Wear and Corrosion Investigation on the Electrodeposited Ni-P Coating

Abstract

The wear and corrosion characteristics of an electrodeposited Ni-P coating were studied using a block-on-ring wear tester. The testing environments included dry wear and immersion wear in a 5 wt% NaCl water solution bath to simulate the corrosive atmosphere. The wear behavior is discussed in terms of the friction coefficient, wear rate, and surface roughness. Under boundary lubrication, the wear mechanism changed from both adhesive and abrasive wear for dry contact to mostly abrasive wear in corrosive salt water. The corrosion pits and corrosion film formed during accelerated corrosion wear testing not only lowered the friction coefficient but decreased the surface roughness. However, due to the accelerated pitting corrosion and removal of the corrosion film, the weight loss was slightly increased. Finally, the X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM) analyses confirmed the formation of a porous corrosion film after the wear test in salt water.

KEY WORDS:

• Nickel
• Friction Mechanism
• Corrosion

ACKNOWLEDGMENT

Partial financial support from the National Science Council, Taiwan, under Grant Nos. NSC 98-2221-E-027-MY3 and NSC 99-2221-E-212-003 and the Ministry of Economic Affairs under Grant No. 99-EC-17-A-16-S1-127 is acknowledged.

Review led by Tom Karis