We newly designed and manufactured a new arranging system for a three-dimensional artificial crystal of monosized micro particles. In this system, a robotic micro-manipulator accurately locates the spherical particle onto the lattice point, and subsequently fiber lasers micro-weld the contact points between the neighboring particles. Actually, one- and two-dimensional arrays were constructed using monosized tin particles with the diameter of 400 m. Moreover, due to optimization of the process parameters, we successfully constructed the artificial crystals of simple cubic and diamond structures. In particular, the diamond structure which can represent a large photonic band gap is expected to progress toward a practical photonic crystal device.

The decrease of the distance between particle centers due to the growth of the sinter necks can be explained by the well known two-particle model. Unfortunately this model fails to provide a comprehensive description of the processes for 3D specimens. Furthermore, there is a significant discrepancy between the calculated and the measured shrinkage because particle rearrangements are not considered. Only the recently developed analysis of the particle movements inside of 3D specimens using micro focus computed tomography (μCT), combined with photogrammetric image analysis, can deliver the necessary experimental data to improve existing sintering theories. In this work, μCT analysis was applied to spherical copper powders. Based on photogrammetric image analysis, it is possible to determine the positions of all particle centers for tracking the particles over the entire sintering process and to follow the formation and breaking of the particle bonds. In this paper, we present an in-depth analysis of the obtaine data. In the future, high resolution synchrotron radiation tomography will be utilized to obtain in-situ data and images of higher resolution.

Manufacturing technologies of micro parts were studied in nano grained Al-1.5mass%Mg alloy. During compressive test at 300 , the Al alloy showed stain softening ℃ phenomenon by grain boundary sliding regardless of strain rate. Micro spur gear with ten teeth (height of 200 μm and pitch of 250 μm) was fabricated with sound shape by micro forging. During micro forging, increase of applied stress induced by friction between material and die surface was effectively compensated by decrease of stress by strain softening behavior and as a result, flow stress increased only about 50 MPa more than that in compressive test.

Recently the Marangoni convention is supposed to be an important phenomenon that significantly affects the solidification. For understanding the Marangoni convection mechanism, visualizing the convention phenomenon of molten tin with ultrasonic has been conducted. This paper reports developing a tracer material of micro metal balloon that is used in the molten system. We have succeeded in coating the surface of Shirasu-ballons with nickel by plating process. The obtained metal balloon is spherical and some characterizations were conducted.

Micro-porous nickel (Ni) with an open cell structure was fabricated by powder metallurgy. The pore size of the micro-porous Ni approximated and . For comparison, porous Ni with a macro-porous structure were also prepared by both powder metallurgy (pore size ) and the traditional chemical vapour deposition method (pore size ). The mechanical properties of the micro-and macro-porous Ni samples were evaluated using compressive tests. Results indicate that the micro-porous Ni samples exhibited significantly enhanced mechanical properties, compared to those of the macro-porous Ni samples.

Mono-sized silicon particles were effectively fabricated by a novel way named pulsated orifice ejection method (POEM). The particles are with very narrow particles size distribution and very small standard deviation of mean particle size. There are two different types spherical silicon particles were found. One consists of many grains mainly in random boundaries. The other consists of two or three grains with only twin orientation relationships, even single crystal in cross-section was also found within this type of spherical silicon particles.

High functional micro devices are demanded in a variety of fields. For realising such demands, development of high-precision micro-components installed in the devices are needed. To achieve high-precision in the mold processing of micro-components, the development of mold materials, i.e., the development of WC-Co hardmetal with higher hardness and fracture strength is essential, together with the developments of processing technology of high precision mold and mold-forming technology of high precision micro-components, etc. The role of development of the finer submicro-grained hardmetal in a NEDO national project aiming the integrated development of these all technologies and some results are mainly explained.

