Almalki A., Rajhi A., Noor H., Kundu A., Coulter J.P.
Lehigh University, US
Keywords: bulk metallic glass, microinjection molding, MoldFlow, tooling lifetime
The lifetime of a commercially available zirconium based bulk metallic glass (BMG) for microinjection molding (μIM) was investigated in this research. The primary objective was to understand the effect of the molding conditions on the BMG tooling. The composition of the Zr- based BMG alloy was Zr67 Cu10.6 Ni9.8 Ti8.8 Be3.8. A focused ion beam (FIB) milling process was utilized to fabricate the microfeatures. The microfeatures were circular cross- section, 5 μm in diameter with diameter to depth aspect ratio of 1, and 10 μm edge-to-edge. The optimal molding processing parameters were initially obtained using MoldFlow simulation. The durability of the BMG mold was investigated by molding parts of thermoplastic polyurethane (TPU) material. The BMG insert was successfully utilized 1000 cycles of μIM. It was mechanically stable during these experiments. Even after potential crystallization, no sign of any crack initiation was observed in any part of the BMG mold insert. The replication quality degraded with increasing molding cycles. However, the replication quality improved when the cavities were cleaned on heating to an elevated temperature after 750 cycles of injection molding.
Journal: TechConnect Briefs
Volume: TechConnect Briefs 2021
Published: October 18, 2021
Pages: 13 - 17
Industry sector: Advanced Materials & Manufacturing
Topics: 3D Printing, Advanced Manufacturing
ISBN: 978-0-578-99550-2