Cost Effective And Qualified Solution for Thin Wall Aluminum Component Machining

Cost effective and qualified Solution for thin wall aluminum component machining

Aluminum alloys are widely used in aerospace, automotive manufacturing, and precision component manufacturing due to their excellent thermal conductivity and corrosion resistance. The most common aluminum alloy used are 6061 and 7075.

The hardness of the Aluminum ranges from HB60-120 AND the break strength is bigger than 275Mpa and yield strength is not less than 240 Mpa.

During the machining process of parts, deformation often occurs due to residual stresses, particularly when processing non-ferrous light metals such as aluminum and magnesium alloys. Deformations like warping, bending, and twisting caused by residual stresses frequently appear, severely impacting part quality and machining efficiency—especially for thin-walled and thin-plate components. How to minimize or eliminate part deformation to ensure product quality and production efficiency has been a long-standing focus of our research.

To enhance the machinability and service properties of aluminum alloys, heat treatment (quenching + aging) is required prior to machining to increase strength. During quenching, significant internal stresses develop within the material. The aging process cannot fully release these quenching stresses. Subsequent machining generates new cutting stresses. As material is progressively removed, the equilibrium state of internal stresses is disrupted. These stresses redistribute until a new equilibrium is reached, causing deformation that compromises the part's machining accuracy. Furthermore, when surface stresses exceed the material's strength limit, cracks may form.

For thin-walled and thin-plate aluminum alloy parts, the “hollowing-out” method is employed for machining. The “hollowing-out” method involves completing all dimensional machining in a single setup before extracting the part from the blank. The hollowing-out process includes: milling the top surface → rough milling the internal cavity → rough milling the outer contour → finish milling the outer contour → finish milling the internal cavity → finish milling the bottom surface → drilling holes → cutting off, etc. Since the entire process is completed in a single setup, the part remains connected to the blank material at the bottom surface prior to cutting. This prevents significant deformation caused by internal stresses, ensuring dimensional stability throughout. During cutting, a 0.1mm bond between the blank material and the part material at the bottom surface is required. This bond guarantees sufficient strength for the part to withstand the cutting stresses generated during the entire “hollowing-out” process.

The “hollowing-out”  method is now widely applied in the batch production of aluminum alloy structural components at our factory. This approach not only enhances machining efficiency and product quality but also eliminates errors caused by misalignment between design and process benchmarks. By completing all dimensional machining in a single setup, it prevents tolerance compression due to dimensional chain conversions, simplifies the process specification development, and streamlines the part machining process.