Mechanical and fracture properties of an AZ91 Magnesium alloy reinforced by Si and SiC particles

作者：Trojanova Z^*; Gartnerova V; Jaeger A; Namesny A; Chalupova M; Palcek P; Lukac P

来源：Composites Science and Technology, 2009, 69(13): 2256-2264.

DOI：10.1016/j.compscitech.2009.06.016

• Metal matrix composites
• Plastic deformation
• Stress relaxation
• Scanning electron microscopy
• Casting
• Magnesium alloy
• Composite
• Mechanical properties
• Thermally activated process
• Fractography

A commercial AZ91 magnesium alloy (nominal composition Mg-9%Al; 1%Zn; 0.3%Mn, balance Mg in weight percent) reinforced with SiC particles and modified by the addition of Si has been used in this study. Formation of an "in situ" composite (Mg-Mg(2)Si) results in strong bonding between Mg(2)Si and the matrix interface. Samples were deformed in compression in the temperature interval from room temperature up to 300 degrees C. Stress relaxation tests were performed with the aim to reveal the thermally activated processes. Reinforcing effect of SiC and Mg(2)Si particles decreases with increasing temperature. The estimated values of the activation volume as well as the activation enthalpy indicate that the main thermally activated process is connected with a rapid decrease of the internal stress. Fracture properties were studied in impact tests at various temperatures. A ductility enhancement was found at 200 degrees C and temperatures above 200 degrees C.

• 出版日期2009-10