Mechanical properties of ion-implanted polycarbonate

The technique of ion implantation was employed for improving surface hardne ss and wear resistance of polycarbonate (PC). The samples of PC were implan ted separately with C, Al, Ti, Fe and Ni ions to four doses of 2 x 10(15) i ons cm(-2), 1 x 10(16) ions cm(-2), 5 x 10(16) ions cm(-2) or 1 x 10(17) io ns cm(-2). Wear tests showed that the wear-resistance of PC was improved si gnificantly and the friction coefficient was reduced after ion treatment, 2 x 10(15) ions cm(-2) C ion implantation produced the largest improvement i n wear-resistance by a factor of 19 times and the friction coefficient was reduced by 20%. The nano-hardness increased from 0.283 GPa for the pristine PC to 0.712 GPa for 2 x 10(15) ions cm(-2) C-implanted PC and 1.032 GPa fo r 1 x 10(16) ions cm(-2) Ni-implanted PC. TRIM96 calculation revealed that ionization energy loss, vacancy energy loss and the difference in the energ y loss for ionization and vacancies of Ni near the surface were more than t hose of the four other ions, and this was related to the largest improvemen t of surface hardness for Ni ion implantation. IR spectra of 2 x 10(15) ion s cm-2 C-implanted PC indicated that the surface of samples was moisture-re tentive and formed a new carbonyl group. (C) 2001 Elsevier Science B.V. All rights reserved.