颗粒增强复相陶瓷残余应力和增韧机制分析

对颗粒增强复相陶瓷在增强颗粒密排分布条件下材料内残余应力的大小和分布进行了理论分析，探讨了αｐ〉αｍ和αｐ〈αｍ情况下的强化增韧机制以及在这两种情况下所存在的增韧机制的差别。研究结果表明，残余应力不仅与基体和颗粒的物理参量有关，而且还与所在点位置和增强颗粒体积含量有关。颗粒增强复相陶瓷在αｐ〉αｍ和αｐ〈αｍ情况下，都可能达到强化增韧的效果。在αｐ〈αｍ情况下，主要增韧机制是裂纹偏转和残余应力场强     

弥散SiC颗粒增韧Al2O3基陶瓷的增韧机制分析

通过对SiC-Al2O3陶瓷材料内部残余应力的分析,根据Griffith微裂纹理论,从多个角度分析了弥散SiC颗粒对Al2O3材料的增韧机制.     

弥散SiC颗粒增韧Al_2O_3基陶瓷的增韧机制分析

通过对SiC Al2 O3 陶瓷材料内部残余应力的分析 ,根据Griffith微裂纹理论 ,从多个角度分析了弥散SiC颗粒对Al2 O3 材料的增韧机制     

弥散相增韧及相变增韧陶瓷综述

弥散相增韧及相变增韧陶瓷复合材料是改善陶瓷韧性和强度的有效措施,近年来极受重视,发展迅速.本文简要介绍制备复合材料时应考虑的主要问题、制备技术和达到的强化增韧效果,以及今后进一步研究的课题.     

颗粒增韧陶瓷的增韧机理

综合评述并分析了第二相颗粒增韧脆性陶瓷材料的几种主要增韧机理及各种论点和这些增韧机理的适用范围，并主要从第二相颗粒的粒径着手进行了分类讨论。     

氧化物陶瓷增韧技术的研究

本文以工业纯ＺｒＯ２和工业纯Ａｌ２Ｏ３的原料,采用多元稳定剂的复合添加技术和弥散颗粒预合成工艺制备ＺＴＡ（氧化锆增韧氧化铝）复相陶瓷。通过对材料的制备、烧结性能和力学性能的研究,找出了与ＺＴＡ材料最佳抗弯强度和断裂韧性相对应的最佳工艺参数,并讨论了稳定剂含量以及弥散颗粒含量对ＺＴＡ材料力学性能的影响。     

反应合成AlN／TiB2复相陶瓷及残余应力分析

采用ＸＲＤ法研究了ＴｉＨ２，Ａｌ及ＢＮ反应过程中物相的生成机理，发现在不同温度下存在ＴｉＡｌ３，ＴｉＮ，－α－Ａｌ２Ｏ１等过渡相，但最终只有ＡｌＮ和ＴｉＢ２两相存在，并结合热力学分析，认为合成ＡｌＮ／ＴｉＢ２的反应温度应在１７００℃以上。通过反应热压法制备出了ＡｌＮ／ＴｉＢ２复相陶瓷，材料的三点弯曲强度为５３９ＭＰ，ＫＩＣ为５．０５ＭＰａ．ｍ＾１／２。     

金属颗粒增韧氧化铝陶瓷研究现状

概述了金属颗粒增韧氧化铝陶瓷的研究进展,对氧化铝/金属复合材料的研究现状、增韧机理及制备方法进行了介绍,并对氧化铝/金属复合材料的主要发展方向进行了分析预测。     

原位生成TiB2颗粒增韧SiC基复相陶瓷研究

提出一种新的方法制备ＳｉＣ－ＴｉＢ２颗粒复相陶瓷。通过Ｔｉ，Ｓｉ与Ｂ４Ｃ之间的化学反应在ＳｉＣ基体中原位生成ＴｉＢ２颗粒，获得的ＴｉＢ２颗粒一般在５μｍ以下，但发现有ＴｉＢ２颗粒团聚现象。其中ＳｉＣ－ＴｉＢ２３０％（ｖｏｌ）复相陶瓷的断裂韧性和三点弯曲强度分别比ＳｉＣ基体提高约１倍，达到４．５ＭＰａ·ｍ＾１／２和４００ＭＰａ。认为ＴｉＢ２颗粒与ＳｉＣ基体之间热膨胀系数不同导致的残余应力场引起的裂纹     

