鋳造工学
Online ISSN : 2185-5374
Print ISSN : 1342-0429
ISSN-L : 1342-0429
83 巻, 10 号
選択された号の論文の5件中1~5を表示しています
研究論文
  • 小松 芳成, 後藤 正治, 麻生 節夫
    2011 年 83 巻 10 号 p. 553-560
    発行日: 2011/10/25
    公開日: 2016/01/01
    ジャーナル フリー
      Slurry erosion experiments were conducted focusing on the sand grain concentration of silica sand in slurry, composition forms and mechanical properties of materials, and surface roughness and surface state of the wear surface after slurry erosion test using as sample materials, the aluminum alloys of the Al-Si alloy, which is a dispersion hardening material, and Al-Mg alloy, which is a solution hardening material, for which different hardening methods are applied. The erosion form changed with changes in the concentration of the sand grains in the slurry, and changed to one in which cutting wear increased as the sand particle concentration increased. As for slurry erosion phenomenon, the mass decreasing rate was found to change depending on the compressive-strength of the material, but it depends on material composition when the compressive-strength is the same. Excellent slurry erosion resistant characteristics were obtained with the solution hardening type alloys below their solid solubility limit for erosion statuses of both impingement wear and cutting wear. The wear surface was smooth with less irregularities than other materials. Moreover, roughness of the wear surface after the slurry erosion decreased the smaller was the mass decrease rate, resulting in the smooth surface with less irregularities. The slurry erosion mechanisms for each sample were also discussed based on these experimental results.
  • 梅村 崇, 中村 満
    2011 年 83 巻 10 号 p. 561-568
    発行日: 2011/10/25
    公開日: 2016/01/01
    ジャーナル フリー
      High efficiency machining methods are required for compacted vermicular graphite cast iron (FCV) to reduce production costs. For this reason, we have been conducting basic research on cutting tools for realizing high efficiency machining of FCV.
      In this study, tests were carried out on reactions between cast iron and various tools at high temperature (1403K) at which the state of the tool cutting edge in high speed machining can be reproduced. Three types of cast iron were used as samples; FCV, gray cast iron (FC), and ductile cast iron (FCD). The tools used were Ti(C, N)-Al2O33 coated CVDcemented carbide tool (CVD), Al2O3-Ti(C, N) ceramics tool (CER), and TiC binder cBN tool (cBN). TiC and Al2O3 sintered compact was also tested. Analysis was carried out by line analysis of the interface by EDS, changes in the microstructure near the interface, diffusion layer thickness, and reaction products.
      As a result, it was found that the TiN + Ti(C, N) layer of CVD, Ti(C, N) of CER, cBN particle and TIC binder of cBN reacted with Fe in cast iron. CVD was the thinnest Fe diffusion layer, and cBN was the thickest layer in each cast iron. The Al2O3 layer of CVD, Al2O3 of CER, and Al2O3 sintered compact did not react with Fe. Mg in FCV and FCD condensed on the interface of the {TiN + Ti (C, N)} / Al2O3 layers in CVD as well as on CER and Al2O3 sintered compact. It did not condense on Ti (C, N) sintered compact, and is thought to condense selectively on Al2O3.
      The results of this study suggest that, to realize high efficiency machining of FCV, there is a need to review the tool material from the following viewpoints based on the design of available Al2O3 coated CVD cemented carbides; (1) Higher hardness and thicker Al2O3 layer on the substrate, (2) Better reaction resistance of the Al2O3 layer or to coat the other layers to protect the Al2O3 layer against Mg reaction, (3) Higher thermal conductivity of the substrate to reduce rise in cutting edge temperature.
技術論文
  • 恵良 秀則, 髙瀬 剛二, 細田 恭弘, 大坪 文隆
    2011 年 83 巻 10 号 p. 569-573
    発行日: 2011/10/25
    公開日: 2016/01/01
    ジャーナル フリー
      The viscosity of molten metal is an important factor for calculating flow lines. The aim of this study was to obtain the viscosity of non-combustible magnesium alloy using the theoretically established Hagen-Poiseuille's law. Three kinds of metals; pure aluminum (Al), Al-Si alloy (AC4C), and non-combustible magnesium alloy (Mg-9mass%Al-1mass%Zn-2mass%Ca (were used to measure viscosity. The pressure difference between both ends of the tube was calculated by the hydrostatic stability of gravity (HSG method) as well as by the measured pressure (MP method). The viscosity was obtained from Hagen-Poiseuille's equation. The velocity of the metals when pumped into the silica tube was constant. Therefore, flow was steady in the tube. The viscosity calculated using the MP method was relatively high compared with the HSG method, and consequently showed higher accuracy. This indicates that the MP method provides more reliable viscosity values for non-combustible magnesium alloys.
技術報告
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