β-SiC nanowires(SiCNWs) were selectively grown in the interlaminar matrix with a volume fraction of0.65% by applying a pyrocarbon coating on carbon fibers, which realizes the proper reinforcement of C/C composites. T...β-SiC nanowires(SiCNWs) were selectively grown in the interlaminar matrix with a volume fraction of0.65% by applying a pyrocarbon coating on carbon fibers, which realizes the proper reinforcement of C/C composites. The thickness of the pyrocarbon is optimized to 0.5 μm based on the analysis of in-situ fiber strengths with the fracture mirror method. The pyrocarbon coating increased the in-situ fiber strength by^7% and prevent brittle fracture of the composites. Compared with C/C, the interlaminar shear and flexural strength of SiCNW-C/C(10.06 MPa and 162.44 MPa) increase by 158% and 57%. Incorporating SiCNWs changes the crystallite orientations and refines the crystallite size of pyrocarbon matrix. The functions of SiCNWs vary with their loading density. When SiCNWs are sufficient in the matrix, they help reinforcing and improving the critical failure stress of the matrix. When their density decreases to a certain degree, SiCNWs help changing the crystallite orientations of pyrocarbon and toughening the matrix.展开更多
The effects of voids(void content,void shape and size)on the interlaminar shear strength of[(±45)_(4)/(0,90)/(±45)_(2)]_(S) and [(±45)/0_(4)/(0,90)/0_(2)]_(S) composite laminates were investigated.Speci...The effects of voids(void content,void shape and size)on the interlaminar shear strength of[(±45)_(4)/(0,90)/(±45)_(2)]_(S) and [(±45)/0_(4)/(0,90)/0_(2)]_(S) composite laminates were investigated.Specimens with void contents in the range of 0.2%-8.0%for [(±45)_(4)/(0,90)/(±45)_(2)]_(S) and 0.2%-6.1%for[(±45)/0_(4)/(0,90)/0_(2)]_(S) were fabricated from carbon/epoxy fabric through varying autoclave pressures.The characteristics of the voids were studied by using optical image analysis to explain the interlaminar shear strength results.The influences of voids on the interlaminar shear strength of the two stacking sequences were compared in terms of the void content and size and shape of the void.The effect of voids on the initiation and propagation of interlaminar failure of both stacking sequence composites was found.展开更多
基金supported by the National Natural Science Foundation of China under Grant Nos. 51502242, 51432008, U1435202the Fundamental Research Funds for the Central Universities (3102016ZY009)
文摘β-SiC nanowires(SiCNWs) were selectively grown in the interlaminar matrix with a volume fraction of0.65% by applying a pyrocarbon coating on carbon fibers, which realizes the proper reinforcement of C/C composites. The thickness of the pyrocarbon is optimized to 0.5 μm based on the analysis of in-situ fiber strengths with the fracture mirror method. The pyrocarbon coating increased the in-situ fiber strength by^7% and prevent brittle fracture of the composites. Compared with C/C, the interlaminar shear and flexural strength of SiCNW-C/C(10.06 MPa and 162.44 MPa) increase by 158% and 57%. Incorporating SiCNWs changes the crystallite orientations and refines the crystallite size of pyrocarbon matrix. The functions of SiCNWs vary with their loading density. When SiCNWs are sufficient in the matrix, they help reinforcing and improving the critical failure stress of the matrix. When their density decreases to a certain degree, SiCNWs help changing the crystallite orientations of pyrocarbon and toughening the matrix.
基金Project supported by Harbin Aircraft Industry Co.,Ltd.,China。
文摘The effects of voids(void content,void shape and size)on the interlaminar shear strength of[(±45)_(4)/(0,90)/(±45)_(2)]_(S) and [(±45)/0_(4)/(0,90)/0_(2)]_(S) composite laminates were investigated.Specimens with void contents in the range of 0.2%-8.0%for [(±45)_(4)/(0,90)/(±45)_(2)]_(S) and 0.2%-6.1%for[(±45)/0_(4)/(0,90)/0_(2)]_(S) were fabricated from carbon/epoxy fabric through varying autoclave pressures.The characteristics of the voids were studied by using optical image analysis to explain the interlaminar shear strength results.The influences of voids on the interlaminar shear strength of the two stacking sequences were compared in terms of the void content and size and shape of the void.The effect of voids on the initiation and propagation of interlaminar failure of both stacking sequence composites was found.
