Authors: Woldetinsay Gutu Jiru; Mamilla Ravi Sankar; Uday Shanker Dixit; Hengcheng Liao
Addresses: Department of Mechanical Engineering, Indian Institute of Technology Guwahati, Guwahati, 781 039, India ' Department of Mechanical Engineering, Indian Institute of Technology Guwahati, Guwahati, 781 039, India ' Department of Mechanical Engineering, Indian Institute of Technology Guwahati, Guwahati, 781 039, India ' School of Materials Science and Engineering, Northeastern University, Shenyang, 110819, China
Abstract: This work investigated mechanical and metallurgical properties of Al-12Si-4Cu-1.2Mn high temperature alloy after laser surface melting using CO2 laser. The effect of laser specific energy on the quality of remelted surface was studied. Two kinds of substrate materials were compared - solutionised heat treated at 510°C and as-cast. The dendrite microstructure and refined grains with reduced average grain size improved the mechanical properties of laser surface remelted alloy. The micro-hardness of the alloy increased by 2.5 times for heat treated and 2.6 times for as-cast samples. The ultimate tensile strength increased by 70% and 23% for as-cast and heat treated alloys, respectively. Scratch resistance improved and coefficient of friction reduced. In general, low laser specific energy provided better results. Overall good mechanical properties were obtained when as-cast samples were remelted by CO2 laser at 45-50 J/mm2 laser specific energy.
Keywords: mechanical property; dendrite structure; laser surface melting; LSM; aluminium alloy; ultimate tensile strength; UTS; microhardness; CO2 laser; scratch test; laser specific energy; microstructure; solutionisation.
International Journal of Mechatronics and Manufacturing Systems, 2018 Vol.11 No.2/3, pp.230 - 249
Received: 16 Sep 2017
Accepted: 05 Feb 2018
Published online: 19 Jun 2018 *