Preparation of Carbon Fiber/Aluminium Composite and Its Mechanical Strength

Abstract

Three composites CF-Al, CF(Ni)A1 and CF(Cu)Al of carbon fiber/aluminium were prepared by the hot pressing techniques at temperatures of 500°C (P-method) and 670°C (M-method), and at a constant pressure of 200kg/cm2 (2.03×10⁷ Pa). Carbon fiber was co ated by Ni or Cu metals in order to have a good joining with the aluminium matrix. The maximum tensile strength of CF(Cu)A1 composite was abo u t three times as large as that of (Cu)Al metal composite. Although two hot pressing techniques of P- and M-methods were used, the former was superior to the latter because it gives the composi te with better joining characteristics between carbon fiber and metal matrix (plus a coating agent) and less solibility of metals into carbon fiber. EPMA study of CF(Cu)Al composite revealed that about 50-60% Al diffused to Cu and that Cu diffused only 5% to Al and slightly diffused to carbon fiber. On the other han d, in a case of CF(Ni)Al composite, 2-10% of Ni diffused to Al, but about 30% o f Al diffused to Ni. It was fou n d that the tensile strengths of the three composites studied were in agreement with those obtained by the use of Telelman's fracture toughness mechanism.