@techreport{oai:jaxa.repo.nii.ac.jp:00041080,
 author = {村松, 祐治 and 檀, 武弘 and Muramatsu, Yuji and Dan, Takehiro},
 month = {Oct},
 note = {比重差、熱対流の影響の少ない微小重力下での溶融･凝固により、セラミック粒子が微細で、かつ均一に分散した高性能な分散合金を作製するための研究を行った。まず、地上においてこの方法で作製するための検討を行った。実験には高温加圧型電気炉(LIF)を用いた。第1次材料実験(FMPT)における温度プロファイルと試料(Ni-Mo-Cr-TiC合金)の実験後のミクロ組織の変化を示した。FMPT試料のミクロ組織は地上実験試料のそれに比べて均一であった。また、両試料の硬度を比較した結果、地上実験試料はFMPT試料より硬度が低く、試料全体にわたって硬度にばらつきが見られた。このことは、FMPT試料がより均質であり、TiC粒子が微細かつ均一に分布していることを示している。FMPT試料で均一な分散が得られるのは微小重力の効果によるものと考えられる。地上実験試料には、マクロな分離とともに、ミクロ組織の粗大化が観察された。マクロな分離は熱対流と、泡の運動による融液内の擾乱によるものと思われる。また、ミクロ組織の粗大化は熱対流やストークス運動などによるTiC粒子のオストワルド成長または合体の促進によるものと考えられる。, Production of high performance dispersed alloy with finely and homogeneously dispersed ceramic particles was studied by melting and solidification under microgravity giving little influence from difference of gravity and thermal convection. First, this production method was tested on ground surface. Large Isothermal Furnace (LIF) was used in experiment. The temperature profile and microstructure change of sample (Ni-Mo-Cr-TiC alloy) after the experiment in First Material Processing Test (FMPT) were presented. Microstructures of FMPT samples were homogeneous compared to samples produced in ground surface experiment. Further, it was found out from observation of hardness for both samples that hardness of samples produced in ground surface experiment was lower than hardness of FMPT samples, and variation of hardness extended over whole samples. This results indicates that FMPT samples is more homogeneous than samples produced in ground surface experiment, and TiC particles distribute finely and homogeneously. It is guessed that effect of microgravity caused homogeneous dispersion in FMPT samples. Microstructure coarsening was observed in samples produced in ground surface experiment as well as macroseparation. It is considered that cause of macroseparation is thermal convection and disturbance in melted solution generated by bubble motion. Moreover, it is estimated that microstructure coarsening is caused by promotion of Ostwald growth or integration of TiC particles by thermal convection, Stokes motion etc., 資料番号: AA0004116006, レポート番号: NASDA-TMR-940002 V.2},
 title = {粒子分散合金の溶融･凝固},
 year = {1994}
}