Corrosion and wear behaviour of nano Al₂O₃ reinforced copper metal matrix composites synthesized by high energy ball milling

Abstract

Copper alloys and composites find a variety of applications where wear and corrosion resistance are of paramount importance. An attempt has been made to study the behavior of copper alumina composites made through powder metallurgy. Microcrystalline Alumina (Al₂O₃) and Copper (Cu) powders were synthesized by high energy planetary ball milling to reduce their particle size to nano scale. In the present work, corrosion and wear behavior of copper MMC reinforced with different weight percentages (5, 10, 15%) of Alumina were examined and the results are presented. Powders were characterized by X-ray diffraction (XRD) to obtain the particle size of the composite powders and scanning electron microscopy (SEM) was also used to know the dominant process during each cycle of milling. Green compacts were obtained by compressing the powders into solid by placing them in a rectangular die using a universal testing machine (UTM), sintered in electric furnace and cooled. Wear and corrosion properties of the compacts were studied using Pin-on-Disc apparatus and Standard corrosion test using linear potentiodynamic polarization tester with 3.5% NaCl as per ASTM G99 standards. Best wear and corrosion values were obtained at 15% wt. % of alumina and 10% wt. % of alumina respectively.

Keywords:

• Ball milling
• wear resistance
• corrosion resistance
• XRD
• SEM