The aging behavior of Ni-coated carbon fibers and ZrC particles reinforced 2024Al matrix composites

Abstract

In this paper, the aging behavior of Cf(Ni)-ZrC/2024Al composites with a quasi-network structure was studied carefully. The microstructure observation exhibits that the ZrC particles, carbon fibers, and Al matrix form a good interface bonding. The interfacial phase between the carbon fiber and Al matrix exhibits good thermostability during solution and aging treatment. With the addition of carbon fibers and ZrC particles, the composites only take 8 h to reach peak-aged condition while in monolithic 2024Al alloy, it needs 12 h. The peak-aged hardness of the composites is 136.4 HV, having 15.2% increments than 2024Al (118.4 HV). The yield, tensile strength, and strain of the peak-aged composites are 350.5 MPa, 536.4 MPa, and 14.8% respectively, which are improved by 56.5%, 45.8%, and 52.6% compared with 2024Al. The yield and tensile strength of composites are increased with time going by until they reach a peak aging state, agreeing well with that of hardness. The TEM observations of precipitated phases demonstrate the size and number of Al 2 Cu and Al 2 CuMg present a similar variation tendency. The improved tensile property of the composites is mainly due to pulled-out carbon fibers, quasi-network structure, outstanding interface bond, and precipitate strengthening. • The Cf(Ni)-ZrC/2024Al composites only take 8 h to reach to peak-aged condition, while the 2024Al needs 12 h. • The yield, tensile strength and strain of the composites are significantly improved compared with the 2024Al. • The improved strength is due to pulled-out carbon fiber, quasi-network structure, good interface bond and fine precipitate.