ABRASIVE WEAR STUDY OF AA7075/ZrB2 REINFORCED COMPOSITES

AA7075-xZrB(2) (x = 0, 5, 10, 15, and 20 wt.%) composites were manufactured by reacting potassium zirconium fluoride (K2ZrF6) and potassium tetrafluoroborate (KBF4) with molten AA7075 at 800 degrees C. The ZrB2 particles formed by the reaction were fairly uniformly distributed throughout the whole composite. The microhardness of the composites increased from 45 to 78 VHN with ZrB2 contents from 0 to 20 wt.%, respectively. The wear rate rose as the load and sliding distance increased and fell as the sliding speed increased. The material-removal mechanism of the composites was due to abrasive wear.