Characterization of low alloy steel impregnated with WS2 using nano-indentation
Suresh R. Ambalam, Rajendran I. Gounder
Volume 2, Issue 3, Page 140-145, Year 2017 | DOI: 10.5185/amp.2017/302
Keywords: Nano-indentation, powder metallurgy, low alloy steel, solid lubricant, phase transformation.
Abstract: Low alloy steel is used in industrial applications to manufacture bearing materials, bushes, gears, etc. In this work, an attempt has been made to characterize powder metallurgy (PM) processed low alloy steel impregnated with solid lubricant WS2 in four different weight proportions (0, 2.5, 5 and 10%) using nano-indentation. Results of nano-indentation were correlated with impregnated quantity of WS2 and micro structural phases in sintered low alloy steel. The values of elastic moduli and contact stiffness were found to be higher in the PM-processed low alloy steel impregnated with WS2 compared with the low alloy steel without WS2. Ferritic and pearlitic phases in the microstructure were observed in low alloy steel impregnated with 0 % WS2. Larger proportion of martensitic phase was observed in the microstructure of low alloy steel impregnated with 5 and 10 % of WS2. The specimen with 2.5 % WS2 by weight has the highest hardness and the highest elastic modulus of all the proportions tested, which may be attributed to predominant bainitic structure present in it. Hence the PM-processed low alloy steel impregnated with 2.5 % WS2 would be more suitable composition for manufacturing sliding members due to its superior mechanical properties. Copyright © 2017 VBRI Press