Active investigation continues on various alloys used to replace lead for soldering in electronics components. Use of lead has dropped since the Restriction of Hazardous Substances Directive took effect in July, 2006. Historically, interconnections in electronic components have been made using tin/lead solder formulations. Those materials melt at 183C, while the thermoset and thermoplastics used in electronics have temperature limits up to 235C. The glass transition temperature of FR-4, a common PCB material, is between 140-175C. The resin softens as temperatures rise. New lead-free alternates such as SAC become liquid at 217C. Other lead-free solders have even higher melting points, causing failures of laminates and thermoplastics. Materials suppliers are struggling to adapt, says James Hall of ITM Consulting, who gave an interesting overview of the issue during a conference session at National Manufacturing Week in Rosemont, IL. “Just increasing cross-linking in the modified epoxies used in laminates is not the way to go,” he says. Cross-linking increases the brittleness of the laminates, creating problems when the boards are drilled. Specialty thermoplastics, such as modified nylons, are also experiencing problems because of the high solder temperatures. Explorations continue on new plastics as well as new solder formulations, including significant use of dopants such as nickel and germanium that provide specific property enhancements for various reasons.
Several of the new and noteworthy 3D printers in this slideshow are breaking some boundaries in build volume, new metals printing techniques, or working with high-profile development partners to ensure very high-quality parts and controls.
United Launch Alliance will fly 3D-printed flight hardeware parts on its rockets starting next year with the Atlas V. The company's Vulcan next-gen launch vehicle will have more than 100 production parts made with 3D printing. The main driver? Parts consolidation and 57% lower production costs.
A new report from the National Institute of Standards and Technology (NIST) makes a start on developing control schemes, process measurements, and modeling and simulation methods for powder bed fusion additive manufacturing.
Although bio-based polymers face challenges from petroleum-based polymers, in certain markets they can displace the petro-based incumbents. Here are six new bio-based and renewable plastics for a variety of applications.
BASF has developed tools and initiatives to help engineers use more of its renewable materials in their designs, more effectively, as well as to build parts using them with more predictable performance.
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