Effect of boron on aging strengthened phase and properties of Cu–Cr–Zr alloy

Abstract

The effect of trace B on the properties and microstructure of Cu–Cr–Zr alloy was investigated in this work. Aging precipitation phases in Cu matrix were analyzed by transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM). It was found that Cr is the main precipitation phase and its precipitation process is affected by B. Boron can increase the precipitation rate of the precipitation phase and promote the precipitation of the precipitation phase. After Cu–Cr–Zr alloy aged at 480 °C for 2 h, nanosized Cr particles were coherent with the Cu matrix and formed coherent G.P zones. In Cu–Cr–Zr alloy with 0.03wt% B addition, the aging precipitation process was accelerated, resulting in most of the aging precipitate being bcc Cr. Effect of trace B on hardness and electrical conductivity of Cu–Cr–Zr alloy was tested. It is indicated that B addition improves the hardness and electrical conductivity of the alloy and 0.03wt% B corresponds to the peak value of conductivity and hardness of Cu–Cr–Zr–B alloy.