姚旺
,
张宇民
,
韩杰才
,
查炎峰
,
周玉锋
,
韩媛媛
,
曲伟
无机材料学报
doi:10.3724/SP.J.1077.2009.00301
借助X射线衍射方法测量了反应烧结碳化硅(RBSiC)材料的磨削表面的残余应力状态，并根据断裂力学评价了磨削引入的裂纹尺寸，分析了RBSiC的弯曲强度受磨削引入裂纹和残余应力的影响.研究表明，由于磨削过程中与磨削方向有关的机械载荷占主导作用，使磨削后的表面残余应力具有方向依赖性.砂轮轴向进给从0.90μm/s增加到1.35μm/s，磨削表面的残余压应力数值降低，计算得到的磨削引入的裂纹尺寸增大，导致强度下降.
关键词:
碳化硅
,
grinding
,
residual stress
,
crack
,
strength
王迎军
,
宁成云
,
陈楷
,
赵子衷
,
李尚周
,
马利泰
,
冯景伟
,
黄瑞福
无机材料学报
本研究设计的生物活性梯度涂层材料，通过降低涂层与基体间的热膨胀系数差值，并对喷涂后的涂层材料进行适当热处理，有效地降低了涂层的残余应力，涂层结合强度可达38MPa左右．本实验采用X射线sin2Ψ法对涂层残余应力进行测试，探讨涂层残余应力与结合强度的相互影响关系．
关键词:
生物活性梯度涂层
,
plasma-spray
,
residual stress
,
bonding strength
李美栓
,
辛丽
,
马信清
,
彭晓
,
周龙江
,
李铁藩
腐蚀科学与防护技术
利用拉力法测量了Ti-5621S及含1wt%Nd的Ti-5621S合金800℃空气中形成的氧化膜的粘附力,用膜/合金界面能表征的氧化膜的粘附力不仅与断裂载荷有关、而且还与膜内的残余应力有关.简化分析后得出它们间存在关系Ti-5621S合金中添加Nd能增强氧化膜粘附力,两种合金氧化膜的粘附力随厚度增加而降低.
关键词:
氧化
,
oxide adherence
,
residual stress
,
Nd
,
Ti-5621S
鄢东洋史清宇吴爱萍JuergenSilvanus
金属学报
利用数值模拟技术分析搅拌头机械载荷在焊接过程中的作用, 通过对比只考虑热载荷, 考虑热载荷和搅拌头的下压力, 综合考虑热载荷、搅拌头下压力和工作扭矩三种条件下的应力、应变和变形, 结果发现, 搅拌头下压力使焊后残余应力值大幅下降; 搅拌头的工作扭矩是焊后残余应力、应变不对称分布的重要影响因素; 并且搅拌头机械载荷使得薄板焊后残余变形的模式发生了完全相反的变化, 由不考虑搅拌头载荷时的马鞍状变成了反马鞍状.
关键词:
搅拌摩擦焊
,
numerical simulation
,
residual stress
,
residual strain
,
residual distortion
J
,
H
,
Wang
,
H. Lu and H. Murakawa 1) Shanghai Jiao Tong University
,
Shanghai 200030.China 2) Osaka University
,
Japan
金属学报(英文版)
Local postweld heat treatment (PWHT)is usually performed when it is impractical to heat treat the whole vessel in a furnace, Many factors have an influence on PWHT procedures, such as size of the pipe,heated widths, insulation conditions, heating rates soak temperatures and hold times, material composition etc,. However up to now the influences these factors have on PWHT are not very clearly understood and different criteria for sizing the parameters can be found in different codes. This study provides a direct method to assess the effectiveness of local PWHT.An axisymmetrical model was used based on the thermal-visco-elastic-plastic Finite Element Method with the consideration of creep phenomena. By using this method both temperature and stress distributions can be simulated during whole local PWHT history. The computation results of temperature distributions and the strain histaries during local PWHT are compared with the experiments, and good agreements are obtained, Investigations show that the thermal stresses induced by local PWHT are much affected by creep behavior and the changes of Young's Modulus. The study of stress relief history shows that the stresses decrease quickly in the heating stage, then decrease slowly according to creep law in the hold stage and then studdenly increase when the cooling stage starts. The study shows the possibility that through a series of computations the effects of many factors can be assessed and the optimum parnmeters can be found. Compared with the heated widths based apon some applicable codes, it is found that a heated area of 2.5 on either side of the weld seems more reasonable.
关键词:
postweld heat treatment
,
null
,
null
,
null
韩玉君
,
叶福兴
,
陆冠雄
,
刘彻
,
郝杰
稀有金属材料与工程
用超音速氧燃料热喷涂在铁基合金上制备热障涂层粘结层,用大气等离子热喷涂技术制备陶瓷层.研究了高温氧化后其界面化合物和残余应力的演变.结果表明,随着高温氧化的进行,TGO和BC/基体界面均有氧化物生成,但生长形貌和趋势并不一致.TGO由Al2O3层与尖晶石层组成;BC/基体界面氧化物为单一Al2O3,且存在层状和块状两种形貌.合金的热化学动力学引起元素Co和Ni向基底扩散比较严重,Al元素扩散止于界面氧化物层,基本不向铸铁基底扩散,Fe元素会向粘结层方向扩散.TGO残余应力的演化分为0～15 h和15～100 h 2个阶段,且残余应力与TGO的凹凸生长形貌及其物相组成密切相关;而BC/基体界面单一氧化物的残余应力基本稳定,不受其生长形貌影响.
关键词:
超音速氧燃料热喷涂
,
热障涂层
,
高温氧化
,
尖晶石
,
残余应力
陈爱华
,
杨瑞霞
,
杨帆
,
刘志国
,
孙聂枫
人工晶体学报
运用原位磷注入合成法在高压单晶炉内合成富磷的InP熔体,并利用液封直拉法(LEC)生长出了3英寸富磷掺Fe的InP单晶.运用高分辨率X射线衍射技术、偏振差分透射谱测试技术、光致荧光谱技术对富磷掺Fe的InP晶片进行了结构、应力及发光特性测试.结果表明,晶格的应变导致了PL发光峰峰位的变化,晶格应变与残留应力测试结果相一致,说明材料生长过程中的热应力是导致样品晶格常数分布不均匀的主要因素.
关键词:
磷化铟
,
液封直拉法
,
晶格应变
,
残留应力
