Influence of process parameters during pulsed Nd:YAG laser cutting of nickel-base superalloys

Although CO2 lasers have been widely employed for commercial sheet metal cutting operations, increased recognition of the processing benefits afforded by pulsed Nd:YAG lasers has recently fuelled interest in the latter. Pulsed Nd:YAG laser cutting differs from conventional continuous wave laser cutting as it involves overlapping of a series of individual spots generated by each pulse. In this paper, a typical cutting regime for pulsed Nd:YAG laser cutting of 1 mm thick Hastelloy-X sheet has been constructed and explained in terms of extent of spot overlap. The characteristics of single holes drilled employing the same process parameters as those employed for cutting were investigated and correlated with the obtained processing regime. Additionally, the influence of key process parameters like pulse duration on the shift in the constructed processing regime was investigated. Cut quality attributes like kerf width, cut edge kerf profile and surface roughness were also studied and their dependence on process parameters has been discussed.