Fusing (Heat Cohesion)

Metal joint is classified into 3 categories:
Melt welding is to melt metals to joint together. Solid-phase joint is to joint solids each other. Brazing is to joint metals using lower-melting-point auxiliary material.

Resistance welding belongs to melt welding; solder joint, brazing; however, fusing, solid-phase joint.

Fusing is to flow a current through a lead wire to remove coating, making the lead conductive; then pressure is exerted onto terminal and naked lead for heat cohesion, ensuring joint strength.

Fusing is environmentally friendly joint using no solder.

Principle of fusing
(1) Flowing current generates Joule heat in electrode to soften hook, which is deformed by the electrode force.

(2) The hook heats covered lead to remove coating, causing conductor to be exposed.

(3) Current also flows in the conductor, resulting in heat-pressure joint.

Kind of fusing
Hook type
Holds lead in U-shaped terminal to joint.

    

Slot type
Stuffs leads into slot of commutator to make them cohere.

Remarks on fusing
Correct settings of such as current, electrode force are important to deform terminal and remove coating.
Clamp electrode at a certain position to keep the generated heat constant; grind or replace electrode as necessary.
2-stage current applying is common, deforming terminal in WELD 1 stage, and removing coating in WELD 2 stage.
Preferably, shape the terminal prior to processing for easy and stable fusing.

Example practical use
Fusing of motor terminal and winding terminal are popular uses.

Hook type

Slot type