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提高铝活塞环槽表面强度的方法有多种 ,再熔化强化工艺是目前最有发展前途的一种提高铝活塞使用寿命的工艺方法。它是利用等离子弧、氩弧、电子束、激光的高温 ,重新熔化铝合金活塞环槽区一定体积的金属并同时渗入合金元素 ,在活塞环槽区形成铝基新合金 ,它同活塞体形成可靠的冶金结合 ,然后在此环形区车削活塞环槽 ,达到提高铝活塞使用寿命的目的。本文采用横流 5KWCO2激光器对HBS32 0铝活塞环槽两岸直接进行镍基合金粉末激光合金化的试验研究 ,获得了无气孔、裂纹、组织细小均匀的合金化层。SEM研究表明合金化层与基体铝合金形成了牢固的冶金结合 ,合金化层组织为靠近基体铝合金的具有定向凝固特征的树枝晶 +细小均匀的等轴晶 ,组织过渡均匀。表面硬度达到 6 5 0HV ,是基体铝合金的 5～ 6倍 ,实际使用表明 ,使用寿命较未经处理的铝活塞得到较大提高。
There are many ways to improve the surface strength of the aluminum piston ring groove, and the remelting strengthening process is the most promising method to improve the service life of the aluminum piston. It is the use of plasma arc, argon arc, electron beam, high temperature laser remelting aluminum alloy piston ring groove area of a certain volume of metal and at the same time infiltrated alloying elements in the piston ring groove area to form a new aluminum-based alloy, which forms with the piston body Reliable metallurgical bonding, and then ring in the annular piston ring groove, to improve the life of aluminum piston purposes. In this paper, a cross-flow 5KWCO2 laser was used to directly study the laser alloying of Ni-based alloy powders on both sides of the HBS32 0 aluminum piston ring groove. The alloyed layers with no pores, cracks and small and uniform microstructure were obtained. SEM studies show that the alloying layer forms a solid metallurgical bond with the matrix aluminum alloy. The alloyed layer is dendrite + fine uniform equiaxed grains with directional solidification close to the matrix aluminum alloy, and the microstructure transitions evenly. Surface hardness of 6 5 0HV, is the base of the aluminum alloy 5 to 6 times, the actual use shows that the service life of the aluminum piston has been greatly improved.