炭素繊維／アルミニウム合金複合材料の引張強さおよび圧縮強さに及ぼす界面強さの影響

Abstract

The effect of the interfacial shear strength between the carbon fibers and the matrix of carbon fiber reinforced aluminium alloys (CFRM:two PAN based high modulus and a PAN based high strength CFs, Vf=70%) on the bending strength and the compressive strength has been studied. As the interfacial shear strength increases from a lower level of 5 MPa to a higher level of 25 MPa, the tensile strength of the CFRMs contains high modulus CFs decreases rapidly from a high level of 1, 300 MPa to a low level of 500 MPa. However, as the interfacial shear strengths is varied in this region, the compressive strength of the same CFRM increases sharply from a level of 400 MPa to a level of 1, 600 MPa. The compressive strengths of the CFRMs show a high, constant level of 1, 600 MPa in the range of interfacial shear strengths over 40 MPa. CFRMs with low interfacial shear strengths show fracture at the interface and compressive collapse in compression tests. As the interfacial shear strength of the CFRMs increases, fracture at the interface is reduced, and the probability of shear fracture increases. These changes increase the compressive strengths of the CFRMs. When the level of interfacial shear strength is over 40 MPa and the compressive strengths of the CFRMs exhibit an almost constant level of 1, 600 MPa, in this case the compressive specimens show complete shear fracture mode. The interfacial shear strength is considered to depend on the content of Al4C3 accumulated at the interface in the CFRMs.