A new process was proposed to fabricate intermetallic compounds reinforced aluminum matrix composite by the reaction between metal powders and molten aluminum. Nickel powders were added gradually onto the surface of molten pure aluminum by stirring. Al₃Ni particles which are smaller than the added nickel powder were in situ formed and dispersed homogeneously in the aluminum. The processing temperature was lower and the stirring time was shorter than those of the conventional vortex method for fabricating non-metal (Al₂O₃, SiC etc) reinforced aluminum matrix composites. The effects of processing variables, such as processing temperature, size of nickel powder, and stirring time, on the formation and dispersion behavior of Al₃Ni were investigated. It was found that the size of Al₃Ni decreased with decreasing processing temperature and stirring time. The process was also applied to Ti, Zr, Cr, Mo, W and Fe powders. Al₃Ti, Al₃Zr, Al₇Cr and Al₁₂Mo were formed and dispersed homogeneously, but the others failed. The size of intermetallic compounds depended considerably on the type of metal powder. The dispersion of intermetallic compounds was affected by the oxidation of metal powders. This process was applicable to JIS AC8A aluminum alloy for forming AC8A-Al₃Ni composite.

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  A technique was developed to insert a ceramic bar into cast iron using a flake graphite cast iron cover without preheating the bar. This technique allows the heat energy of the molten metal to be utilized to produce cast iron products which are added with functions of ceramic materials. Excellent results were obtained by using a method whereby a ceramic bar is covered with a flake graphite cast iron cover and fixed in a sand mold and then molten metal is poured. However, since there are applications whose purposes require the use of spherical graphite cast iron (FCD) instead of flake graphite cast iron (FC), there can be different combinations of molten metal and cover material in practice.
  In this study, experiments were conducted using a number of combinations of molten metal and cover material including combinations that use FCD, which differs in characteristics from FC, for the mo1ten metal, cover material and both, to examine and analyze the effects of each combination on the insert casting.
  From these experiments, a molten metal quantity range was found within which all of the combinations of cover material and molten metal of FC and FCD produced an excellent insert casting result. It was also found that the molten metal quantity (weight) range within which good insert casting result can be obtained with molten metal of FCD was wider than that within which good insert casting results can be obtained with molten metal of FC. It was shown that this was because of the lower rate of increase in the temperature of the ceramic bar due to the higher surface tension and lower thermal conductivity of FCD.

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  Ni-Al intermetallic compounds containing silicon were coated onto a spheroidal graphite cast iron substrate through combustion synthesis. In this paper, effects of silicon addition on coating characteristics, such as constituents, hardness, wear resistance and adhesive strength, were investigated. A differential thermal analysis exhibited that silicon addition to Ni-Al green powder compacts lowered both a combustion and an ignition temperature with an increasing exothermic value. All of the coating layers consisted of multi-constituents with layers along the bonding interface. Al-Si liquid phase generated in the silicon added coating decreased void fraction in coating layers. Synthesized nickel aluminide coating layers had hardness of over 600 HV in the silicon addition up to 9 atomic percent. All of the coating layers showed drastically improved wear resistance compared with that of an FCD substrate. Adhesive strength of coatings was improved by silicon addition to Ni-Al green powder compacts due to thinning of the brittle layer along the bonding interface.

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  An ultrasonically vibrating end surface can retain large amount of liquid, the phenomenon of which has been newly discovered by author's group. Amount of adhering liquid linearly increases with vibration amplitude unless the cavitation occurs. At the same amount of adhering liquid, the droplet appearance becomes flatter to the vibrating end surface with an increase in vibration amplitude. The mechanism which allows large amount of liquid adhesion is discussed by focusing on the distribution of radiation pressure in an adhering droplet. The radiation pressure in a droplet exponentially decreases with distance from the horn end surface. A dynamic balance model regarding an adhering droplet was constructed through taking into consideration of the balance of liquid weight. intrinsic surface tension and radiation pressure. The calculated droplet appearance based on the model is good agreement with the experimentally observed one. With dipping and raising-up of an ultrasonically vibrated horn end to molten magnesium alloy, the maximum adhesion attains at 873 K, at which adhering metal is a semi-solid state approved by temperature measurement. Ultrasonic casting of magnesium alloy, in which the adhering molten or semi-solid metal is compressed by the counter molds, was carried out using a high powered ultrasonic transducer for shaping a thin saucer. Cast products are successfully manufactured without appreciable defects, because long molten metal flow is not necessary in the novel casing process.

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  Feasibility examinations on phase (refraction) contrast X-ray imaging with highly brilliant microbeam were carried out on metallic materials containing crack, slit or second particle by using the branched experimental hutch C of beamline BL24XU, SPring-8.Two kinds of X-ray beam conditions were adopted. One was direct monochrome beam tuned at 15 keV. The other was the refracted X-ray beam which was expanded horizontally by asymmetric reflections for the monochrome beam. Vertical expansion was also obtained by synchronized stage scanning to enlarge the area of observation.
  We examined wedge shape specimens of SUS316 steel with a fatigue crack, 5N-aluminum with slits and nodular iron, respectively. The phase contrast profile of both the fatigue crack in SUS316 and slits fabricated in aluminum was extracted from recorded image by subtracting absorption contrast. The slit-depth was successfully evaluated by the relation of the distance between highlight and dark bands to the incident angle. For nodular iron, the phase contrast profile of the spheroidal graphite was detected together with the absorption contrast.

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