Method for producing work pieces having a tailored microstructure

A method for producing a three-dimensional work piece, the method comprising:

• applying a raw material powder onto a carrier,
• selectively irradiating electromagnetic or particle radiation onto the raw material powder applied onto the carrier,
• controlling the applying the raw material powder and the selectively irradiating electromagnetic or particle radiation onto the raw material powder to obtain a combination of crystal growth velocity and temperature gradient associated with a desired microstructure of a work piece made of the raw material powder by an additive layer construction method, wherein controlling the applying the raw material powder and the selectively irradiating electromagnetic or particle radiation onto the raw material powder includes
• setting operating parameters of (i) a source of electromagnetic or particle radiation, (ii) an optical unit adapted to guide and/or process a radiation beam emitted by the source of electromagnetic or particle radiation, and (iii) a powder application device adapted to apply raw material powder onto the carrier to produce an outer shell region of the work piece that has a substantially polycrystalline globulitic microstructure, and
• setting operating parameters of (i) the source of electromagnetic or particle radiation, (ii) the optical unit, and (iii) the powder application device to produce an inner core region of the work piece that has a substantially single crystalline or directionally/dendritically solidified microstructure.