OCT 2018


Issue link:

Contents of this Issue


Page 43 of 83

OCTOBER 2018 42 CompositesWorld Aluminum metal-matrix composites DWA Aluminum Composites USA Inc. (Chatsworth, CA, US) is exhib- iting powder-metallurgy-based aluminum metal-matrix composites (Al MMCs), a family of advanced materials used for demanding aero- structural 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 manufac- turing 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 said to be 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. Reusable vacuum bagging materials Smartech (Charlotte, NC, US) is introducing Steinbach's reusable vacuum bagging materials. The materials are said to pair high elongation with tear resistance to make vacuum forming and infusion processes easier and more cost-efficient. Steinbach offers a variety of reusable silicone vacuum bag materials in sheet form or as a two-sided, sealed bag. Booth M53. Complete workstation solutions for analysis of components and composite materials ● Tension ● Compression ● Shear ● Peel ● Fracture toughness 215 675 7100 Full range of grips to help you meet your ISO, ASTM and other standards SHOW PREVIEW

Articles in this issue

Links on this page

Archives of this issue

view archives of CompositesWorld - OCT 2018