摘要
本文用SEM研究了一系列ZrO2增韧AT30金属陶瓷(也称AT30Z),在不同冲蚀速率及冲蚀角组合条件下的冲蚀形貌及流失机制;结果表明:随垂直入射动能增大,材料表面相继出现应力疲劳→晶粒剥离→应变疲劳及高角铲削的冲蚀机制的过渡交换,各机制的法向速度门槛值Va、Vb和Vc与靶材的断裂韧性Kc等靶材性质有关,而与冲速率及冲蚀角无关.本文建立了冲蚀速度座标系,以综合分析冲蚀速率及冲蚀角对冲蚀的影响,分析结果与SEM观察吻合.
n this paper the eroded Surface morphology of a series of zirconia toughende AT30Z cermets samples by SEM at different erosive situations was investigated. The test resultsshowed that: with increase of normal component of impact energy En, erosion mechnnismstransition were observed correspondently: stress fatigue(low En ), radial cracking and graindispartching (medium En ), strain fatigue and shoveling(high En) ;Threshold normal components of impact energy of the above -- mentioned mechanisms (Ea,Eb and Ec ) were relatedwith fracture toughness Kc, hardness ration Hp/Ht, however appeared little relation withimpart velocity and angle. A zoned Vn -- Vt rectangular coordinates system was plotted tocover influence of impingement velocity V and angle a on erosion mechanism, A comprehensive erosion rate equation was derived for AT30Z ceramic series by means of elastic-- plasticmechanics and fracture mechanics analysis which could explain the ε -- α curves and ε -- Vcurves from the ceramics well.
基金
国家自然科学基金
关键词
金属陶瓷
冲蚀
应变疲劳
裂纹
冲蚀速度
SEM
AT_(30)Z cermets
erosion
erosion velocity
strain fatugue
radial crack