Argon ion bombardment(AIB) is used to improve the diamond-like carbon(DLC) films on the mechanical heart valve made from pyrolytic carbon.The DLC film is deposited by the pulsed laser deposition(PLD).The microstructure of the DLC films is investigated by the visible Raman spectroscopy and the X-ray photoelectron spectroscopy(XPS) before and after AIB,respectively;and the surface of DLC film is observed with microscope before and after AIB,respectively.The experimental results demonstrate that the AIB is una...