Methods for joining dissimilar metal parts

Abstract

This invention relates to a method for joining dissimilar metal parts, comprising providing a first metal part and a second metal part, wherein the surfaces of the first metal part and the second metal part have been nano-treated; performing an injection molding process, which includes a mold assembly forming a cavity, placing the first metal part and the second metal part into the cavity, and maintaining a compression gap in the mold assembly as the compression stroke of the mold assembly, during which a plastic is injected into the cavity by embedding injection, i.e., filling the space between the first metal part and the second metal part; then applying a compressive force to the mold assembly, forcing the mold assembly to gradually close, and applying a uniform closing pressure to the plastic in the cavity, and completing the filling of the cavity by compression molding, so that the first metal part and the second metal part become a joined part; finally, opening the mold and removing the joined dissimilar metal parts.

Claims

1. A method for joining dissimilar metal parts, comprising: a. Provide a first metal part (21) whose surface has been nano-treated to form a nanostructure; b. Provide a second metal part (22) whose surface has been nano-treated to form a nanostructure; c. Perform an injection molding process, which includes a mold assembly (30), the mold assembly (30) having a first male mold (31), a second male mold (32) and a female mold (33), and together forming a cavity (34). First, open the mold assembly (30) to the open state, and place the first metal part (21) and the second metal part (22) into the cavity (34) of the mold assembly (30), and leave a compression gap (S) (not completely closed) between the second male mold (32) and the female mold (33) as the compression stroke of the second male mold (32); at this time, perform injection molding, and inject a plastic (35) into the cavity (34), that is, fill the space between the first metal part (21) and the second metal part (22); d. Next, the mold assembly (30) is compressed and molded, which provides a compressive force (P) on the second male mold (32), causing the second male mold (32) to gradually close until the mold assembly (30) is completely locked; during the displacement, the second male mold (32) applies a uniform closing pressure to the plastic (35) of the cavity (34), and the cavity (34) is filled by compression molding, so that the first metal part (21) and the second metal part (22) become tightly bonded; wherein During the injection molding process, the mold closing time of the mold assembly (30) is delayed so that the mold assembly (30) is fully closed only after the plastic (35) is injected into the mold cavity (34). The second male mold (32) provides uniform compression force so that the required flow space (T3) of the plastic (35) is less than 0.8mm, thereby significantly reducing the stacking thickness (T4) of the combined dissimilar metal parts and avoiding stress deformation; and e, the mold assembly (30) is opened to remove a combined dissimilar metal part (23).

2. The method for joining dissimilar metal parts as described in claim 1, wherein the joined dissimilar metal parts (23) after removal can be painted (24) to achieve a seamless appearance.

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