en Research Paper Research Paper In this research, infiltration behavior of W-Ag composite compacts with Nickel and Cobalt as additives has been investigated. Nickel and Cobalt were added to Tungsten powder by two distinct methods: mixing elementally and reduction of salt solution. The coated Tungsten powders were compacted under controlled pressures to make porous skeleton with 32-37 vol. % porosity. Infiltration process was carried out at 1100 ̊C under a reducing atmosphere for 1h. The effect of additives on infiltration of Ag and density were evaluated by SEM and Archimedes methods. Properties of the specimens were compared following two distinct processes namely: I) sintering simultaneously with infiltration process and II) sintering prior to infiltration (pre-sintering process). It was found that specimens which were pre-sintered and then infiltrated with molten silver represent higher hardness and finer microstructure than the specimens infiltrated simultaneously with sintering. Infiltration, W-Ag Composites, Powder Metallurgy, Mixing Elementally, Reduction of Salt Solution 8 11 http://ijmse.iust.ac.ir/browse.php?a_code=A-10-127-57&slc_lang=en&sid=1 N Parvin 180031947532846002850 180031947532846002850 No Department of Mining and Metallurgical Engineering, Amirkabir University of Technology, Tehran, Iran. R Derakhshandeh Haghighi 180031947532846002851 180031947532846002851 No Department of Mining and Metallurgical Engineering, Amirkabir University of Technology, Tehran, Iran. M Naeimi mhnaemi@gmail.com 180031947532846002852 180031947532846002852 Yes Department of Mining and Metallurgical Engineering, Amirkabir University of Technology, Tehran, Iran. R Parastar Namin 180031947532846002853 180031947532846002853 No Department of Mining and Metallurgical Engineering, Amirkabir University of Technology, Tehran, Iran. M. M. Hadavi 180031947532846002854 180031947532846002854 No Department of Mining and Metallurgical Engineering, Amirkabir University of Technology, Tehran, Iran.