Fatigue Strength and Fracture Mechanisms in Intermetllic Compound Particlate-Reinforced

金属间化合物颗粒增强材料的疲劳强度和断裂机制

基本信息

批准号：
06650081
负责人：
KATAGIRI Kazumune
金额：
$ 1.22万
依托单位：
IWATE UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1994
资助国家：
日本
起止时间：
1994 至 1995
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-06650081/
关键词：
Fatigue Strength Fatigue Crack Propagation Variable Stressing Elevated Temperature Metal Matrix Composites Die Casting NiAl Particle Ni_3Al Particle アルミニウム合金体積分率空洞析出物

项目摘要

Through the evaluation on static mechanical properties and fatigue characteristics as well as the microscopiic observations, it has been revealed that the intermetalic compund, NiAl and Ni_3Al, particle-reinforced Al die cast are superior to the SiC reinforced one as is shown in the followings.1. The endurance limit increases by reinforcement at room temperature. While the endurance limit ofmatrix die cast and SiC particle reinforced one decrease with temperature rise, reinforcement is effective at 200ﾟC in the NiAl and up to 300ﾟC in Ni_3Al particle. The endurance limit and fatigue life-time increase with increase in the particle volume fraction in all temperature ranges examined. Although these characteristics basically corresponds to that of 0.2% proof stress, suppression of local slip by the intermetalic compound particles together with precipitates such as Al_3Ni significantly contribute the fatigue strength at low stress.2. Fatigue crack initiates at voids located near the surfac … More e which are introduced on casting in all die casts. Crack propagates through the matrix and along the particle-matrix interface, and the former is dominant at elevated temperatures. No cracking in Ni_3Al particle is found.3. Fatigue crack propagation resistance of 2.5 vol% NiAl particle reinforced die cast is higher at near threshold region than the matrix and SiC reinforced one. It decreases when the particle volumefraction increase beyond 2.5%. In the crack propagation rate range of Paris rule or beyond it, 2.5 vol% NiAl particle reinforced die cast has higher crack propagation resistance while SiC has such low resistance as that in the matrix : These characteristics dose not coinside with that of fracture toughness.4. NiAl particle reinforce die cast has excellent fatigue characteristics against the two stage (low-high and high low) varying stress fatigue. Acceleration of fatigue crack propagation under intermittent oversrtressing and its microscopic mechanism in the intermetalic compound particle reinforced die cast is open problem. Less

通过评估静态机械性能和疲劳特性以及微观观察结果，已经揭示了金属间的组合，NIAL和NI_3AL，颗粒增强的Al模具铸件优于SIC加强，如下所示。1。耐力极限通过在室温下加固而增加。虽然马trix模具的耐力极限和SIC颗粒加强了一个随温度升高的降低，但在NIAL粒子中，增强剂在NIAL中有效于200 c c，最高为300°C。在检查的所有温度范围内，随着颗粒体积分数的增加，耐力极限和疲劳寿命增加。尽管这些特征基本上与0.2％的证明应力相对应，但金属间化合物颗粒对局部滑动的抑制作用以及诸如Al_3ni之类的贵重物质显着促进了低应力下的疲劳强度。2。疲劳裂纹会启动位于表面附近的空隙中……更多的E在所有模具铸件中都引入了。裂纹通过基质和粒子矩阵界面传播，前者在升高温度下占主导地位。未发现Ni_3al粒子中的破裂3。在接近阈值区域，疲劳裂纹的传播耐药性在接近阈值区域高于基质和SIC增强。当粒子体积分数增加超过2.5％时，它会减少。在巴黎规则的裂纹传播速率范围内，2.5 vol％nial粒子增强铸件具有较高的裂纹耐药性，而SIC具有较低的电阻，就像矩阵中的抗抗性：这些特征剂量不是与裂缝韧性的剂量。4。 NIAL颗粒增强模具铸件具有出色的疲劳特性，该特性在两个阶段（低和高）变化的应力疲劳变化。间歇性过压力及其在金属间化合物颗粒增强模具铸件中的疲劳裂纹繁殖加速度是开放的问题。较少的