【作者】 王尧杰；

【导师】 赵军；

【作者基本信息】 山东大学 ， 机械制造及其自动化， 2008， 硕士

【摘要】 本论文以纳米复合陶瓷刀具材料的强韧性和抗热震性为研究内容,对以高强韧和高抗热震性为目标研究开发纳米复合陶瓷刀具材料具有重要的理论价值和实际意义。建立了纳米颗粒尺度与屈服强度的关系及临界晶粒尺寸的表达式;导出纳米复合陶瓷材料强度与残余热应力的关系及最佳晶粒与裂纹之比的表达式;推出纳米复合陶瓷材料桥联增韧机制的贡献;导出残余应力的增韧贡献及基于残余热应力增韧的纳米颗粒的最佳含量计算式;提出寻求统一抗热震评价参量作为抗热震理论体系的研究目标;通过临界温差解析,建立了纳米复合陶瓷刀具材料的抗热震性与断裂韧性的关系;建立了纳米复合陶瓷材料抗热震性激光热冲击仿真有限元模型;通过对非稳态温度场和热应力场激光热冲击仿真,得出了温度场与应力场之间具有协调同步的关系;利用软件,得出最大拉应力与热冲击时间的关系曲线以及最大拉应力与激光加热半径之间关系曲线等,并提出热流密度作为新的抗热震评价参量。更多还原

【Abstract】 Toughening-strengthening mechanisms and thermal shock resistance of nanocomposite ceramic tool materials were investigated as the main content of this thesis, which are of great importance for the design and development of nanocompsite ceramic tool materials with high toughening and strengthening as well as high thermal shock resistance.The theoretical model for studying the micro residual thermal stresses in nanocomposite ceramic tool material was established, by which the values and the distribution of residual thermal stresses induced by the nano inclusions were obtained. The effect of plasticity deformation on residual thermal stress was investigated. The residual thermal stresses in the intra and the inter granular of nanocompsite ceramic tool materials were analyzed .The toughening and strengthening mechanisms of nanocompsite ceramic tool materials were thoroughly researched. The contributions of several toughening and strengthening mechanisms were analyzed. The optimal content and critical size formulas of nano granule were educed. The relation between nanocompsite ceramic strength and residual thermal stresses was established. The thesis had finished the qualitative analyse of nanocompsite ceramic tool thermal shock resistance, by Al₂O₃-based nanocompsite ceramic tool thermal thock simulation test.更多还原