Partial surface-wear heat treatment of aluminium@ components of IC engines - by temporarily heating using high energy beam then cooling into deeper and adjoining regions

摘要

Method involves partial surface-near heat treatment of Al components of engines. Material heated temporarily to a certain temp. by short-term application of a high-energy beam is cooled down through heat conduction into its deeper and adjoining regions. Surface region to be treated is heated to produce a pattern of adjacent miniature (area-covering) melting spots, with sufficiently wide jumps (A') in this pattern, so that each successive application of the beam takes place in a region which is approximately at the room temp. Dia. (D) of melting spots is chosen equal to at least 2.5 times the focal spot dia. (f) of the beam. High-energy beam (25) moves in a circular path over each melting spot until the desired melting depth (t) has been reached. Distance (a) between adjacent melting spots is taken approximately equal to the dia. (d) of the circular beam motion. Opposite side of the component undergoing treatment is cooled by means of a flow of fluid, preferably cold air. The high-energy beam (25) can be an electron beam. USE/ADVANTAGE - Used in the motor industry. Treatment produces no changes in the surface contours and no thermal warping of the components treated.