Microstructural Evolution in Mechanical Alloying and Hot Pressing of Aluminium and 316 Stainless Steel Powder Blend
|Indranil Manna 2, Asis Samanta 4, Partha P. Chattopadhyay 4, Witold Łojkowski 3, Hans-Jörg Fecht 1,5|
1. Ulm University, Albert-Einstein-Allee 47, Ulm 89081, Germany
Mechanical alloying is a solid-state non-equilibrium mechano-chemical synthesis technique for producing nanocrystalline or amorphous metallic alloys, intermetallic phases, compounds and composites. The process involves a complex sequence of deformation, fragmentation, cold welding, dynamic-polygonization and grain refinement. Thus, milling in a planetary ball mill could simulate the microstructural changes anticipated at the surface of bulk components exposed to severe wear, erosion and mechanical deformation. Indeed, the microstructural changes associated with railroad steel during high-speed train movements could successfully be simulated by subjecting the same material to mechanical attrition (or an accelerated process of wear) in high-energy mechanical milling under predetermined conditions.
AISI 316 stainless steel and similar ferrous materials are often coated on Al based light alloys to improve wear resistance. Therefore, ball milling of pre-alloyed AISI 316 stainless steel and elemental Al powder blend in different proportion may simulate the microstructural evolution at different locations of the alloyed zones extending from the coated surface (pure stainless steel) to the underlying bulk (Al-alloy).
The present study aims to examine the phase evolution in blends comprising different proportions of stainless steel and Al (0, 25, 65 and 85 wt. %) powders during high-energy ball milling though x-ray diffraction analysis, scanning electron microcopy and high-resolution transmission electron microscopy. An attempt has also been made to study the mechanical property of the bulk samples obtained by hot pressing the ball milled powder blend at suitable temperature and pressure. In the present paper, we will present our results on the microstructural changes and mechanical property and discuss the utility of consolidation of amorphous/nanocrystalline powders by high-pressure technique to develop engineering components.
Presentation: oral at E-MRS Fall Meeting 2005, Symposium I, by Indranil Manna
See On-line Journal of E-MRS Fall Meeting 2005
Submitted: 2005-06-03 18:31 Revised: 2009-06-07 00:44