FRICTION AND WEAR BEHAVIOR OF TITANIUM - 6 ALUMINUM - 4 VANADIUM AND A NICKEL-BASE ALLOY (HASTELLOY C-276)

Some variables for wear and friction were investigated. Materials used for the present study were Ti-6Al-4V and Hastelloy C-276 with a low carbon steel as a mating material.; A ring on ring type of specimen contact rather than a pin on disk type was used. The effect of specimen geometry was investigated when two kinds of specimen contact were arranged. These are a partial ring type and a whole ring type.; Material properties and specimen geometry were variables for the titanium alloy and steel couple. The specimens of Ti-6Al-4V were heat-treated in different ways. Solution treatment temperature chosen for the present study were 1116(DEGREES)K, 1227(DEGREES)K, 1339(DEGREES)K, and 1394(DEGREES)K, where the beta-transus temperature is 1269(DEGREES)K.; It was found that specimen geometry is an important factor for friction and wear behavior specially when the difference in hardness between two contacting materials is large. There was a sudden increase in wear for the partial ring type of Ti-6Al-4V specimens which had been solution treated above the beta-transus temperature. No difference in wear was found for the titanium alloy and steel couple, when the titanium alloy specimens has been solution treated below the beta-transus, while the bulk hardnesses of those specimens vary significantly.; Variables of load, speed and specimen geometry were investigated for the Hastelloy and steel couple. Wear amount increases with increasing load and the slidin speed. The average coefficient of friction significantly decreases with increasing the applied load. No sudden increase in wear was observed for the partial ring type specimens as well as the whole ring type.; Wear values for the titanium alloy and steel couple were higher than those observed for the Hastelloy and steel couple. Different mechanisms take place for each couple. Smearing, smoothing, and flaking occur for the titanium alloy and steel couple, while smearing, adhering, and material transfer take place for the Hastelloy and steel couple.; A heavily deformed layer was found underneath the worn surface. It can easily be seen for the softer material since the depth of the layer is relatively large.; Temperature is not a significant factor friction and wear behavior in the range of the present study.; Wear particles generated during the test do not show the uniformity in shape. A large scatter was also found in the size of wear particles.; ; *Hastelloy C-276 is a registered trademark of Stellite Division, Cabot Corporation.