1 Manuscript No. 287 in Advanced Materials Modification of Amorphous Materials by Various Surface Modification Techniques M. Iqbal 1,* , N. Yasmin 2 , M.U. Rajput 1 , S.Z. Hussain 1 and I. Ahmad 3 1 PINSTECH, PAEC, Islamabad, 2 Nilop, Islamabad, 3 NCP, Islamabad, Pakistan  Corresponding author’s e-mail address: miqbalchishti@gmail.com Phone, 92-51-9248787, Fax, 92-51-9248808 Abstract Melt spun ribbons (MSRs) of about 20 mm width and 50 m thickness of Ni86Cr7Si4Fe3, Fe78Si13B9 and Fe75Si13B9Nb3 alloys are prepared melt spinning techniques under high vacuum. 10 mm thick bulk ingots of Zr54Cu29Ni9Al8 and Zr52Cu18Ni15Al10Ti5 alloys are prepared by Cu mold casting technique. The selected samples of appropriate size were modified by various techniques. Laser beam melting (of Zr-based alloys) results in crystallization at the modified surface while bulk sample remains still amorphous. The NiZr2 primary phase and CuZr2 metastable phase was detected in a few areas of irradiated samples of Zr54Cu29Ni9Al8 alloy. Ion irradiation by He + ions of Fe78Si13B9 and Fe75Si13B9Nb3 alloys result in partial crystallization. No significant effect on crystallization was observed in the Fe- and Ni-based alloys by neutron irradiation. Average Vicker’s hardness of the as cast and modified materials was measured. About 20-40 % improvement in hardness was observed at the modified surfaces by ion irradiation, neutron irradiation and laser beam melting. Keywords: Surface modification, microstructure, ion irradiation, neutron irradiation, laser beam melting, electron beam melting, hardness 1. Introduction Amorphous materials are new class of advanced materials with very promising physical, mechanical and thermal properties [1, 2]. Bulk metallic glasses have unique properties and better than their crystalline counter parts due to their non-equilibrium and disordered structure [3]. The surface properties of amorphous materials can be further improved by modifying their surfaces by surface modification techniques [4-13]. These techniques include ion beam irradiation, neutron irradiation, irradiation with gamma rays, electron irradiation, laser beam melting and electron beam melting [7-10]. Every technique has its own benefits and limitations. Electron and laser beam melting are usually used to modify the materials surface with high cooling rates. In ion irradiation or neutron irradiation, bulk materials remains usually amorphous while partial crystallization was observed in the modified portion of the samples. Micro hardness, nano hardness and elastic modulus improved in the modified samples [11]. Some reports are already available to modify the surface of amorphous materials by electron beam melting, laser beam melting and ion irradiation [4-13]. More work is still needed to improve the materials properties for commercial grade applications. High cooling rates are achieved by laser and electron beam melting due to localized melting with high cooling rates. Many reports are available on