CAMX 2018 preview: DWA Aluminum Composites USA
Appears in Print as: 'Aluminum metal-matrix composites'
DWA Aluminum Composites USA Inc. (Chatsworth, CA, US) is exhibiting powder-metallurgy-based aluminum metal-matrix composites (Al MMCs), a family of advanced materials used for demanding aerostructural applications in civilian and defense platforms.
DWA Aluminum Composites USA Inc. (Chatsworth, CA, US) is exhibiting powder-metallurgy-based aluminum metal-matrix composites (Al MMCs), a family of advanced materials used for demanding aerostructural applications in civilian and defense platforms. DWA-USA converts blended aluminum and silicon carbide (SiC) ceramic powders into vacuum hot-pressed (VHP) billets, which are processed into a variety of shapes and forms using conventional extrusion, forging and rolling. VHP billets range up to 900 lb, so large-scale semi-finished raw materials and finished parts can be produced to meet almost any customer requirement. The primary attributes of DWA-USA Al MMCs are their high isotropic strength- and stiffness-to-weight, fatigue resistance, durability and damage tolerance. The typical gain in yield strength compared to conventional 2000 and 6000 series aluminum alloys is 25-50%, depending on the level of SiC particle reinforcement. Al MMCs reportedly can match the stiffness of titanium while maintaining the density of conventional aluminum. Estimated weight savings for stiffness-critical designs range from 20% to more than 50% compared to aluminum, titanium and steel. DWA-USA says Al MMCs offer a high level of “fit, form and function” in the manufacturing environment compared to other composite materials because normal metalworking and finishing practices are used with little or no modification. Machining of complex geometries with demanding dimensional tolerances are easily accomplished using diamond (PCD) tooling. Chemical milling is superior to conventional aluminum given the ultra-fine microstructure of Al MMCs. The surface treatments commonly used for aluminum alloys can be applied to Al MMCs as well. The fatigue resistance of DWA-USA’s 2009/SiC/15p Al MMC is twice that of AA2024 and AA7075. This has led to it being a material of choice for multiple critical rotating parts on helicopters, providing significant weight savings compared to previously deployed titanium components. Most recently, 6092/SiC/25p Al MMC has been introduced as lightweight bearing liners for helicopter gearboxes, replacing heavier steel parts. Booth Y51.
DWA-USA will present its Al MMC capabilities at the CAMX 2018 Presentation Theater on Oct. 16 at 11:00 a.m.
Designers envision aircraft components that do more than bear structural loads, but must first confront great complexities to actualize greater functional efficiency.
Hand layup has a long history in aerospace composites fabrication, but it's not well suited for automotive composites manufacturing, where volumes are much higher. But the discrete placement of fiber reinforcements still has value. Research is pointing toward automated hand layup that might help this process bridge the aerospace-to-automotive divide.
BMW AG's Dingolfing, Germany, auto manufacturing facility is well known for churning out a variety of car models and types, and the 7 Series is among them, famous for its steel/aluminum/composites construction. Does this car represent the optimum of composites use in vehiicles? This plant tour of the Dingolfing plant looks at how composites on the 7 Series come together.