【摘要】 运用ANSYS软件建立了有限元模型,对直流等离子体喷射制备的自支撑金刚石厚膜在脱离基体前、后的残余应力分别进行了数值模拟。为了使模拟更接近于金刚石膜的真实制备环境,本文取消了以往对金刚石膜或基体内的温度场常作的均匀或线性的人为假设,而采用对从磁控直流等离子体炬内喷射出的射流仿真计算结果。结论如下(:1)金刚石膜脱离基体之前,金刚石厚膜内的热残余应力呈空间应力状态,第一主应力在膜层中心以外的大部分地方均为拉应力,易引起膜开裂破坏;膜/基界面上极大的剪切应力是引起金刚石膜从基体上脱离的主要原因。(2)金刚石膜脱离基体之后,热残余应力绝大部分被释放,膜内最终的残余应力可认为是本征应力。更多还原

【Abstract】 An FEA model was developed by the software ANSYS to simulate the residual stress in the free-standing thick diamond wafer before and after the wafer’s peeling-off from substrate.To get rid of the usual assumption that temperature field in diamond wafer of substrate is uniform or linear so as to make the simulation results closer to the actual conditions under which the diamond wafer can be fabricared,the plasma jet from a plasma torch controlled by DC electromagnetic field was introduced in simulation.The following conclusions were thus drawn:(1) Before peeling-off from substrate,the residual thermal stresses in wafer is in spatial state and the first principal stress becomes tensile in most area of a wafer except the central part,which may lead the wafer to crack.The tremendous shear stress at the interface between wafer and substrate is the main cause of the wafer’s peeling off from substrate.(2) After peeliug-off from substrate,most of residual thermal stress in wafer is released,then the small part of residual stress left in wafer may be considered as intrinsic stress.更多还原