Laser surface alloying (LSA) of aluminium (AA 1200) with TiB2 for hardness improvement

Abstract

The present work deals with the development of Aluminium metal matrix composite (MMC) using TiB2 reinforcement. The aim is to improve the microhardness property of the substrate. The surface of the aluminium was sand blasted to improve its laser energy absorption and simultaneous deposition of the ceramic powder onto the surface of the substrate was carried out using a Rofin Nd: YAG laser with an Argon shield environment to prevention oxidation. The laser processing parameters were varied. The characterization of the alloyed surfaces MMC was carried out by Optical Microscopy (OPM), Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD). The microstructure of the alloyed layer shows that the ceramic powder was well dispersed within the Al-matrix. Good metallurgical bonds were evident. Microhardness measurements were carried out. The maximum depth attained was 1.17 mm. There was a microhardness increase from that of substrate which is 24±0.4 HV to that of the MMC layer 58.0±0.2 HV.The present work deals with the development of Aluminium metal matrix composite (MMC) using TiB2 reinforcement. The aim is to improve the microhardness property of the substrate. The surface of the aluminium was sand blasted to improve its laser energy absorption and simultaneous deposition of the ceramic powder onto the surface of the substrate was carried out using a Rofin Nd: YAG laser with an Argon shield environment to prevention oxidation. The laser processing parameters were varied. The characterization of the alloyed surfaces MMC was carried out by Optical Microscopy (OPM), Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD). The microstructure of the alloyed layer shows that the ceramic powder was well dispersed within the Al-matrix. Good metallurgical bonds were evident. Microhardness measurements were carried out. The maximum depth attained was 1.17 mm. There was a microhardness increase from that of substrate which is 24±0.4 HV to that of the MMC layer 58.0±0.2 HV.