Will power through a tungsten electrode discharge is highly concentrated in asmall (? 0.2-2.0mm) range in an instant (shortest 0.001s) the welding wireand base metal melted together. Due to arc time very short, and through microcomputer digital output, and precise control current (minimum 2A), so can precise given will wire and mother material melting of heat, not has extra of energy passed to welding points around; while welding fill interval time reached has welding fill time of dozens of even hundreds of times times, so imitation laser melt covered machine can do on workers mold not deformation, and not bite side, not fever of perfect repair!