Time resolved friction during dry sliding of metal on metal

In the present study, plate impact pressure-shear friction experiments are conducted to provide insight into time-resolved dry sliding characteristics of metal on metal at normal pressures of approximately 1.5 GPa, slip speed s up to 60 m/s and interfacial temperatures as high as 800 degrees C, The p late impact friction experiments represent a significant improvement over c onventional dynamic friction experiments by allowing control of interfacial tractions with the use of combined pressure-shear loading waves instead of manipulating actuator motion. Also, by measuring the combined normal and t ransverse motion of the rear surface of the target plate, critical friction al parameters such as the applied normal pressure, the interfacial slip res istance, and the interfacial slip speeds can be interpreted by using the fr amework of one-dimensional plane wave analysis. The experiments are conducted on a Carpenter Hampden tool-steel (D3)/Ti-6Al -4V tribe-pair. The frictional state at the tribe-pair interface is varied by varying the impact velocity and/or the surface roughness of the impactin g surfaces. Moreover, by appropriate selection of flyer and target plate th ickness the tribe-pair interface is subjected to step changes in normal pre ssure and step changes in applied shear stress. The results of these experi ments provide new insights into the evolution of interfacial sliding resist ance with accumulated interfacial slip, and its dependence on surface rough ness, slip velocity, normal pressure and interfacial temperature. (C) 2000 Elsevier Science Ltd. All rights reserved.