费广涛
,
朱震刚
材料研究学报
本文研究了多晶99.999wt-%Al 在拉压疲劳早期阶段中应力、内耗、超声衰减随循环圈数的变化关系,以及它们与试样内部位错组态的联系。实验结果表明,当超声衰减达到最大值时,对应的位错组态为缠结带与单根位错并存,当应力达到最大值时,对应的位错组态为胞状结构。
关键词:
疲劳
,
stress
,
dislocation configuration
,
internal friction
,
ultrasonic attenuation
武明
,
褚武扬
,
李金许
,
姜波
,
陈刚
,
崔银会
金属学报
车轮钢在恒应力下充氢表面出现氢鼓泡的临界电流和无应力试样相同, 恒应力下临界可扩散氢浓度Cσ*落在无应力试样的分散带内, t检验表明应力对C0*没有影响. 恒应力下发生氢致滞后断裂的门槛电流密度和门槛可扩散氢浓度分别为ith=3 mA/cm2和Cth=0.52×10-6, 远小于出现氢鼓泡的相应值ic=5 mA/cm2和C0*=1.18×10-6. 无应力时, 氢鼓泡并不择优沿夹杂产生; 但在恒应力下, 氢鼓泡择优沿长条状夹杂形核, 其临界可扩散氢浓度从1.18×10-6降为0.56×10-6.
关键词:
氢鼓泡
,
stress
,
inclusion
,
wheel steel
,
flaking
王毅
,
褚武扬
,
宿彦京
,
高克玮
,
乔利杰
金属学报
用单边缺口拉伸试样研究了外加应力强度因子对PZT5铁电陶瓷电致瞬时断裂以及在硅油中电致滞后断裂的影响. 结果表明, 在硅油中发生瞬时断裂的临界电场强度随外加应力强度因子的升高而线性下降. 外加正、负恒电场在硅油中能发生滞后断裂, 外加K则促进电致滞后断裂. 电致滞后断裂的门槛电场随K升高而线性下降, 且和电场符号无关.外加应力促进恒电场下的滞后断裂表明, 应力、电场和环境对铁电陶瓷的断裂存在耦合作用.
关键词:
PZT铁电陶瓷
,
stress
Cheng LÜ
材料科学技术（英文）
Thermal, mechanical and microstructural phenomena are involved in the process of steel quenching. Based on the coupled metallo-thermo-mechanics theory, a calculation model has been developed in this study to simulate the quenching process of a gas turbine compressor disk by finite element method. The thermal physical and mechanical properties were treated as a functions of temperature. Moreover, a series of subroutines were developed on the MARC software platform. Consequently, simulated results on temperature, internal stress and distortion during the quenching were illustrated. With the aid of the simulated results, an optimum quenching scheme was proposed. The quenching process simulated in this study appears to be a promising tool in design of heat-treatment processing parameters for gas turbine compressor disks.
关键词:
Quenching stress
,
stress
,
Distortion
,
Finite
,
eleme
André Anders
中国表面工程
doi:10.11933/j.issn.1007-9289.2016.01.001
文中提出一种扩展的薄膜微观结构的区域相图,可以用其来表征过滤阴极弧以及高功率脉冲磁控溅射镀膜过程中含有大量离子流的动态沉积过程.其坐标轴包括广义同系温度,标量化动能以及可以表征离子刻蚀作用的净膜厚.需要强调的是,由于影响薄膜生长的实际参数要远超相图中有限的坐标轴数,因此该结构区域相图展示的生长条件与薄膜结构之间的关系是近似和简化过的.
关键词:
结构区域相图
,
薄膜制备
,
等离子体辅助
,
离子刻蚀
,
应力
,
形貌
,
同系温度
,
位能与动能
