Experimental and theoretical analysis of wear mechanism of metals in tilted block on plate type sliding

In this investigation, the wear mechanism of metals in tilted block on plate type sliding was analyzed experimentally and theoretically. Block specimens were made of 0.45% carbon steel and tip angle of block edge was π/2 rad (90°). Plate specimens were made of 0.45% carbon steels with three different hardness and aluminium alloys with two different hardness. Attack angle of block edge a was changed from 0.025π rad (4.5°) to 0.48π rad (85.5°). All of the wear tests were carried out under mineral oil lubricated condition. Wear process was observed successively by using a Charge-Coupled Device (CCD) microscope and recorded with a Video Tape Recorder. The following results were obtained. Wear mechanisms of metals were classified into following three types: 'cutting', 'ploughing' and 'plastic deformation of block tip'. Specific wear rate of plate specimens changed drastically by the change of wear mode. A new wear map for tilted block on plate type sliding was proposed theoretically by using the attack angle α and hardness ratio r = H_plate/ H_block, where H_block is Vickers hardness of block specimen and H_plate is Vickers hardness of plate specimen. This wear map correlates well with the experimental results. The newly introduced wear map indicates that the severest wear mode of 'cutting' can be suppressed if the hardness ratio is higher than a certain critical value which can be changed by lubricated condition or attack angle.