Abstract: A method for desensitizing a metal alloy such as an aluminum (Al) alloy is presented. The surface of the alloy is treated by controlled laser beam irradiation. The scanning laser beam heats the alloy to reach a relative low temperature between a solvus temperature and a soften/annealing temperature of the metal alloy to controllably reduce the degree of sensitization (DOS) of the metal alloy. The locally rapid heating and cooling effects produced by scanning the laser can improve the future sensitization resistance of the metal alloy, reduce the average desensitization temperature applied, and maintain the mechanical properties of Al alloy at the same time.

Abstract: An exemplary air heat exchanger is an engine configuration including a front heat exchange unit including a front air-to-air intercooler configured to receive a stream of air, and a front radiator connected to the front air-to-air intercooler. The engine configuration also includes a rear heat exchange unit including a rear radiator and a rear air-to-air intercooler connected to the rear radiator. An internal combustion engine is located such that the rear air-to-air intercooler is located between the engine and the front air-to-air intercooler.

Abstract: An air heat exchanger comprising a front-end heat exchanger (101), a fan (8), a ventilating duct (11), a back-end heat exchanger (102), a fan power source (20) and a fan drive shaft (7), wherein the front-end heat exchanger (101) and the back-end heat exchanger(102) are connected in series by a heat exchanger connecting tube (105); the front-end heat exchanger (101) and the back-end heat exchanger (102) can each consist of one or more overlaid heat exchange units, respectively arranged upstream and downstream of a fan channel; the fan (8) is set up inside the ventilating duct (11) of the heat exchanger, adopting two-process cross-flow and counterflow heat exchange. The air heat exchanger features a simple structure, mature technology, high heat exchange efficiency, a compact structure and a fan with low power consumption and a low noise level, and of low cost.