Processing Liquidmetal® alloys is challenging because it is highly reactive to oxygen in its molten state. Thus, Liquidmetal alloys must be processed quickly and under highly controlled vacuum. To meet these requirements, Liquidmetal Technologies has developed a 3rd Generation Liquidmetal Injection Molding system in cooperation with ENGEL. The machine utilizes ENGEL’s standard plastics injection-molding platform as a foundation with simple bolt-on components. Liquidmetal ingots are loaded into the machine, a cycle occurs, and after a couple minutes, a tree of Liquidmetal parts is extracted. Because Liquidmetal alloys are processed under a vacuum, the final surface finish is fine, lustrous and free of oxidation directly from the mold. The parts can then be processed to simply remove the gates and runners. Current machines are designed for 100 gram shot charges per cycle, leading to the suggested part size of 80 grams.
The innovative single-step Liquidmetal Injection Molding process is high precision, clean, efficient and achieves four things simultaneously:
- Feedstock material is transformed from crystalline to amorphous (solid-liquid)
- The final net-shape part is formed (with minimal shrinkage)
- As-cast surface properties are generated (beautiful as-molded finish rivals polished parts)
- Ultimate strength properties are generated (unsurpassed strength as-molded)
For most customers, the only post-processing step required is to remove the part from the runner, which carries the alloy into the part geometry in the mold. This is in contrast to other processes that require secondary annealing, sintering, coating, polishing, or other steps to achieve the desired strength or appearance.