Application of High-Pressure Torsion to Al-Si Alloys with and without Scandium Additions
Al-2 wt. % Si alloys with and without 0.25 wt. % scandium additions were processed by highpressure torsion up to five turns at room temperature under a pressure of 6.0 GPa. Microstructural examination of the as-cast Al-2Si-0.25Sc alloy revealed the presence of Al3SC precipitates which refined the Al grain structure, whereas no major changes were observed in the morphology of the Si particles. Processing by HPT of both experimental alloys revealed submicrometer grains with uniformly distributed Si particles. The mechanical properties were obtained using hardness measurements and the ball-indentation technique. The results show the hardness increased in the first turn of HPT and further increased with increasing numbers of turns. In addition, the hardness values were lower at the centers and continuously increased towards the edges of the disks. The difference in hardness values between the centre and the edge decreased with increasing turns, thereby suggesting an increasing homogeneity with increasing processing. The scandium addition and HPT processing of the Al-2Si alloy strongly influences the grain refinement and mechanical properties. The grain size reduction in the Al-2Si alloy was similar to Al whereas the presence of Sc in Al-2Si during HPT processing was responsible for large precipitation networks and a submicrometer grain formation.
K.Venkateswarlu V.Rajinikanth Mani Kuntal Sen Saleh N.Alhajeri Terence G.Langdon
Materials Science Division,National Aerospace Laboratories (CSIR),Bangalore-560017,India National Metallurgical Laboratory (CSIR),Jamshedpur -831007,India Department of Manufacturing Engineering,College of Technological Studies,PAAET,Shuwaikh 70654,Kuwait Materials Research Group,School of Engineering Sciences,University of Southampton,Southampton SO17 1
国际会议
5th International Conference on Nanomaterials by Severe Plastic Deformation(第五届剧烈塑性变形纳米材料国际会议)
南京
英文
743-748
2011-03-01（万方平台首次上网日期，不代表论文的发表时间）