Spray forming: An energy saving and process efficient technique

Spray forming technique has attracted considerable attention, not only from the standpoint of metallurgical advantages, but also as a potential for near net-shape fabrication with energy and cost savings. In this paper, principles, processes and industrial practices of spray forming to manufacture different geometry parts (i.e., plates/strips/sheets, billets/rods, tubes/rings, etc.) are reviewed and compared with those of conventional ingot metallurgy (I/M) or continuous casting and powder metallurgy (P/M) techniques. The factors related to energy efficiency (i.e., reduction of operation steps, deposition yield and inert gas consumption) are overall analyzed and equipment investments are evaluated in spray forming. They are compared with those in conventional I/M or continuous casting and P/M techniques. The results reveal that, energy consumption and capital and labor costs can be significantly saved using spray-forming technique as a result of reduction in operation steps. In order to improve the competitiveness of spray-forming technique with conventional I/M or continuous casting and P/M techniques, the approaches to continuously spray form different geometry parts (i.e., plates/strips/sheets, billets/rods, tubes, etc.) are introduced. In addition, the principle of spray forming for the fabrication of complex molds/dies is reviewed. Similarly, production cost and time can be significantly reduced, compared with the conventional fabrication procedures for molds/dies.