Effect of total applied energy density on the densification of copper-titanium slabs produced by a DMLF process. http://dx.doi.org/10.1016/j.jmatprotec.2007.08.079

Abstract

The effect of process parameters (laser scan step, scan speed and furnace initial temperature) on the densification degree of copper-titanium single layer slabs produced by a DMLF process is presented here. For each parameter, varied at three levels, specimens were made. An increasing powder densification degree for increasing initial temperature and decreasing scan step and speed was found, when performed at ~ 63 mTorr of oxygen partial pressure in an argon rich atmosphere. However, decrease in densification at large energy densities (~50 J/mm3) occurred. Total applied energy density and powder densification results were fitted to an exponential asymptotic curve using least square error criterion. Reduction in densification at a high energy density plus observation of the asymptotic behavior of the fitted model, are likely because the oxidation of the material inhibits sintering/partial melting of the powder.