PURPOSE: To smoothly and surely manufacture a lead bar by drawing a material with copper material covered with nickel material, welding both of them with pressure then performing post heat-treatment and executing diffusion joining of the boundary between the copper material and the nickel material.
CONSTITUTION: A columnar copper material 1 and a columnar nickel material 2 having an inner diameter a little larger than the diameter of the material 1 are prepared in advance and cold drawing is carried out with dies in a state the nickel material 2 is put on the outer periphery of the copper material 1. In this case, ≥30% cold working ratio (reduction ratio in area is applied). Then, after this intermediate material is degreased, heat treatment is executed in sequence by a continuous heat treatment furnace. Heat treatment is executed under the conditions set to 500-100°C temperature and ≥30min treatment time. In this way, sufficient diffusion joining is realized on the interface between the copper material and the nickel material and deterioration of quality such as coarsening of grains can be prevneted.
ENDO HARUMICHI
HAMADA KAZUICHI
| JPS61219415A | 1986-09-29 | |||
| JPH02152182A | 1990-06-12 |