Title of project: A study on the evaluations of fatigue strength and materials integrity of hard surface coatings

项目名称：硬表面涂层疲劳强度和材料完整性评价研究

基本信息

批准号：
09650093
负责人：
OGAWA Takeshi
金额：
$ 2.24万
依托单位：
Aoyama Gakuin University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1999
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09650093/
关键词：
Surface coating Fatigue strength Materials integrity Surface treatment Spraying

项目摘要

In the present study, fatigue strength and materials integrity of hard surface coatings have been evaluated. The coating material selected is a cermet (WC-12%Co) coating sprayed by high velocity oxygen fuel (HVOF) treatment. First rotating bending fatigue tests have been conducted at room temperature in laboratory air using specimens of medium carbon steel (S45C), low alloy steel (SCM435) and titanium alloy (Ti-6Al-4V) with the cermat sprayed coating and S45C with WFS sprayed coating of a 13Cr steel (SUS420J2). Plane bending fatigue tests were also conducted at stress ratios of 0, -0.5 and -1, The fatigue strength and fracture mechanisms were studied. Second, rolling contact fatigue of the WC-12%Co coated material was investigated on ring type plate specimen.Detailed observations of crack initiation and growth were performed and the results were compared with those obtained through stress distribution analysis performed by finite element method (FEM) and the crack initiation site was discussed, Third, inverse analysis of the velocity dispersion of laser excited surface acoustic wave (SAW) was used to estimate the elastic properties of three types of sprayed coatings, NiCrAlY, CrNiMoSiB and the WC-cermet. The obtained results were compared with those obtained by the mechanical methods of 3- or 4-point bending tests for the free standing specimen and/or sprayed specimen.Forth, with the aim of studying the effect of residual stress of the WC-cermet sprayed coating on fracture resistance, we evaluated the residual stresses of three coatings deposited by different spray conditions. AE monitoring and source characterization are utilized to study crack initiation and dynamics under quasi-static four-point bending condition.

在本研究中，已经评估了硬表面涂层的疲劳强度和材料完整性。选择的涂料是通过高速氧燃料（HVOF）处理喷涂的CERMET（WC-12％CO）涂层。使用中碳钢（S45C），低合金钢（SCM435）和钛合金（TI-6AL-4V）的中等碳钢（S45C）标本（s45c）标本在室温下进行了首次旋转弯曲疲劳测试13CR钢的涂层（SUS420J2）。还以0，-0.5和-1的应力比进行了平面弯曲疲劳测试，研究了疲劳强度和断裂机制。其次，在环型板样品上研究了WC-12％涂层材料的滚动接触疲劳。进行了裂纹起始和生长的测定观察结果，并将结果与通过有限元方法进行的应力分布分析（FEM）（FEM）进行了比较。）并讨论了裂纹启动位点，第三，对激光表面声波（SAW）的速度分散（SAW）的第三个反比分析来估计三种类型的喷涂涂层的弹性性能，即Nicraly，Crnimosib和WC-Cermet。将获得的结果与通过3分或4分弯曲测试的机械方法进行的自由样品和/或喷雾样品进行比较。涂层在断裂性上，我们评估了由不同喷雾条件沉积的三种涂层的残余应力。 AE监测和源表征可用于研究准静态四点弯曲条件下的裂纹启动和动力学。