Applies the finishing manner and its finishing manner of the titanium component the coil spring

摘要

PURPOSE:To improve the wear resistance and fatigue strength of a Ti member at a low cost by subjecting the surface of the Ti member to electroless Ni plating, annealing the member at a specified temp. and carrying out shot peening. CONSTITUTION:The surface of a Ti member is subjected to electroless Ni plating to uniformly and firmly form an Ni coating layer without causing hydrogen brittleness. The Ni coated Ti member is annealed at 250-450 deg.C. By this annealing, P, B, etc., are precipitated as Ni3P, Ni3B, etc., from the Ni coating layer to increase the hardness and to improve the wear resistance. The Ni coating layer is then subjected to shot peening to produce compressive residual stress. The occurrence and growth of fatigue cracks in the surface of the Ti member is inhibited and the fatigue strength is improved.