摘要
采用单轴模压法,以Cu-Fe基元素混合粉末为原料,在不同冷压压力下制备Cu-Fe基金刚石复合材料超薄切锯胎体压坯;利用修正Heckel模型建立压制压力与压坯相对密度的关系,用显微硬度仪、OM、SEM和阿基米德原理表征粉末松装密度、冷压坯的显微硬度、冷压坯的组织和密度。结果表明:修正Heckel模型的精确度高,模型在149、187和224 MPa压力下相对密度的计算值与实验值相吻合;但随压制压力的增大,压坯中粉末的变形越来越不均匀,粉末颗粒间摩擦力不断发生变化,并且模型低估了高压力下粉末的加工硬化,使168和205 MPa压力下的计算值高于实验值;由于压坯的高径比很小,粉末体的横向变形受到抑制,使得压坯组织呈轴、径向相异的特征,模型拟合的泊松比值小于文献报道。
A compact of Cu-based diamond composite ultra thin sawing matrixes was prepared by cold uniaxial compaction technology at different cold pressure using Cu-Fe based element mixed powders as raw material.The microstructure,density and microhardness of the compact were investigated by OM,SEM,Archimedes principle and microhardness tester.The results show that Heckel model has high precision and the relative density calculated by using the model is fitting with that of experimental value at the pressure of 149,187 and 224 MPa,however,increasing pressure,the calculated values at 168 MPa and 205 MPa are higher than that of experimental ones because of overestimated the work hardening,non uniform deformation and changing inter-powder force of the powder;in addition,due to the much smaller aspect ratio of the compact,transverse strain is restrained which causes the axial and radial microstructure anisotropy at different pressure and the fitting Poisson’s ratio is lower than that of literature report.
出处
《粉末冶金材料科学与工程》
EI
北大核心
2013年第3期326-332,共7页
Materials Science and Engineering of Powder Metallurgy
基金
国家自然科学基金资助项目(51165021)
