Reciprocating Wear Behavior of Al Alloys: Effect of Porosity and Normal Load

Avijit Sinha,Zoheir Farhat,Md Aminul Islam

doi:10.15344/2455-2372/2015/117

Avijit Sinha, Zoheir Farhat + Show 1 more

Open Access

https://doi.org/10.15344/2455-2372/2015/117

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Abstract

Aluminum alloys are attractive for critical applications such as pistons, clutch housings and liners in automotive industry for their high strength to weight ratio, high corrosion resistance and good heat conductivity. These alloys can be fabricated using casting and powder metallurgy techniques in which porosity is a common feature. The presences of pores adversely affect the mechanical properties and wear resistance of these components. Not only the total area percentage of porosity influences the degradation in properties but also size, shape and interconnectivity of pores play an important role. In this study, aluminum alloys were produced using powder metallurgy technique. The amount of porosity was varied by varying compaction pressure and amount of wax added before compaction. Reciprocating wear tests (ball-on-flat configuration) were performed against AISI 52100 bearing steel ball under both low (1.5- 5N) and high (6-20N) loads. Scanning electron microscopy was employed in order to identify possible wear mechanisms. Both detrimental and beneficial effects of porosity under different loading conditions were observed. An attempt has been made to develop a relationship between pore size and distribution and wear behavior of aluminum alloys.

Highlights

Aluminum alloys are widely used in a variety of applications, including automotive, aerospace, air-conditioning equipment and home electrical appliances due to their high strength to weight ratio, high elastic modulus and good impact resistance [1,2,3,4,5,6,7,8,9,10,11]
Suh [35] observed that an increase in porosity content reduces the required length of cracks needed to link up pores which promotes delamination
For cold isostatic pressed (CIPed) specimens, surface porosity was varied by varying the amount of lubricant

Summary

Introduction

Aluminum alloys are widely used in a variety of applications, including automotive, aerospace, air-conditioning equipment and home electrical appliances due to their high strength to weight ratio, high elastic modulus and good impact resistance [1,2,3,4,5,6,7,8,9,10,11]. Deshpande and Lin [37] reported that porosity decreases wear resistance of material as a result of the no-load bearing characteristics of pores on the wear surface. For Al-6%Si alloy, both volume and surface porosity decrease with increasing compaction pressure (Figure 2).

Results

Conclusion