Graduate School of Engineering
Department of Metallurgy

Research Topics

Casting CAE and CAO

Casting CAE(Computer Aided Engineering) System named "Adcanced Stefan(AdStefan)" was commercialized under the support of about 40 Japanese manufacturing companies in 1999. The AdStefan consists of pre-processor, solvers, post-processor and materials database. With AdStefan, casting engineers can simulate solidification, mold filling and thermal deformation of complex shaped castings very quickly. The AdStefan can run on UNIX including Linux and MS Windows systems. Our original defects prediction method called "NIYAMA criterion" is favored by casting engineers all over the world because of its ease of use, versatility and robustness. The NIYAMA criterion is a de facto standard, now. Over 140 packages are utilizing not only in Japan but also in foreign countries, i.e. U.S.A., Korean, Taiwan, Indonesia, Thai, etc.

Fluidity of Aluminum and Magnesium Alloy for Casting

There are a lot of casting products of aluminum alloys or magnesium alloys around our life. To fabricate sound castings, fluidity is one of the most important parameter, in particular, thin products such as a casing of portable personal computer. Fluidity of the alloys is affected by their thermal properties including a liquidus point and heat of fusion. These properties are can be calculate with the thermodynamics database, nowadays. In other words, we can predict fluidity of a lot of alloys without enormous experimental studies. In the future, developed materials with high fluidity will be used in order to fabricate thinner and thinner products.

Solidification and Deformation of Lead Free Solder Alloys

Development of lead free solder alloys is fundamental to prevent environmental pollution by lead because of industrial discharge of electronics products that contain tons of lead solder as a whole. At this moment, several candidates for the lead free alloys are known. however, these alloys have very poor process characteristics that make it difficult to prevent shrinkage and lift-off defects. Generation of these defects are strongly depends on a solidification feature of the lead free solder alloy. Solidification simulation techniques with thermodynamics calculation software are investigating for optimization of soldering process parameters.

Salt Core

Manufacturing of metal products which have complicated inside shape such as a closed deck cylinder block by die-casting method is difficult because there are no suitable materials for cores. Water soluble salt is believed that it is a candidate for new core material since salt cores can be removed immediately from products and a recycle is possible. One of the most serious problems of use of salt core is its brittle character and fabricating process of salt core itself. In recent two years, the problem about strength of salt cores has been studied and solved. Fabricating salt cores, die-casting with salt cores, dissolving cores from products and recycling salts are investigating in order to develop the new practical process for manufacturing of complicated shaped products.