Chrome-free surface passivation for aluminum alloys
Applications of Aluminum Aluminum is the most productive and widely used metallic material among non-ferrous metals. It is second only to steel in terms of production of structural metallic materials. All-aluminum engines The advantage of cast aluminum blocks in die-casting production is their light weight, which enables fuel savings through weight reduction. In an engine of the same displacement, the use of an aluminum block engine reduces weight by about 20 kilograms. For every 10% reduction in the car's own weight, fuel consumption can be reduced by 6% to 8%. Disadvantages of chromate surface treatment The waste tank liquid of chromate treatment method contains a large amount of hexavalent chromium ions, and according to GB 8978--1996 Comprehensive Sewage Discharge Standard, the concentration of hexavalent chromium in the waste tank liquid is not more than 0.5mg/L. However, hexavalent chromium ions have carcinogenic effect on human body. Long-term exposure to hexavalent chromium compounds can lead to...