Wear Behavior Of Aluminum Research Articles

Environmental effects on wear behaviour of alumina

The friction and wear properties of alumina (of purity 92% and 99% respectively) were evaluated at various temperatures (50, 200, 400 and 600 °C) and with an Optimal SRV (Schwingung Reibung Verschleiss) oscillation friction wear tester under loads of 15 and 50 N. In addition to atmospheric tests, dry wear tests were also performed in nitrogen at 600 °C. At 50 °C, the tribological properties of ceramics using water as a lubricant, were studied also. The important results of the present study are as follows: (1) The wear resistance of 99% alumina is better than that of 92% alumina. (2) The wear volume and friction coefficient of wear tests with water as a lubricant are lower than those in dry wear tests. (3) The friction coefficient of self-mated 92% alumina in nitrogen is slightly lower than that in the atmosphere at 600 °C, while the wear of plane specimens in nitrogen is higher than that in the atmosphere. (4) Surface polishing and abrasive wear mechanisms are dominant at lower temperature. Adhesive wear of alumina increases with increasing temperature up to 400 °C, with the exception of alumina softening at 600 °C.

Interaction between High Speed Nylon Fiber and Unlubricated Ceramic Textile Guides

The friction and wear behavior of alumina and titania textile guides in contact with high speed, dry nylon filaments has been studied using a novel, on-line, friction measuring device. The titania guides were worn very quickly to produce smooth grooves, which resulted in a large increase in fiber-guide friction. The alumina guides showed no appreciable wear during the short 1 hour tests, but a large amount of polymer deposit was produced. The morphology of the deposit was determined by the alumina guide topography. The smoother guides were smeared with polymer over the contact region. This adhesive wear process again resulted in a smoothing of the guide surface and a large rise in friction. By contrast, the rougher guides produced small particles of polymer debris by an abrasive wear process. These particles collected in a “tail region” beyond the fiber exit point. Because this did not affect the guide surface in the contact region, friction remained fairly constant during the test, but at the expense of some damage to the surfaces of the filaments. From a friction viewpoint, and if the filament damage is acceptable, this is the preferred guide surface for such an application.

The effect of alcohols and ethers on the wear behavior of aluminum

Wear in the boundary lubrication region with an aluminum-steel system lubricated with both alcohols and with aliphatic ethers was investigated under conditions of pure sliding. A pin and cylinder wear machine which provided a continuous record of wear as well as friction and metal-to-metal contact was used for the measurements. It was found that these materials react with the aluminum surface when sliding occurs and the wear mechanism is largely chemical. Higher wear rates are obtained when lubricating with alcohols than are obtained with the aliphatic ethers. Octadecanol produces a much higher wear rate than the other alcohols investigated, probably because of the lower melting point of the octadecanoL-aluminum reaction product.