초록 ▼

A laser-sinterable powder product has been prepared having unique properties which allow the powder to be sintered in a selective laser sintering machine to form a sintered part which is near-fully dense. For most purposes, the sintered part is indistinguishable from another part having the same dim

A laser-sinterable powder product has been prepared having unique properties which allow the powder to be sintered in a selective laser sintering machine to form a sintered part which is near-fully dense. For most purposes, the sintered part is indistinguishable from another part having the same dimensions made by isotropically molding the powder. In addition to being freely flowable at a temperature near its softening temperature, a useful powder is disclosed that has a two-tier distribution in which substantially no primary particles have an average diameter greater than 180 .mu.m, provided further that the number average ratio of particles smaller than 53 .mu.m is greater than 80%, the remaining larger particles being in the size range from 53 .mu.m to 180 .mu.m. A powder with slow recrystallization rates, as evidenced by non-overlapping or slightly overlapping endothermic and exothermic peaks in their differential scanning calorimetry characteristics for scan rates of on the order of 10.degree. C. to 20.degree. C. per minute, will also result in sintered parts that are near-fully dense, with minimal dimensional distortion.

대표청구항 ▼

[ We claim:] [1.] A method of producing a three-dimensional object, comprising the steps of:applying a layer of a powder at a target surface, the powder comprised of a semi-crystalline organic polymer, the powder having a melting peak and a recrystallization peak, as shown in differential scanning c

[ We claim:] [1.] A method of producing a three-dimensional object, comprising the steps of:applying a layer of a powder at a target surface, the powder comprised of a semi-crystalline organic polymer, the powder having a melting peak and a recrystallization peak, as shown in differential scanning calorimetry traces, which slightly overlap when measured at a scanning rate of 10-20.degree. C./minute;directing energy at selected locations of the layer corresponding to the cross-section of the object to be formed in the layer, to fuse the powder thereat;repeating the applying and directing steps to form the object in layerwise fashion; andremoving unfused powder from the object.