梯度功能陶瓷圆球的抗热震性  

THERMAL SHOCK RESISTANCE OF FUNCTIONAL LY GRADIENT CERAMIC SPHERES

作　　者：赵军[1] 艾兴[1] 李艳征[1] 

机构地区：[1]山东大学机械工程学院,济南250061

出　　处：《硅酸盐学报》2006年第11期1362-1366,共5页Journal of The Chinese Ceramic Society

基　　金：国家自然科学基金(50105011);全国优秀博士学位论文作者专项资金(200231);高等学校博士学科点专项科研基金(20050422033)资助项目。

摘　　要：推导和提出了第三类边界条件下梯度功能材料(functionally gradient materials,FGM)圆球的瞬态温度场及瞬态热应力场表达式。基于陶瓷材料的临界应力断裂判据,通过求解梯度功能陶瓷圆球表面达到其局部断裂强度的时间,建立了引起其表面临界热应力的临界温差?Tc的表达式,并以此作为梯度功能陶瓷圆球的抗热震参数。通过计算实例并与均质陶瓷圆球对比,分析了材料的热–物理性能分布规律对其抗热震性的影响,并提出了高抗热震性FGM陶瓷圆球的设计原则线膨胀系数和热扩散率应由表及里增大,而弹性模量应由表及里减小。The formulae of the unsteady temperature field and thermal stress field for functionally gradient material （FGM） spheres under convective boundary conditions were derived. Based on the critical stress fracture criterion and by means of the calculation of the time for the surface of FGM ceramic spheres to attain their local fracture strength, the expression of the critical temperature difference ATe leading to the critical thermal stress at the surface as the thermal shock resistance parameter for FGM ceramic spheres was obtained. The effects of the thermo-physical properties on the thermal shock resistance of FGM spheres were analyzed via numerical calculations in contrast to homogeneous ceramic spheres, from which some design principles for FGM spheres with high thermal shock resistance were proposed.

关 键 词：梯度功能材料 抗热震性 临界温差 非稳态热应力 

分 类 号：TQ174.75[化学工程—陶瓷工业]