A Xyloy alloy injection-molded part (left) provides the benefit of metal properties coupled with the ease of processing typically associated with plastic (right).
Emphasizing that metal injection molding (MIM) is not required, Cool Polymers Inc. has unveiled a lightweight metal alloy capable of being processed using standard injection molding equipment and tools designed for plastic. The injection-moldable Xyloy alloy affords OEMs the opportunity to reap the benefits of a material that combines the desirable properties of metal with the processing ease of plastic.
“The MIM process tends to be limited in part size—not conceptually so much, but practically speaking—because of cost and tolerances, and things like that,” says Jim Miller, Xyloy product manager. “These parts can be more in the range of what is typically molded with plastic injection molding, which would be parts ranging anywhere from a few grams in weight up to a few pounds.” Molded into 3-D, net-shape parts, Xyloy yields nonporous products that Cool Polymers maintains are stronger than die-cast metal parts. Properties include those typically associated with metals, including stiffness and thermal and electrical conductivity. Xyloy exhibits an ultimate tensile strength of 325 MPa, a yield strength of 250 MPa, an elongation at break of 2%, a modulus of elasticity of 90 GPa, and thermal conductivity of 110 W/mK. Mold shrinkage amounts to less than 0.5%.
Parts molded employing Xyloy do not require secondary operations and experience cycle times comparable to those of plastic injection molding, according to the manufacturer. In addition, finished parts can be textured or painted and accept plating and powder coatings.
“The conventional wisdom with plastic is that there is design freedom, and I think that this is bringing those features to metal parts,” Miller says.
Cool Polymers Inc., Warwick, RI