The Comparative Study On Behaviour Of Unidirectional And Reciprocating Sliding Wear At Lower Number Of Cycles

Numerous types of apparatus and test schemes exist in the domain of tribological experiment. As experimental results obtained may greatly differ caused by employing different experimental method even under the condition of the same experimental parameters, the importance of comparing distinct test scheme should not be disregarded. As the most universal experimental methods, the similarities and differences in wear process and mechanism between unidirectional sliding wear (ball-on-disc) and reciprocating sliding wear (ball-on-flat) are discussed in this thesis.Wear process of 45 steel and aluminium alloy 7075 was studied in different experimental method separately. Comparing the wear process and mechanism of unidirectional sliding wear with that of reciprocating sliding wear, the phenomenon that different material had distinct "sensitivity" toward experimental methods was noticed. The wear behaviour of 45 steel strongly related to the wear experiment method, on the contrary, different sliding motion had less influence to aluminium alloy 7075, as on the one hand, in lower cycles, the major types of wear mechanisms of 45 steel were abrasive wear and the great differences between experimental methods were attributed to the evolving mechanism of wear debris, on the other hand, the major wear mechanism of aluminium alloy 7075 was exfoliation and different experimental method had less influence to this type of wear mechanism. In a word, the degree of influence caused by different sliding mode was determined by the type of wear mechanism. Since wear mechanism was determined by character of material, wear experimental method should be carefully considered on the basis of character of material. The result of experiment may change a lot due to using different experimental method..