Zinc and aluminum die casting is a powder die casting of zinc as the main component parts. This part is a layer of very dense surface layer, which is evacuated porous structure. You can not use acidic degreasing agent, and can only use alkaline degreasing agent for degreasing. Most of the copper-zinc-aluminum parts are nickel-chromium multilayer coatings need for a higher decorative requirements. Skim through the mechanical polishing of the former are. Nickel oxide So to wax (polishing paste containing paraffin) is the first step, then the chemical degreasing and electrolytic degreasing.

 Since the melting point of paraffin wax is 70% or more, Zinc oxide in order to emulsify paraffin wax water temperature higher than 70 ℃ to be effective. In the past people just use ordinary chemical degreasing fluid to raise the temperature to wax. This method a long time and low efficiency. There is a special wax water supply, shorter is better. If ultrasound is better. Generally wax wax not only skim the water, but also to conduct chemical degreasing. The chemical activity of zinc alloy strong alkaline chemical degreasing fluid is not too strong, otherwise it will corrode the surface. Temperature is controlled at between 50 ~ 70 ℃, time 3 ~ 5min. Supply of products on the market there will be fat and wax into one of the degreasing agent, and works well with the ultrasound.

 Electrolytic zinc alloy parts degreasing agent and chemical composition similar degreasing agent. But it must contain complexing agent to use. When the electrolytic degreasing, zinc alloy die castings to skim on the cathode, the temperature at 50 ~ 70 ℃, current density of 3 ~ 5A/dm2, time 1 ~ 2min.

 In addition to wax and fat combo selection process, Magnesia the effect of the ultrasonic casting surface may sometimes be brown corrosion film. This degreasing agent should not be used. Should be replaced dedicated to zinc die castings degreasing agent. This should be special attention. Source:http://www.mhcocm.com