Control of defects during laser surface alloying

摘要

Laser surface alloying is a new and promisingtechnique for generating surface alloys having a wide range offavourable properties. The process involves altering the surfaces ofinexpensive substrates by adding small quantities of alloyingelements to a pool of molten metal produced by local meltingusing the intense heat of a laser. Certain defects such as cracks,porosity, surface roughness, compositional inhomogeneity, andexcessive dilution have been observed during laser alloying(pulsed Nd:YAG laser) with chromium on mild steel, and withmolybdenum and Ni-Mo on stainless steel. Specific deteriorationin surface properties has been observed and discussed and thetechniques utilised to control such defects have been outlined.