Patent ID: 7419632

Claim:
A process for producing a three-dimensional object by layer-wise solidification of a pulverulent material by sintering of the material at points corresponding to the cross-section of the object by means of the action of radiation energy, the process comprising the steps of: applying a layer of the pulverulent material to a substrate or a previously sintered layer; pre-heating the pulverulent material to a working temperature (T A ) below the temperature at which the powder is sintered; sintering of the material at the points corresponding to the cross-section of the object in the layer; and repeating the steps of applying a layer, pre-heating and sintering until the object is completed; wherein, during said process for producing a three-dimensional object, the specific thermal capacity C P (T) of the pulverulent material is established on an applied powder layer before at least one sintering step by determining the quantity of heat taken up per temperature interval (dQ/dT) for at least two temperature intervals, and wherein the process includes controlled heating of an applied powder layer for determining the quantity of heat (Q) taken up by the powder per temperature interval for at least two temperature intervals.