Aluminum alloy plate for washing machine
Aluminum alloy sheet for washing machines is a material specifically designed for use in washing machine components such as inner and outer drums, panels, and more. It boasts lightweight, corrosion resistance, easy formability, and affordable cost, making it widely used in both front-loading and top-loading washing machines. Key grades include 3003, 5052, and 6061. 3003 aluminum alloy contains 1.0-1.5% manganese, offering excellent corrosion resistance and weldability, making it suitable for inner drums. 5052, with a magnesium content of 2.2-2.8%, offers high strength (tensile strength ≥230 MPa) and is used in outer drums. 6061, containing magnesium and silicon, can be heat-treated and strengthened, making it suitable for load-bearing components such as brackets. Sheet thickness ranges from 0.8-3mm and widths range from 800-1500mm. The surface undergoes passivation or electrophoresis treatment, offering salt spray resistance of ≥1000 hours and resistance to long-term corrosion from detergents and water.
The production process for aluminum alloy sheets for washing machines requires a balance between formability and corrosion resistance. First, high-purity aluminum ingots (99.7%) and alloying elements are selected and smelted in a furnace at 720-750°C. Impurities are removed through online degassing (hydrogen content ≤ 0.15 ml/100 g Al) and filtration. Ingots are cast semi-continuously to a thickness of 300-500 mm and subjected to homogenization annealing (400-500°C) for stress relief. The sheet is hot-rolled to a thickness of 6-10 mm and cold-rolled to the target thickness. Intermediate annealing is performed at 300-400°C, with a hardness controlled between HV50-80 to ensure stamping performance. Surface treatment includes chromate passivation (film weight 5-10 mg/m²) or chromium-free passivation to enhance corrosion resistance. Some products are coated for enhanced wear resistance. Finished products undergo flatness testing (deviation ≤ 2 mm/m) and tensile testing (elongation ≥ 15%) to ensure they meet washing machine manufacturing requirements.
In front-loading washing machines, aluminum alloy plates are the core material for both the inner and outer drums. The inner drum is constructed from 0.8-1.2mm thick 3003 aluminum alloy plates, spin-formed to create a honeycomb structure. The surface is electrolytically polished (Ra ≤ 0.2μm) to minimize wear and tear on clothing. The inner drum of a certain brand of front-loading washing machine boasts a service life of over 10 years. The outer drum is constructed from 1.5-2mm thick 5052 aluminum alloy plates, welded into a sealed chamber that withstands corrosion from 80°C hot water and detergents. One manufacturer’s outer drum leakage rate is kept below 0.05%. The front panel is constructed from 2-3mm thick 6061 aluminum alloy plates, anodized for both aesthetics and wear resistance. The panel of a high-end washing machine achieves a 4H scratch resistance rating.
The use of aluminum alloy plates in pulsator washing machines prioritizes lightweighting and cost control. The pulsator disc is constructed from 1-1.5mm thick 3003 aluminum alloy plates, which are balanced after stamping to ensure an amplitude of ≤0.5mm during rotation. This reduces noise levels in one brand of washing machines to 55 decibels. The cabinet frame is constructed from 5052 aluminum alloy plates, which are bent and welded to form a load-bearing structure. This reduces weight by 30% compared to steel plates, reducing shipping costs for one manufacturer’s washing machines by 12%. The control panel bracket is constructed from 6061 aluminum alloy plates, CNC-machined to ensure installation accuracy (±0.1mm), improving panel assembly efficiency by 20% for one model of washing machines.
As washing machines evolve towards energy-saving and intelligent features, the performance of aluminum alloy plates continues to improve. Manufacturers have developed antibacterial aluminum alloy plates (with added silver ions) that inhibit E. coli by ≥99%, reducing bacterial residue in a particular washing machine by 80%. Heat -resistant aluminum alloy plates, specifically designed for the high-temperature environments (95°C) of heat pump washing machines, have been developed. These plates retain ≥90% of their tensile strength under long-term high temperatures, reducing the high-temperature wash failure rate in a particular brand of washing machine by 40%. Laser welding technology has been employed to increase the strength of the inner drum joints by 30%, further reducing the risk of leaks. In the future, as lightweighting and environmental protection requirements increase, aluminum alloy plates for washing machines will move towards thinner gauges (0.5-0.8mm) and higher corrosion resistance (≥2000 hours of salt spray resistance). The industry will also explore the use of high proportions of recycled aluminum to promote green transformation.
