1. Formability of 4j52: the alloy is easy to be cold and hot processed. Hot working temperature should not be too high, heating time should not be too long, should avoid heating in sulfur-containing atmosphere. When the cold strain rate is higher than 75%, plastic anisotropy will be induced after annealing. When the cold strain rate is between 10% and 15% and heated to 950-1050 ℃, the grain size will grow significantly, which will reduce the plasticity of the alloy, and the vacuum tightness of the metal may be lost for the thin section. Therefore, the final strain rate of the finished product should be controlled at about 60%
2. Welding performance of 4j52: the combined fittings have good welding performance and can be brazed and spot welded. This group of alloys should be pre oxidized before sealing with soft glass and other materials.
3. 4j52 parts heat treatment process: heat treatment can be divided into: stress relief annealing, intermediate annealing and pre oxidation treatment.
(1) Stress relief annealing: in order to eliminate the residual stress of parts after machining, stress relief annealing should be carried out: 430 ~ 540 ℃, holding for 1 ~ 2H, furnace cooling or air cooling.
(2) Intermediate annealing: in order to eliminate the work hardening phenomenon caused by cold rolling, cold drawing and cold stamping, so as to facilitate continuous processing. The workpiece should be heated to 700-800 ℃ in vacuum or protective atmosphere, and kept for 30-60min, then cooled in furnace, air or water.
(3) Pre oxidation treatment: when the combined gold is used as sealing material, it should be pre oxidized before sealing. A uniform and dense oxide film is formed on the surface of the alloy. The parts are heated in saturated wet hydrogen at 1100 ℃ for 30 min, and then oxidized in air at about 800 ℃ for 5-10 min. The optimum weight gain of parts is 0.1-0.3mg/cm2.