Al2O3-TiC复相陶瓷表面残余应力的研究

本论文应用4种不同的工艺对Al2O3-TiC复相陶瓷进行表面处理,以改变其表面残余应力分布状态。利用扫捕电子显微镜(SEM)观察试样的表面形貌;采用非破坏性的X射线衍射法,对不同工艺条件下的残余应力进行测试研究。结果表明：在本研究条件下,经平面磨处理后．试样表面处于拉应力状态;经工具磨处理后,试样表面处于压应力状态;经抛光处理后,残余应力值均有所减小、这对于提高陶瓷材料的强度和耐磨性具有重要的意义。     

Al2O3陶瓷表面加工残余应力的研究

讨论了四种不同的工艺对Al2O3-TiC复相陶瓷进行表面处理,以改变其表面残余应力分布状态。利用扫描电子显嫩镜(SEM)观察试样的表面形貌;采用非破坏性的X射线衍射sin^2ψ法,对不同工艺条件下的残余应力进行了测试研究。结果表明：在本研究条件下,经平面磨处理后．试样表面赴于拉应力状态;经工具磨处理后,试样表面处于压应力状态;经抛光处理后,残余应力值均有所减小。这对于提高陶瓷材料的强度和耐磨性具有重要的意义。     

Determination of Residual Stress in Coatings by a Membrane Deflection Technique

A membrane deflection technique has been developed to measure the isotropic residual stress in biaxially-constrained coatings. The technique has been demonstrated on various materials, including polyimide, latex rubber and photoresist coatings. Stress values obtained from membrane deflection compared well with results obtained from time-averaged vibrational holographic interferometry except for values obtained from samples where rigidity effects were found to be important. A criterion based on the thickness, rigidity, stress and sample radius is also discussed, establishing the applicability of the technique to samples of low rigidity.     

Determination of Residual Stress in Coatings by a Membrane Deflection Technique

A membrane deflection technique has been developed to measure the isotropic residual stress in biaxially-constrained coatings. The technique has been demonstrated on various materials, including polyimide, latex rubber and photoresist coatings. Stress values obtained from membrane deflection compared well with results obtained from time-averaged vibrational holographic interferometry except for values obtained from samples where rigidity effects were found to be important. A criterion based on the thickness, rigidity, stress and sample radius is also discussed, establishing the applicability of the technique to samples of low rigidity.     

Residual thermal stress analysis of SiC joint by polysiloxane silicon resin YR3187

Reaction-bonded silicon carbide was joined using a polysiloxane silicon resin YR3187. Residual thermal stress distribution in joint structure was calculated by finite element analysis method. Factors influencing the distribution of residual thermal stress, including joining temperature, thickness of join layer, and presence of crack in join layer, were studied. The simulated results were compared with actual joint strength. It is showed that in determining the joining temperature, the pyrolysis procedure of silicon resin should be taken into consideration; in addition, the reasonable thickness of the join layer and the reduction of cracks in join layer are important to obtain higher joint strength.     

激光强化电刷镀Ni镀层残余应力研究

利用Nd3+:YAG激光器和电刷镀设备制备了激光强化电刷镀Ni层,采用X-射线衍射法测定了镀层的轴向残余应力,分析了残余应力随镀层厚度变化的情况.结果表明,当镀层δ从10μm增加到200μm时,激光电刷镀Ni层轴向残余应力由压应力逐渐过渡为拉应力,最大值为197 MPa(激光功率300W、镀层δ为200μm),比普通电...     

注塑制品残余应力测定方法

残余应力对制品的形状、表面质量及使用性能有重要影响，本文针对注塑制品，介绍了4种残余应力的测定方法、测定原理及计算方法，其中包括双折射法、剥层法、钻孔法、应力松驰法。评述了各种测试方法的优缺点。     

Influence of Residual Stresses on the Wear Behavior of Alumina/Alumina–Zirconia Laminated Composites

Symmetric structures of laminated ceramic composites were produced by superimposing alternating layers of Al₂O₃ and Al₂O₃/ZrO₂ composite prepared by tape casting. The composites were designed to have an alumina surface layer on either side. This configuration caused residual compressive stresses to be induced on the surface due to the different thermal expansion coefficients of the various layers, leading to an increase in the apparent surface toughness. The amount of residual stress was determined using the indentation technique. The tribological behavior of these laminated structures was evaluated using the pin-on-disk method for different loads and sliding speeds. Comparison with the results obtained from stress-free alumina showed that, within the range of these experimental conditions, the improvement in surface toughness leads to a reduced friction coefficient and increased wear resistance of the composites. Possible wear mechanisms are proposed.