属材料强度国家重点实验室；

【摘要】 用多弧离子镀(MAIP)技术在高速钢基体上沉积了TiN硬质镀层,采用接近实际工况使用条件的滚动接触疲劳法(RCF)对镀层的结合性能及失效行为进行了系统评价,重点研究了滚动接触条件下镀层的疲劳失效机制及定量评价方式。结果表明:在滚动接触测试条件下,TiN镀层剥落方式为结合力型失效剥落,而未出现内聚型失效剥落。在相同加载情况下,随着TiN镀层厚度由1.6μm增加到3.7μm,作用于膜基界面处的剪切应力幅增加,镀层失效临界疲劳周次减少。根据Hertz弹性理论计算得到镀层界面处剪切应力幅与疲劳周次的裣τ-N关系曲线,结果发现裣τ-N曲线出现循环轻载长周期和循环重载短周期两个不同阶段。本文研究证实,相对于压入法或划痕法,滚动接触疲劳法的裣τ-N曲线能更有效评价定量评价硬质镀层的结合性能。更多还原

【Abstract】 TiN hard coatings were deposited on high speed steel(HSS) substrates by multi- arc ion plating(MAIP) technology. Then rolling contact fatigue(RCF)– a method much more closed to actual working conditions was used to evaluate the adhesion of the coatings. The present study was emphasis on the failure mechanism of the coating under the condition of rolling contact fatigue and the method for quantitative evaluation.Results indicated that theTiN coatings peeled off from substrates were adhesive failure rather than cohesive failure. According to the Hertz elastic theory, shear stress amplitude at the interface was obtained. Under identical loading conditions, with the thickness of TiN coatings increased from 1. 6μm to 3. 7μm, the shear stress amplitude was enlarged while critical fatigue cycle was reduced. Two distinct stages were emerged in curves of shear stress amplitude and fatigue cycle(裣 τ- N), heavy load with short cycles and light load with long cycles, respectively. Furthermore, through experiments it was proved that compared with traditional indentation method and scratch method, the rolling contact fatigue has provided a more effective way to evaluate the adhesive strength of the hard coatings quantitatively.更多还原