Amorphous metal-metal composite article, a method for producing the same, and a torque sensor using the same

An annular amorphous metal-metal composite body fixed to a reinforcing member, said composite body comprising:

• an annular metal member;
• and
• an amorphous metal bonded to an outer periphery of the annular metal member by explosion bonding;
• said composite body being heat treated to remove a residual stress in the amorphous metal resulting from said explosion bonding;
• wherein said heat treated composite body is fixed to said reinforcing member through fitting, such that a tensile stress is imposed upon the amorphous metal in an amount sufficient to offset a compression stress which inherently occurs in the amorphous metal during cooling after the heat treatment.

A method for producing an amorphous metal-metal composite body, comprising:

• explosion bonding an amorphous metal to a metal member to form a preliminary composite body;
• heat treating the preliminary composite body to remove residual stress in the amorphous metal resulting from the explosion bonding;
• plastic working the heat treated preliminary composite body to impose a tensile stress upon the amorphous metal;
• and
• cooling the heat treated preliminary composite body to form said amorphous metal-metal composite body, whereby a compression stress inherently occurs in the amorphous metal during cooling;
• wherein the tensile stress is imposed upon the amorphous metal in an amount sufficient to offset the compression stress in the amorphous metal resulting from the cooling step.

A method for assembling an amorphous metal-metal composite body to form an assembly, comprising:

• explosion bonding an amorphous metal to a metal member to form a composite body;
• heat treating the composite body to remove residual stress in the amorphous metal resulting from the explosion bonding;
• and
• assembling the heat treated composite body into said assembly, such that a tensile stress is imposed upon the amorphous metal;
• and cooling the assembly, whereby a compression stress inherently occurs in the amorphous metal;
• wherein the tensile stress is imposed upon the amorphous metal in an amount sufficient to offset the compression stress resulting from the cooling step.