Formation of fine alloy layer by using the penetration heat source effect of electron.

将高压电子在穿透过程中深入金属材料，使金属材料熔化的穿透愈合源效应应用于表面改性。利用自行研制的500kV超高压电子束热源对金属进行了表面改性。热喷涂合金粉末（80%Ni 2O%Cr），厚度：0.3 - 0。用500kV电子束（功率0.3 ~ 3kw，束扫描速度0.75 ~ 2mm/s，束径4 ~ 7mm）辐照粘贴在SM400、SK4钢上的6mm材料。粉末和一部分贱金属瞬间从材料内部熔化，从而抑制了溅射和孔隙等内部缺陷。熔透深度为0.4-O的焊珠。获得了8mm高浓度的粉末元素（Ni: - 40%, Cr: -10%）。利用高速摄像机对焊缝成形过程中的熔蚀现象进行了观察。发现合金粉末在母材上的熔化过程每隔几百毫秒重复一次，这一周期性过程抑制了溅射。对仅含13%Ni的焊头进行5%112S04腐蚀试验，结果表明不锈钢（SUS3O4）的腐蚀值与此相似。这意味着通过合理选择粉末的化学成分，可以进一步改善粉末的侵蚀性能。

The penetration heal source effect, that high voltage electrons penetrate deeply into metallic materials melting them during penetration process was applied to surface modification. Surface modification of metals was performed with the 500kV ultra high voltage electron beam heat source which is developing by the authors. Alloy powder for thermal spraying (80%Ni 2O%Cr, thickness : O.3-O.6mm) which was pasted on steels (SM400, SK4) were irradiated by the 500kV electron beam (power0.3-3kW, beam scanning speed : 0.75-2mm/s, beam diameter : 4-7mm) . Powder and a part of base metal were instantaneously melted from inside of materials, resulting suppression of sputtering and internal defects such as porosities. Weld beads having the penetration depth of 0.4-O.8mm with high concentration rate of powder elements (Ni : -4O%, Cr : -10%) were obtained.Nelting phenomena were observed by a high speed video camera during formation process of weld bead. It is found that the melting process of alloy powder on base metal was repeated with few hundreds millisecond intervals and this periodic process suppressed spattering. Result of 5%112S04 erosion test of weld bead containing only 13%Ni showed a similar value for stainless steel (SUS3O4). This means that further improvement of erosion property can be expected by properly selection of chemical composition of powder.