Weldingisafabricationprocessthatjoinsmaterials,usuallymetalsorthermoplastics.Themainideaistobondthesurfacestogetherbyliquefyingthematerialsurfacesandthereafterallowingtheliquidtosolidify.Attheendofthisprocessthetwopiecesofmaterialhavebecomeonecontinuousso (共 1406 字) [阅读本文] >>