Friction Characteristics of Poly Vinyl Alcohol Hydrogel Against Titanium Alloy Studied by Orthogonal Method

Poly vinyl alcohol(PVA) hydrogel was prepared from aqueous solution of the polymer by freezing and thawing method.A three-factor,two-level experiment was designed to investigate the effects of different factors on the friction and wear properties of PVA hydrogel by ball-plate friction and wear tester.Friction coefficient of the PVA hydrogel depended significantly on load and sliding speed,and lubricant had little influence on the friction.Friction coefficient decreased with the increase of sliding speed and it increased with the increase of the load.Average friction coefficient decreased from 0.038 to 0.031 while the sliding speed increased from 110 r/min to 220 r/min,and the average friction coefficient increased from 0.027 to 0.042,as the load increased from 5 N to 10 N.Wear ratio of PVA hydrogel under distilled water decreased with the increase of applied load,and the influence of load on wear rate was gradually weakened with the increase of applied load.Wear rate decreased 2.6 times when the load increased from 5 N to 10 N,whereas,it only dropped 35% when the load rising from 10 N to 15 N.