MICROSTRUCTURES AND MECHANICAL-PROPERTIES OF AL-LI SICP COMPOSITE PRODUCED BY EXTRUSION PROCESSING/

This paper describes the influence of extrusion parameters on the micr ostructures and the mechanical properties of SiC particles reinforced AI-Li composite. Al-Li/SiCp composite powders were mechanically milled at 500 rpm. The composite powders were consolidated at 573K by hot pr essing, and then extruded at 773K with different reduction ratios. The specimens extruded at the reduction ratio of 10 had difference of SiC p distribution between the core and the outer layer, while the differe nce was not almost observed for specimens extruded at over 20. The inc rease of reduction ratio improved the distribution of SiC particles an d gave recrystallization of Al-Li matrix, and the consequently tensile properties was enhanced. But higher reduction ratio such as 40:1 decr eased the mechanical properties. The reduction ratio of 20:1 was super ior in the mechanical properties of extruded Al-Li/10vol%SiCp composit e under all of conditions.