プラズマジェットによる岩石類の溶断 (第2報)
セメントモルタルの場合 (2)
1969 年 85 巻 970 号 p. 73-76
詳細
1969 年 85 巻 970 号 p. 73-76
The thermal cutting is thought to be more favorable to rock-like materials than to metals, since, generally, their thermal conductivities are lowerer than those of metals.
Results obtained in case of the cement mortar, as an example of such materials, are as follows.
(1) The depth of cut in this case becomes two or three times greater as compared with the case of cast iron.
(2) The finer the aggregate (silica sand) in the cement mortar is, the greater the depth of cut may be.
(3) The depth of cut increases as the mixing ratio of fine aggregate to cement becomes larger.
The above-mentioned phenomena may be due to the secondary melting action of the dross, because the heat flow from the dross to the cement mortar is little owing to the low thermal conductivity of the mortar. Furthermore, these phenomena are also due to the reduction of heat quantity required to melt the cement mortar by increasing SiO2 component in the molten cement mortar and to the scratching action of the separated fine aggegate.
