A Technological Approach for Selective Laser Sintering

Abstract

Two of the key factors in the densification of powders properties in sintering processes — the green body density and green body strength — are studied with the purpose of giving appropriate empirical modeling of the laser sintering of uncoated metal powders. Some proposals for the characterisation of technological properties of powders for selective laser sintering of uncoated powders are discussed in this framework for establishing possible standards for the development of new or improved powders. Methods for the production of metal powders are also considered, with a brief discussion of possible benefits or limitations for this specific application. In the case of mechanical forming at low external pressures, some equations are discussed, linking the variables green body density, green strength and applied pressure. Experimental results for powders of iron, nickel and copper allow to estimate the relevant parameters of the empirical equations. The same parameters are proposed for simple modeling that could be helpful in the selection of powders for the process.