Prestress Engineering and Surface Nanocrystallization of Structural Materials:Process-Properties and Applications
- 作者：吕坚
- 会议时间：2008-11-17
- 作者单位：香港理工大学机械系
- 母体文献：2008中国(宁波)新材料与产业化国际论坛论文集
- 会议名称：2008中国(宁波)新材料与产业化国际论坛
- 会议地点：宁波
- 主办单位：中国机械工程学会
- 语种：chi
摘要
The prestress and nanocrystallization are categories of material processing for enhancing the mechanical performances of the structural materials.The first part deals with the prestress engineering.It is a global approach for taking into account the processing induced residual stress in mechanical design and the structure health monitoring.This involves research in three fields:process development,residual stress determination and numerical tools.The destructive (incremental hole drilling method) and non-destructive (x-ray,neutrons diffraction,ultrasonic) methods have been combined in order to evaluate precisely the residual stresses distribution.Some new results concerning the new development of the optic methods for the in depth residual stress distribution measurement will be shown.A special attention is paid to residual stress induced in advanced composite materials such metal and polymer matrix composites.Then the residual stresses obtained by the thermal spraying coating technology with different coating systems (Zirconia,Cr2O3,WC-Co,NiCrAIY) manufactured by different processes (HVOF,APS,VPS,ATCPS) will be shown.The effects of the residual stress on the toughness and strength of the coatings are also discussed.The effect of residual stresses on fatigue behavior will be also mentioned.A model based on the finite element method for the prediction of the relaxation of the residual stresses will be presented.It's now possible to study the 3D relaxation of residual stress by the finite element method.Then,the prediction of the fatigue life taking the residual stresses into account using the finite element method and the results of fatigue life graph obtained by 3D software will be shown.