Development of Thermal Shock Testing System for Functionally Graded Materials

为评价功能梯度材料(FGM)的热冲击性能，研制了一套集自动化和多功能于一体的燃烧器加热试验系统。在新开发的系统中，通过用燃烧器火焰加热陶瓷表面，并用气体或水冷却底部表面(通常是金属)，可以系统地研究功能梯度材料试件的热机械性质。确定了燃烧器输出功率与顶面温度、底面温度和平均热流密度的关系。利用损伤萌生和扩展过程中释放的声发射信号监测热冲击损伤。通过逐步增加烧嘴的输出功率，重复加热和冷却循环，直到检测到较大的损伤。为了评价粉末冶金制备的功能梯度材料的热机械性能，进行了烧嘴加热试验，例如在SiCAlN/Mo、AlN/W、PSZ/不锈钢系统中。研究表明，利用该系统可以确定功能梯度材料设计所需的抗热震性能和隔热性能。

A burner heating test system for evaluating thermal shock behavior of Functionally Graded Materials (FGM) has been developed, which has well-combined automatic and multi-functions. Thermomechanical properties of a FGM specimen can be systematically investigated by heating the ceramic surface with burner flame and coolong the bottom surface (usually metals) with gas or water flow in the newly developed system. The top and bottom surface temperatures and the average heat flux were determined as a function of the power output of burner. Thermal shock damage was monitored with acoustic emission signals liberated from damage initiation and propagation. By increasing the output power of burner stepwisely, a cycle of heating and cooling was repeated until a large damage was detected.The burner heating tests have been carried out for evaluating the thermomechanical performance of Functionally Graded Materials (FGMs) fabricated by powder metallurgical process, such as in the SiC-A1N/Mo, A1N/W,PSZ/Stainless steel systems. It has been clarified that the properties including thermal shock resistance and thermal insulation, which is needed for the design of the FGM materials, can be determined using the developed system.