Effect Of Process Parameters On Particle Size Distribution Characteristics Of Tungsten Powders Reduced By Powder Metallurgy Route

Document Type : Primary Research paper


1 Department of Metallurgical Engineering PSG College of Technology, Coimbatore 641004, India

2 Kennametal India Private Limited Bangalore 560073, India


The control of particle size distribution of tungsten powders is one of the key
strategies in improving the performance of tungsten carbide powders for cutting tool
applications. For example, grain coarsening of WC powders depends primarily on the
prior grain size of tungsten powders during carburization. In this present work, effect of
process parameters on reduction mechanism (Chemical vapour transport) of tungsten
oxide to metallic tungsten has been extensively investigated, so as to control the uneven
grain growth as well as to reduce the distribution span of the particle size to obtain the
homogenized microstructure in the final sintered product. Various processing parameters
such as powder layer thickness, hydrogen gas flow rate, powder feed rate and temperature
have been modified in the trail experiments. Microstructural analysis was performed based
on particle size distribution (PSD) and the average grain size of the reduced tungsten
powders. These experimental findings can be implemented for cost effective feasible
solution in high volume production unit of powder metallurgical industries.