The fundamental reason for the different materials used in die castings for outdoor and indoor lighting fixtures lies in their distinct operating environments, which impose varying quality requirements on the products. Indoor lighting fixtures are exposed to a mild environment (with minimal erosion from rainwater and ultraviolet rays), so the focus is more on cost control, processing convenience, and basic appearance performance. Therefore, indoor lighting fixtures typically use zinc alloys or aluminum alloys: Zinc alloys offer excellent fluidity in die casting, making them suitable for complex lamp housing designs, and their surfaces can be polished, electroplated, etc., to meet the sophisticated appearance needs of indoor lighting. Aluminum alloys, on the other hand, are more affordable and lightweight, making them ideal for brackets or hidden components of indoor downlights and ceiling lights.
Outdoor lighting fixtures, however, are long-term exposed to erosion from wind, rain, ultraviolet rays, temperature fluctuations, and other factors, so they have high requirements for corrosion resistance and structural stability. As a result, aluminum alloys with stronger weather resistance are preferred for outdoor lighting. Zinc alloys, by contrast, are rarely used in outdoor lighting die castings because they are prone to oxidation and rusting when exposed to the outdoor environment for extended periods.
