| 摘要 |
PURPOSE:To provide complete metallic binding of aluminum pipes, by plating the inner pipe with zinc and nickel with a thickness of 1-5mu and 5-10mu respectively and heating the juncture by applying high frequency from outside. CONSTITUTION:An inner pipe 2 plated with zinc and nickel is inserted by a certain length after pickling in a pipe 1 slightly expanded at an end to make a cap. As the assembly undergoes high frequency heating, only the outer aluminum pipe is heated up to near the melting point at the juncture. Then the crystal lattice there of the outer pipe contacting the nickel layer 14 produces a violet thermal vibration, partly being changed into a state where oxides are easily fluidized, and an instantaneous pressure completely destorys the surfacial oxidized film to form a nickel-aluminum alloy layer 16 for metallic binding between both pipes.
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