For the new practical application and the expansion of ferrous sintered components, the improvement of mechanical properties of sintered steels and the advancement of the near net shape compacting technology are important. In this paper, the following two solution examples for these subjects are mentioned. One is an improvement of mechanical properties of the sintered steels by the addition of carbon and/or hard particles to the sintered steel with high copper contents. The other is an analysis of micro crack formation during a practical powder compaction process on the basis of the experiment and the FEM simulation.

This products are pure iron Soft Magnetic Composite (SMC) reactor cores for voltage boosting and rectification inside of inverter of photovoltaic system.

The hardness of pure iron SMC itself is soft, so in compaction process, pure iron powders tend to plastic flow and destroy insulation films. Then, the original characteristics are unavailable because of the drastic increase in eddy current loss. So, we developed new lubricant for SMC which can prevent from plastic flow at the sliding surface as well as improving the insulation properties.

One of lubricant elements slides between metal powders and dies, protecting the metal particle shapes and preventing from plastic flow. Whereas, one of insulation elements combines with insulation films preferentially and improves insulation properties of sliding surface.

Not only is the specific resistivity of sliding surface and compression surface equivalent, the core loss is maintained low. Finally, with developed lubricant, we achieved the net-shape manufacturing of reactor core without surface finishing and restriction of assembling directions.

Although conventional chemical or thermal recycling techniques are often the most appropriate means of recovering precious and rare metals, biological methods provide an attractive and eco-friendly alternative strategy in which metal ion-reducing microorganisms, Shewanella bacteria are applied to separate and concentrate precious and rare metals from aqueous solutions. We have developed a new biomineralization system to reduce soluble palladium(II), rhodium(III), platinum(IV), and gold(III) into insoluble metal nanoparticles at room temperature within 120 min. Biogenic palladium nanoparticles on the cell surface were found to exhibit better catalytic properties than those of commercial palladium catalysts. When processing the aqua regia leachate of spent automotive catalysts by adjusting its pH, Shewanella bacteria were able to rapidly and selectively collect platinum group metals. We also proposed a new biosorption system to separate soluble indium(III) or dysprosium(III) into microbial cells. We achieved selective adsorption of indium(III) ions in Shewanella bacteria from the leachate of spent liquid crystal displays by adjusting its pH. Our proposed microbial methods enable the rapid and highly efficient recovery of precious and rare metals by using Shewanella bacteria.

The improvement and design of materials for automotive catalyst, especially alumina support is described by the author’s work. Since automobile engine exhaust sometimes becomes a high-temperature gas, the thermal durability of catalytic powders is very important. For this, the improvement in materials design and thermal stabilization is required for all composition of catalysts. The supported noble metals, thermal stable alumina support and zirconia-ceria sub-catalysts must be controlled by the resultant microstructures where each nanoparticles are mixed and rearranged even after harsh heat treatment. For the alumina catalytic support, the phase transition and surface modification are closely related to realize better heat stable materials with nanometer-order particles in size. The anti-sintering stabilization of γ-Al₂O₃ before a transformation is a research target, and is improved by an approach with both elements modification and ceramic sintering technique. The tailored La-modification to alumina support and its processing provides a novel nanostructured and stable catalytic composite support even at elevated temperatures. The wash-coating technique must allow obtaining coatings on most metallic substrate with the required homogeneity. This work also discusses the material parameter controlling the coating of FeCrAl alloy metallic monoliths by using thermal stabilized alumina with lanthanum through focusing on the microstructural development of sintered layer and alumina/alloy interface. The paper describes effect of surface modification especially surface La added on alumina powders in the anti-sintering, and composite formation and coating technology of forming catalytic coat layer.