Preparation method of K477 expansion sealing fin for selective laser melting forming engine

The invention provides a preparation method of a K477 expansion sealing fin for a selective laser melting forming engine, which comprises the following steps: A) screening K477 alloy powder, and drying to obtain dry powder; b) performing selective laser melting forming on the dry powder to obtain a formed expanded sealing fin part; and C) sequentially carrying out annealing, solution treatment and aging treatment on the molded expanded sealing fin part to obtain the K477 expanded sealing fin for the engine, the solid solution treatment is carried out in an argon atmosphere, the temperature of the solid solution treatment is 1150-1170 DEG C, a mode of entering a furnace at the temperature is adopted, and the heat preservation time of the solid solution treatment is 108-132 minutes. By means of the selective laser melting technology, the optimal forming process parameters and the heat treatment system are selected, the technical problem that in the prior art, cracks are prone to occurring in parts in the select