DAMPING BEHAVIOR OF IN-SITU Al - (GRAPHITE, A1_4C_3) COMPOSITES PRODUCED BY RECIPROCATING EXTRUSION

摘要

The effect of graphite particles on the damping behavior of 6061 Al-graphite composites was investigated with an aim to develop a high damping, stiffness and hardness material. The composites were processed by mixing 6061 alloy powder with graphite particles, hot pressed as a billet and consolidated by reciprocating extrusion for 10 times. The results show that the graphite particles were greatly refined and uniformly distributed in the matrix. The graphite in-situ reacted with the Al matrix to form fine dispersed A1_4C_3 particles both during reciprocating extrusion and subsequent solution treatment. A1_4C_3 phase could result in a pronounced dispersion strengthening effect. The damping capacity of the composite increased with increasing graphite content. The composite showed a peak in damping capacity during aging treatment. The 6061 Al - 20 % (graphite, A1_4C_3) composite solution-treated for 24 h and peak-aged displays an excellent combination of damping capacity, stiffness and hardness.