Investigations of Wear and Corrosion on Ti6A14V Alloy Treated by Nickel in wet Conditions and PVD Duplex Coatings in Dry Condition

Abstract

Titanium alloys are well known as difficult-to-machine materials due to their newlinechemical affinity, low thermal conductivity and low modulus of elasticity, causing newlinepremature wear of the tool, compromising the machining quality and increasing costs. newlineSince its first introduction in the 1950s, Ti6Al4V became the most sympathetic newlinetitanium alloy due to its attractive mechanical and physicochemical properties and is newlinecurrently extensively used e.g. machining, automotive, aerospace as well as newlinebiomedical industry. However, its poor tribological properties limit its use in newlinemachining, automotive, aerospace and orthopaedic applications. Hence, a variety of newlineattempts have been made in order to improve tribological performance of titanium newlinealloys, especially focusing on surface modification. newline In this work Ni coating and PVD coatings mainly nitride based care tested to newlineimprove the wear, coefficient of friction, corrosion of Ti6Al4V alloy. Nickel coating newlineof 40 microns thickness was done by electroless plating method The tribological newlinebehaviour is evaluated at room temperature in wet lubricated conditions on pin-on- newlinedisk equipment, by testing coated pins of 10 mm diameter against EN31 flat plate. newlineNickel coating were performed on a titanium alloys for duration of 5, 7.5 and 10 newlineminutes for load of 50 N, 60 N, 70 N, 80 N, 90 N and 100 N with disk speeds of 400 newlinerpm, 500 rpm, 600 rpm, 700 rpm 800 rpm and 900 rpm. Friction coefficient of coated newlinepins in wet condition is observed to be less, as compared to the tests performed with newlineuncoated pins. Coated sample tested in lubricated condition showed much more newlinereduction in wear and friction coefficient than their performance under uncoated newlinecondition. From experimental investigation, it is observed that the Ti alloys with Ni newlinecoating shows improved wear rate and friction coefficient as compared to base newlinematerial newline