New powder compaction process, in which a Bingham semi-solid/fluid mold is utilized, is developed to fabricate micro parts. In the present process, a powder material is filled as slurry in a solid wax mold, dried and compressed. The wax is heated during compaction and becomes semi-solid state, which can acts as a pressurized medium for isostatic compaction. Since the compacted micro parts are very fragile, the mold's temperature is controlled to higher than its melting point during unloading, to avoid breakage of the compacts. To demonstrate effectiveness of this process, some micro compacts of alumina are shown as examples.

A novel production method for porous metal components has been developed by applying powder space holder (PSH) method to metal powder injection molding (MIM) process. The PSH-MIM method has an industrial competitive advantage that is capable of net-shape manufacturing the micro-sized porous metal products with complicated shapes and controlled porosity and pore size. In this study, the small impeller with homogeneous micro-porous structure was manufactured by the PSH-MIM method. The effects of combinations in size and fraction of PMMA particle on dimensional tolerance and variation of sintered porous specimens were investigated. It was concluded that the PSH-MIM method could manufacture commercially microporous metal components with high dimensional accuracy.

In recent years, micro powder injection molding is being explored as an economical fabrication method for microcomponents in microsystems technology (MST). Technical and economic comparison was performed for processes. Molding experiment and simulation during the filling process were performed to evaluate several different geometries and processing conditions. The influence of material parameters and process conditions on mold filling were examined as a function of features size using microchannels as an example. It was found that the heat conductivity and viscosity of feedstock, geometry and mold temperature were the most critical parameters for complete filling of micro features.

The production method of micro sacrificial plastic mold insert metal injection molding, namely process has been proposed to solve specific problems involving the miniaturization of MIM. Two types of sacrificial plastic molds (SP-mold) with fine structures were used: 1) PMMA resist, 2) PMMA mold injected into Ni-electroform, which is a typical LIGA () process. Stainless steel 316L feedstock was injection-molded into the SP-molds with multi-pillar structures. This study focused on the effects of metal particle size and processing conditions on the shrinkage, transcription and surface roughness of sintered parts.

Small powder size is very useful in achieving detailed structures. STS 316 nanopowders with an average diameter of 100 nm and were utilized to produce feedstock. The mixing behavior of the feedstock indicated that the nanoparticle feedstock produced the highest mixing torque at various powder loading compared to the micropowder feedstock. The nanoparticles feedstocks showed that elastic properties are dominant in flow behavior and high viscosity. Conversely the micropowders feedstocks, viscous properties are dominant in flow behavior and less viscosity, nanopowders feedstock perform lower flow activation energy than feedstock with bigger particles.

This study aims to investigate the usage of nano-scale particles in a micro metal injection molding (-MIM) process. Nanoscale particle is effective to improve transcription and surface roughness in small structure. Moreover, the effects of hybrid micro/nano particles, Cu/Cu and SUS/Cu were investigated. Small dumbbell specimens were produced using various feedstocks prepared by changing binder content and fraction of nano-scale Cu particle (0.3 and in particle size). The effects of adding the fraction of nano-scale Cu powder on the melt viscosity of the feedstock, microstructure, density and tensile strength of sintered parts were discussed.

The development of Micro MIM as a new manufacturing process for metallic micro parts made of advanced functional materials has been the subject of considerable research over the last years. This paper addresses important quality aspects on processing of new materials by Micro-MIM. Three examples of new functional materials that can be processed are reviewed in this paper. The first example is two-component-Micro-MIM to obtain multi-functional devices. A micro positioning encoder consisting of a magnetic / non-magnetic material combination is presented. The second issue is series production of the replicate of the smallest human bone in the ear (stapes) from Titanium as an example of medical application. Quality assurance and reproducibility in terms of injection moulding parameters are addressed. In the third part, first results on the processing of the shape memory alloy NiTi by Micro-MIM are presented. Potential applications include biocompatible devices and transportation, for example automotive and aerospace. Processing routes and initial microstructures obtained are discussed.