The University of Tokyo · Engineering
Professor Yongsheng Ren's research lab specializes in advanced materials development, with a primary focus on high-entropy alloys, aluminum alloy purification and refinement, and high-purity silicon crystal growth. The lab investigates innovative processing techniques to enhance material properties, including novel purification methods for aluminum and silicon, and the use of reactive elements like zirconium to remove impurities such as boron. Their work spans from fundamental thermodynamics and kinetics to practical applications in aerospace, electronics, and photovoltaics.
Figures are computed from collected data and may differ slightly.
In recent years, high-entropy alloys (HEAs) have attracted tremendous attention in various fields. With multiple-principal elements and multiple core effects, giving them different organizational structures and unique properties compared with conventional alloys, providing unlimited development potential and bringing promising potential applications for HEAs. After almost 30 years of development, the preparation and research methods of HEAs have greatly expanded, the systems have been optimized,
Aluminum, the most produced non-ferrous metal in the world, is highly regarded for its light weight, high specific strength, and excellent thermal conductivity. With the continuous development of aerospace, precision electronics, photovoltaic semiconductors and other emerging strategic industries, the demand for high-performance aluminum alloys is also booming. The paper discusses recent advances in aluminum alloy melt purification, focusing on the development of conventional purification treatm
Aluminum is the world's largest production of non-ferrous metals, with light weight, high specific strength, excellent electrical and thermal conductivity and other characteristics. With the continuous development of aerospace, precision electronic instruments, photovoltaic semiconductors and other emerging strategic industries, the demand for high-performance materials of aluminum alloys has become increasingly strong. This paper reviews the research progress of aluminum alloy melt refinement t
A novel approach was put forward to remove B from Si by utilizing Zr as an additive during solidification, whereby, using the Si–Cu solvent, bulk Si with large area and low boron content was obtained. The premise of this work is based on the following parameters: (i) the lower liquidus temperature of the Si–Cu system; (ii) the notable density difference between solid Si and liquid Si–Cu; (iii) the low solubility of Cu in solid Si; and (iv) the strong affinity of Zr for B, enhancing boride format
Based on (i) the low liquidus temperature of Si–Cu systems, (ii) low solubility of Cu in solid Si, and (iii) a strong affinity of Zr to B for the enhanced boride formation, a novel method to remove B from Si using Zr as a trapping agent via a Si–Cu solvent was developed in this study. B-bearing polygonal ZrBx precipitations found at the bottom of test samples were confirmed as ZrB2 by electron probe microanalysis. Thermodynamic analysis revealed that the solubility products of ZrB2 in a Si–Cu me
• Heater radiant area affects crystal oxygen concentration and heater power . • Quartz crucible temperature controls crystal oxygen concentration. • Reducing heater height lowers crystal oxygen but raises power. • With the upgraded heater, power decreased by 1.07 kW and average head oxygen concentration decreased by 0.66 ppma. Oxygen is the major impurity in single-crystal silicon rod derived from the growth of large-diameter n-type Czochralski (Cz) silicon, which could exert severe affects on t
Open papers in the app to read, cite, and organize with AI.
