Corrosion Resistance and Ease of Processing: Practical Advantages of Zinc-Aluminum Alloy Die Casting

The practical value of zinc-aluminum alloy die casting is particularly prominent in its dual characteristics of corrosion resistance and ease of processing. These two traits not only reduce the total lifecycle cost of parts but also expand their application boundaries in complex environments, making it a preferred solution in industrial manufacturing that balances cost-effectiveness and reliability.

Corrosion resistance is the core of the "environmental adaptability" of zinc-aluminum alloy die casting. Zinc-aluminum alloys (such as ZA8) contain over 90% zinc, and their surface naturally forms a dense zinc oxide protective film that prevents deep oxidation. In neutral salt spray tests, untreated zinc-aluminum alloy castings can resist corrosion for 500 hours, and this can be extended to 1500 hours after chromate passivation treatment, far exceeding the 300 hours of aluminum alloys of the same thickness. When used as connectors in marine equipment, their seawater corrosion resistance is even more advantageous: after continuous immersion in seawater for 6 months, the surface corrosion depth of a zinc-aluminum alloy shell of an oceanographic instrument is only 0.02mm, much lower than the 0.08mm of stainless steel. This characteristic allows parts to operate in humid, salt-laden environments without frequent maintenance, extending their service life by 2-3 times.

Ease of processing is reflected in the efficiency and convenience throughout the entire production chain. During the die casting stage, the fluidity of zinc-aluminum alloys is 1.8 times that of pure aluminum, enabling them to quickly fill mold cavities, even replicating 0.5mm fine gaps completely, thus reducing subsequent trimming processes. Post-molding machining is even more advantageous: their Brinell hardness is only 80-100HB, much lower than the 150-200HB of cast iron, increasing drilling efficiency by 40% and reducing tool wear during tapping by 50%. In the processing of zinc-aluminum alloy housings for an electronics company, high-speed milling (1500r/min) can directly achieve a surface roughness of Ra1.6μm, eliminating the need for polishing and shortening the processing time per unit from 12 minutes to 8 minutes.

The superposition of these two characteristics creates a synergistic effect. Corrosion resistance simplifies protective treatments—after die casting, parts only require simple passivation to meet general working conditions, without the need for additional electroplating or painting. Ease of processing reduces molding difficulties; complex structural parts can be die-cast in one piece, avoiding corrosion risks caused by multi-component assembly. For example, in bathroom hardware, zinc-aluminum alloy die-cast faucet bodies have no seams, reducing gaps that trap dirt and eliminating corrosion-prone points from welding. Combined with chrome-plated surfaces, their service life can exceed 10 years.

From outdoor power equipment to bathroom products, from marine instruments to consumer electronics, zinc-aluminum alloy die casting resists environmental erosion with its corrosion resistance and simplifies manufacturing processes with its ease of processing. This practical advantage of being "durable and easy to manufacture" allows parts to ensure reliability while significantly reducing production and maintenance costs, making it an ideal choice in the industrial sector that balances performance and economy.