Effect of heat treatment on structure and mechanical properties of basalt fibers and its application for fabrication Cu based composite

Abstract

This paper firstly presents an experimental investigation of the effects of heat treatment temperatures and atmosphere on the tensile strength and structure of basalt fibers. The results show that the basalt fibers after heat treatment in air (200–600 °C) have the characteristics of amorphous state due to the oxidation of Fe ^2+ into Fe ^3+ . On the contrary, the vacuum heat treatment induces the crystallization of basalt fibers. The reason is that the Fe ^2+ cations can act as network modifiers and the Fe ^3+ can participate in and enhance glass network. Furthermore, the single fiber strength of basalt fiber decreases with the increase of heat treatment temperature. However, the single fiber strength of basalt fibers after vacuum heat treatment is about 3 times that of basalt fibers after air heat treatment. On this foundation, basalt fibers were used for fabrication of copper matrix composites by spark plasma sintering (SPS) and hot press sintering (HPS) for the first time. The results exhibit that the strength of basalt fibers reinforced copper matrix composites prepared by SPS is 276 MPa, which are higher than that by HPS (192 MPa) due to fast heating rate and short holding time.

Keywords

• basalt fibers
• heat treatment
• tensile strength
• copper matrix composites