β-SiC nanoparticle reinforced A1 matrix （nano-SiCp/A1） composite was prepared by a multi- step powder metallurgy strategy including presureless sintering, hot compacting process and hot extrusion. The microstructur...β-SiC nanoparticle reinforced A1 matrix （nano-SiCp/A1） composite was prepared by a multi- step powder metallurgy strategy including presureless sintering, hot compacting process and hot extrusion. The microstructures of the as-prepared composites were observed by scanning electronic microscopy （SEM）, and the mechanical properties were characterized by tensile strength measurement and Brinell hardness test. The experimental results revealed that the tensile strength of the composite with the addition of 5wt%/3-SIC nanoprtieles could be increased to 215 MPa, increasing by 110% compared with pure A1 matrix. Comparative experiments reflected that theβ-SIC nanoprticles showed significant reinforcement effect than traditional a-SiC micro-sized particles. The preparation process and sintering procedure were investigated to develop a cost effective preparation strategy to fabricate nano-SiCp/A1 composite.展开更多
采用不同Al含量的聚铝碳硅烷（PACS）为先驱体,通过不同的PACS纤维不熔化方法调节O引入量,制备了具有不同Al和O含量的连续Si Al CO纤维。研究了Si Al CO纤维经高温处理转变为Si（Al）C纤维过程中,Al、O含量对Si CxOy相分解、β-Si C结...采用不同Al含量的聚铝碳硅烷（PACS）为先驱体,通过不同的PACS纤维不熔化方法调节O引入量,制备了具有不同Al和O含量的连续Si Al CO纤维。研究了Si Al CO纤维经高温处理转变为Si（Al）C纤维过程中,Al、O含量对Si CxOy相分解、β-Si C结晶生长和微观形貌的影响。结果表明：纤维中Si CxOy相的分解温度区间为1300～1700℃,与Al、O含量基本无关;提高Al含量可减少纤维在高温下表面形成粗大Si C结晶颗粒和相互连通的气孔,并且对1700℃以上β-Si C结晶生长的抑制作用增强,有利于烧结致密化;利用纤维中O元素,以放出CO或CO2方式脱除富余C,但O含量过高导致气体逸出时产生较大孔洞,不利于烧结致密化。当Al和O含量分别约为0.6wt%和9wt%时,Si Al CO纤维经高温处理后能得到具有较大β-Si C晶粒尺寸的致密化Si（Al）C纤维。展开更多
基金The project was supported by the National Natural Science Foundation of China(21173251,21203233)Innovation Fund of Institute of Coal Chemistry,Chinese Academy of Sciences(Y1SC6R1991)State Key Laboratory of Coal Conversion,China(2013BWZ006)~~
基金Funded by the Research Collaborative Innovation Project of Jiangsu Province,China(BY2009129)the Science and Technology Project of Suzhou,China(SYG0905)
文摘β-SiC nanoparticle reinforced A1 matrix （nano-SiCp/A1） composite was prepared by a multi- step powder metallurgy strategy including presureless sintering, hot compacting process and hot extrusion. The microstructures of the as-prepared composites were observed by scanning electronic microscopy （SEM）, and the mechanical properties were characterized by tensile strength measurement and Brinell hardness test. The experimental results revealed that the tensile strength of the composite with the addition of 5wt%/3-SIC nanoprtieles could be increased to 215 MPa, increasing by 110% compared with pure A1 matrix. Comparative experiments reflected that theβ-SIC nanoprticles showed significant reinforcement effect than traditional a-SiC micro-sized particles. The preparation process and sintering procedure were investigated to develop a cost effective preparation strategy to fabricate nano-SiCp/A1 composite.
文摘采用不同Al含量的聚铝碳硅烷（PACS）为先驱体,通过不同的PACS纤维不熔化方法调节O引入量,制备了具有不同Al和O含量的连续Si Al CO纤维。研究了Si Al CO纤维经高温处理转变为Si（Al）C纤维过程中,Al、O含量对Si CxOy相分解、β-Si C结晶生长和微观形貌的影响。结果表明：纤维中Si CxOy相的分解温度区间为1300～1700℃,与Al、O含量基本无关;提高Al含量可减少纤维在高温下表面形成粗大Si C结晶颗粒和相互连通的气孔,并且对1700℃以上β-Si C结晶生长的抑制作用增强,有利于烧结致密化;利用纤维中O元素,以放出CO或CO2方式脱除富余C,但O含量过高导致气体逸出时产生较大孔洞,不利于烧结致密化。当Al和O含量分别约为0.6wt%和9wt%时,Si Al CO纤维经高温处理后能得到具有较大β-Si C晶粒尺寸的致密化Si（Al）C纤维。
