TITLE:
Effect of Surface Porosity on Tribological Properties of Sintered Pure Al and Al 6061
AUTHORS:
Avijit Sinha, Zoheir Farhat
KEYWORDS:
Aluminium, Powder Metallurgy, Microstructure, Porosity, Wear
JOURNAL NAME:
Materials Sciences and Applications,
Vol.6 No.6,
June
24,
2015
ABSTRACT: Due to light weight, high specific strength, high corrosion resistance and good heat transfer ability,
aluminium alloys are becoming attractive for critical structural applications. These alloys can be
manufactured using powder metallurgy techniques in which porosity is a common characteristic.
The presence of pores is responsible for decreasing effective load bearing cross sectional area and
inducing stress concentration sites for strain localization and damage, decreasing both strength
and ductility. The present study aims to establish a better understanding of the relationship between
surface porosity and corresponding wear behavior. In this study, porous specimens were
produced using powder metallurgy technique and the extent of wear damage and the type of wear
was investigated under low load range of 1.5 - 5 N against AISI 52100 bearing steel ball using a reciprocating
ball-on-flat configuration and frequency of 10 Hz. Scanning electron microscopy of the
wear tracks and wear debris was carried out to understand wear mechanisms. This study revealed
that due to combined effect of high stress intensity and subsurface cracking, wear rate increases
with increasing porosity content. The friction and wear behavior of pure Al and Al 6061 as a function
of porosity content can be attributed to their hardness and corresponding wear mechanism.