Development of Techniques for Laser Additive Manufacturing Mold in Metal Injection Molding (Mim) Using Fe-Based Metallic Glass Powder (Iv)

This project aims at establishing a novel technique for mass-producing Fe-based metallic glass powder (Fe-MGP) and developing its laser additive manufacturing (LAM) technique for making metal injection molding (MIM) molds with conformal-cooling channels (CCCs). Metallic glass has high hardness, wear resistance and corrosion resistance, which can solve the problem of insufficient life-span of current MIM molds while the high cooling efficiency of CCCs is one of the core techs to promote MIM to produce large-size components. In the past three years, the proposing team has successfully developed a recipe of Fe-MG that increases fracture toughness from 4 to 12 MPa√m while maintaining hardness. At the same time, we used the mold steel powder to manufacture two MIM mold inserts, with CCCs, through LAM. The feasibility and excellent cooling performance of these MIM molds were demonstrated through their employments for producing inline commercial MIM components. Meanwhile, the technique of mold flow analysis was also introduced for parameter adjustment during the MIM injection molding process. Other relevant technologies developed include: 1) an innovative ultrasonic grinding technology in liquid, which can polish the Fe-MG mold to a mirror level, surface roughness of Ra = 17 nm；2) a rapid simulation method, that can fast evaluate deformation and residual stresses in the LAM-fabricated mold. This scheme can save, at least, a 50% cost in trial-and-error time and material usage；3) a new digital image correction technology, that can process two-dimenstional deformation and residual stress; and, 4) an innovative property measurement machine, which can simultaneously measure a liquid's surface tension, viscosity and density. In addition, during the past three years, we have published 22 papers, filed 2 patent and conducted 12 industry-academia research projects, with a total amount of 5.85 million.Based on the aforementioned accomplishments, the following three tasks are set for this 4th year’s proposal. (1) Complete the process parameter development for mass producing Fe-MGPs and its technology-transfer course. (2) Realize a new CCC-based MIM mold inserts for manufacturing a key connector. (3) Finish a CCC-based, LAM-fabricated mold insert using our Fe-MGPs and the mold's follow-up surface polishing. Task 1 is to cooperate with a local metal power manufacturer to enable the mass production of our developed Fe-MGPs. Task 2 aims to solve an existing, unstable process problem that keeps bothering a local company in MIMing a key connector. The artificial intelligence models will also be established for adjusting both the injection and sintering process parameters that can avoid the uncertainties relying on engineers’ personal experiences. Task 3 is to realize a LAM-manufactured MIM mold insert, fabricated using the new Fe-MGPs, machined by a self-developed ultrasonic vibration-assisted electrical discharge machining tech.Accordingly, this year’s objective is hereby set as the development of the self-generated MIM’s key technologies including mass production of Fe-MGPs, manufacturing of LAM-based MIM mold insert, and parameter adjusting methods for injection molding and sintering to achieve the ultimate goals of (1) acceleration of mold production and reduction production cost, (2) enhancement of mold life-span, and (3) technology transfer of mass-producible method of Fe-MGPs.