Production of LM28 Tubes by Mechanical Alloying and Using Friction Stir Extrusion

Abstract

Friction Stir Extrusion (FSE), the focus of this research, is a process that has tremendous potential for shaping and improving the mechanical properties of the final product as well as the mechanical alloying. In this study, a cylindrical sample of LM13 aluminum, to which silicon powder is added, is extruded by the penetration of a tool and takes the shape of a tube. The microstructure of the aluminum tube produced is studied using a light microscope. Various tests, including compression and wear tests, are performed to evaluate the wear and mechanical properties of the tubes produced. Additionally, the process is simulated using the finite element method (FEM), and the strain and temperature distributions in the tubes are examined to understand the impact of tool advancing speed better. The strain and temperature are highest on the inner surface, where the tubes meet the tool. Moreover, as the advancing speed increases from 25 to 40 mm/min, the maximum temperature in the tubes increases from 350 to 400 °C. The surface quality of the samples is directly related to the advancing speed, so the surface quality improves as the advancing speed increases. The results obtained from the compression and wear tests show that the compression strength has increased by about 17%, and the wear resistance has improved by about 20%.

Keywords

• friction stir extrusion
• mechanical alloying
• aluminum/silicon alloy
• compression test
• wear-resistant fine-grained tubes