The theoretical capacity of silicon-based anode materials is more than 10 times higher than the capacity of graphite, so silicon can be used as an alternative to graphite anode materials. However, silicon has a much higher contraction and expansion rate due to lithiation of the anode material during the charge and discharge processes, compared to graphite anode materials, resulting in the pulverization of silicon particles during repeated charge and discharge. To compensate for the above issues, there is a growing interest in SiOx materials with a silica or carbon coating to minimize the expansion of the silicon. In this study, spherical silica (SiO2) was synthesized using TEOS as a starting material for the fabrication of such SiOx through heating in a reduction atmosphere. SiOx powder was produced by adding PVA as a carbon source and inducing the reduction of silica by the carbothermal reduction method. The ratio of TEOS to distilled water, the stirring time, and the amount of PVA added were adjusted to induce size and morphology, resulting in uniform nanosized spherical silica particles. For the reduction of the spherical monodisperse silica particles, a nitrogen gas atmosphere mixed with 5 % hydrogen was applied, and oxygen atoms in the silica were selectively removed by the carbothermal reduction method. The produced SiOx powder was characterized by FE-SEM to examine the morphology and size changes of the particles, and XPS and FT-IR were used to examine the x value (O/Si ratio) of the synthesized SiOx.

The purpose of this study is to improve the mechanical properties and develop manufacturing technology through self-soluble alloy powder flame spray coating on the surface of a run-out table roller for hot rolling. The roller surface of the run-out table should maintain high hardness at high temperatures and possess high wear, corrosion, and heat resistances. In addition, sufficient bonding strength between the thermal spray coating layer and base material, which would prevent the peel-off of the coating layer, is also an important factor. In this study, the most suitable powder and process for roll manufacturing technology are determined through the initial selection of commercial alloy powder for roll manufacturing, hardness, component analysis, and bond strength analysis of the powder and thermal spray coating layer according to the powder.

Titanium is the ninth most abundant element in the Earth’s crust and is the fourth most abundant structural metal after aluminum, iron, and magnesium. It exhibits a higher specific strength than steel along with an excellent corrosion resistance, highlighting the promising potential of titanium as a structural metal. However, titanium is difficult to extract from its ore and is classified as a rare metal, despite its abundance. Therefore, the production of titanium is exceedingly low compared to that of common metals. Titanium is conventionally produced as a sponge by the Kroll process. For powder metallurgy (PM), hydrogenation-dehydrogenation (HDH) of the titanium sponge or gas atomization of the titanium bulk is required. Therefore, numerous studies have been conducted on smelting, which replaces the Kroll process and produces powder that can be used directly for PM. In this review, the Kroll process and new smelting technologies of titanium for PM, such as metallothermic, electrolytic, and hydrogen reduction of TiCl4 and TiO2 are discussed.

In this study, Ti powder was fabricated from Ti scrap by the Hydrogenation-Dehydrogenation (HDH)method. Hydrogenation reactions of Ti scrap occurred at near 450oC with a sudden increase in the reactiontemperature and the decreasing pressure of hydrogen gas during the hydrogenation process in the furnace. Thedehydrogenation process was also carried out at 750oC for 2hrs in a vacuum of 10-4torr. After the HDHprocess, a deoxidation treatment was carried out with the Ca(purity: 99.5) at 700oC for 2hrs in the vacuumsystem. It was found that the oxidation content of Ti powder that was deoxidized with Ca showed noticeablylower values, compared to the content obtained by HDH process. In order to fabricate Ti compacts, Ti powderwas sintered at 1100~1400oC for 2hrs under a vacuum of 10-4torr. The relative density of compact was 94.9%at 1300oC. After sintering, all of the Ti compacts showed brittle fracture behavior, which occurred in an elasticrange with short plastic yielding up to a peak stress.

알루미늄 분말야금부품은 철계 분말부품에 비해 가볍고 알루미늄 주조부품에 비해 우수한 기계적 물성을 갖는다. 단, 상대적으로 비싼 가격이 이 부품의 응용을 제약하는 장벽이었으나 최근의 환경과 에너지 문제에 대한 세계적인 관심은 이를 극복할 수 있는 계기를 제공하고 있다. 선진국은 이미 일본을 중심으로 1990년대부터 알루미늄 분말부품에 대한 기술개발을 진행하였고 현재는 다양한 상용 부품을 판매하고 있으며 조만간 그 판매량이 크게 증가할 것으로 예상된다.

Powder forging has progressed in three decades through the stages of incubation, growth, and maturity, now accounting for 8% of the 5 B global PM market. In this presentation, a history of the technical development of powder forging will be recounted, from early failed attempts and misconceptions, through seminal academic and industrial research, to technical and commercial success. Discussion covers the contributions of government and industrial funding, fundamental knowledge development, and industrial champions for successful implementation. The focus is on lessons learned that may be beneficial to the transition of other technologies for the powder metallurgy industry.

In the viewpoint of engineering, materials problem is a key problem, which determines whether the exploitation of fusion energy will be success. The most important class of fusion materials is plasma-facing materials (PFM). W, as high Z high melting-point metal is one of the most important candidate materials due to its high plasma erosion resistance. Improving the ductility of W and W based alloy, lowering its ductile-brittleness transition temperature for meeting the requirements of fusion application is an important task. In this paper, severalpowder meatllurgy methods of fabricating W and W based materials are being investigated.

Filling of the tool die directly influences dimensional tolerances and density variation. To minimize the variations in filling, both within different sections of the cavity and from part to part, are of great importance for produce high quality P/M parts. Filling of the tool die is also one of the limiting factors in the productivity in powder pressing. By using aeration filling in combination with bonded powder mixes, both weight scatter and productivity can be improved. In this presentation results are presented showing the benefit of using aeration filling for different types of powders

티타늄 및 티타늄합금은 강도/밀도 비가 높고, 내열성, 내부식성, 피로강도가 높기 때문에 지금까지 항공, 우주, 해양 및 화학 장치용 소재로서 많이 사용되어 왔다. 최근, 자동차 산업과 레저용 제품 등의 성능과 효율향상을 위해 항공ㆍ우주 산업이나 특수화학장치 산업에 한정되어 사용되고 있던 티타늄소재를, 이들 산업으로 확대하여 응용하고 있다. (중략)

통상적인 금속분말의 성형은 분말야금 공정으로 이루어지기 때문에 복잡한 형상의 부품을 구현하는 데는 제약이 있다. 하지만, 1970년대 후반 이래 새로운 금속분말의 성형기술로 크게 각광을 받으며 연구되고 있는 금속분말사출성형(Metal Powder Injection Molding, MIM) 기술을 이용하면 다양한 형태의 부품을 성형할 수 있다 최근에는 이러한 MIM 기술을 이용하여 다양한 산업분야에 응용될 수 있는 마이크로 부품을 제조하고자 하는 연구개발

CAE technology is an integrated tool including all aspects such as powder, binder system, mixing, injection molding, debinding and sintering. Therefore, CAE technology is considered as one of core technologies for PIM industry in the future. Recently many researchers are developing not only CAE software itself but also application procedures of CAE software. In this study, the applications for CAE technology in PIM industry are presented including feedstock mixing effect, several cases of troubleshooting and optimization procedure.