Metal Injection Molding Technology Research Articles

射出成形 米国ＭＩＭ市場の現況

It is said that there are more than 40 MIM (Metal Injection Molding)-related companies in America. Aiming at the diffusion of MIM, 21 of these companies have formed and are members of an organization called MIMA (Metal Injection Molding Association). MIMA is one of the lower branches of MPIF (Metal Powder Industries Federation). Among MIMA member companies, there are MIM parts producers; powders, binders and feedstock suppliers; and MIM machine, debinding and sintering equipment suppliers. Last year, MIMA sent out a questionnaire to each of its member companies to inquire into the present conditions and future prospects of the MIM business, problems that hinder the diffusion of MIM, measures to be taken in order to achieve diffusion, etc. The results, which were totaled and released to member companies last year in October, indicated that most of the companies believed that a lack of educational campaigns aimed at part designers, who are MIM customers, was impeding MIM diffusion. At present, since it is also believed in Japan that the achievement of diffusion of MIM technology depends on the improvement of the understanding level of part designers, JSPM (Japan Society of Powder and Powder Metallurgy) and JPMA (Japan Powder Metallurgy Association) have begun to take measures aiming at MIM standardization and educational campaigns. We have the impression that the problems confronting MIM are the same around the world. The findings of this survey provide very interesting hints, and we believe that they will be a good reference for the development of MIM technology in our country.

Investigation of core loss in PM micro-motor made using MIM technology

Research has been conducted into the effects of particle size on the core losses of soft magnetic materials. Various types of micro PM BLDC motors, produced with solid hog-out alloy steel, laminated alloy steel and Metal Injection Molding (MIM) alloy steel powders have been studied. The results show that the core loss of micro PM BLDC motors made by the MIM technique is in the acceptable level when compared with the laminated core motor.

P/M high speed steels obtained by metal injection moulding

In this work we compare an AISI M2 high speed steel obtained through conventional P/M technique with another obtained by metal injection moulding (MIM). MIM technology have been developed strongly during last ten years, thanks to it feasibility of making parts of high precision, complicate shape and low cost.

金属射出成形におけるコンパウンドの流動性および加熱脱脂時の変形におよぼす粉末特性の影響

In MIM (Metal Injection Molding) technology, moldability of feedstock and resistivity of compact to debinding deformation are very important to mold highly complex shapes without defects and to maintain close tolerances of final products, respectively.In this paper, the effects of powder characteristics on the flowability of feedstock and the deformation of compact during thermal debinding were studied using 6 kinds of powders. For specific powders, the effect of binder content was also investigated. The flowability of feedstock was estimated by MFR (Melt Flow Rate) at 170°C, while the debinding deformation was determined in bending mode using rectangular bar specimens supported both ends.As expected, spherical powders exhibited much higher flowability of feedstock than irregular powders, showing flowability in proportion to the tap density. For irregular powders, however, there observed no correlation between the folwability of feedstock and the tap density of powder. The flowability of feedstock increased with increasing binder content for both spherical and irregular powders. On the other hand, spherical powders showed much lower resistance to debinding deformation than irregular powders. For both spherical and irregular powders, the resistance to debinding deformation increased with decreasing mean particle size and decreased with increasing binder content.It was concluded the above results that there exists inverse relationship between the flowability of feedstock and the resistance of compact to debinding deformation because they are inversely affected by the same factors i.e. interparticle friction and/or interparticle separation.