Three-dimensional printing of three-dimensional objects

Abstract

The present disclosure provides three-dimensional (3D) printing methods, apparatuses, systems and/or software to form one or more complex three-dimensional objects. The three-dimensional object may be formed by three-dimensional printing one or more methodologies. The three-dimensional object may comprise an overhang portion and/or cavity ceiling with diminished deformation and/or auxiliary support structures.

What is claimed is: 
     
         1 . A three-dimensional object, comprising:
 a plurality of layers of hardened material, wherein a single layer of the plurality of layers of hardened material includes (1) a first portion and (2) a second portion,   wherein the first portion is characterized as having a first microstructure; and   wherein an exterior surface of the second portion (i) corresponds to at least a fraction of an exterior surface of the three-dimensional object, and (ii) is characterized as having a second microstructure that is different than the first microstructure.   
     
     
         2 . The three-dimensional object of  claim 1 , wherein the second microstructure comprises a repeating pattern. 
     
     
         3 . The three-dimensional object of  claim 1 , wherein the repeating pattern runs along the exterior surface. 
     
     
         4 . The three-dimensional object of  claim 1 , wherein the three-dimensional object comprises a portion in which the first portion contacts the second portion. 
     
     
         5 . The three-dimensional object of  claim 1 , further comprising one or more intermediate portions between the first portion and the second portion. 
     
     
         6 . The three-dimensional object of  claim 1 , wherein the plurality of layers comprises at least one layer that does not include a first portion and a second portion having different microstructures. 
     
     
         7 . The three-dimensional object of  claim 1 , wherein the second portion has a thickness ranging from about 20 micrometers to about 1000 micrometers. 
     
     
         8 . The three-dimensional object of  claim 1 , wherein the first microstructure is formed at a first solidification rate, wherein the second microstructure is formed at a second solidification rate. 
     
     
         9 . The three-dimensional object of  claim 8 , wherein the first solidification rate is greater than the second solidification rate. 
     
     
         10 . The three-dimensional object of  claim 8 , wherein the first solidification rate and the second solidification rate are associated with a cooling rate during generation of the hardened material. 
     
     
         11 . The three-dimensional object of  claim 1 , wherein the first microstructure comprises a first melt pool and/or a first grain, and wherein the second microstructure comprise a second melt pool and/or a second grain. 
     
     
         12 . The three-dimensional object of  claim 11 , wherein grains of the second microstructure of the second portion are more ordered as compared to grains of the first microstructure of the first portion. 
     
     
         13 . The three-dimensional object of  claim 11 , wherein the first grain comprises a first constituent and wherein the second grain comprises a second constituent, wherein the first constituent differs from the second constituent in at least one member selected from the group consisting of fundamental length scale, chemical makeup, crystal structure, and metallurgical microstructure. 
     
     
         14 . The three-dimensional object of  claim 13 , wherein the first constituent comprises a first crystal structure or a first metallurgical microstructure, and wherein the second constituent comprises a second crystal structure or a second metallurgical microstructure. 
     
     
         15 . The three-dimensional object of  claim 1 , wherein the first portion comprises a first set of grains, wherein the second portion comprises a second set of grains, wherein grains of the second set have on average a fundamental length scale that is larger than a corresponding fundamental length scale of grains of the first set. 
     
     
         16 . The three-dimensional object of  claim 15 , wherein the fundamental length scale comprises a width or a length. 
     
     
         17 . The three-dimensional object of  claim 1 , wherein the second portion is directly attached to the first portion. 
     
     
         18 . The three-dimensional object of  claim 1 , wherein the second portion is characterized by a plurality of tiles, wherein centers of adjacent tiles of the plurality of tiles are substantially uniformly spaced apart from one another. 
     
     
         19 . The three-dimensional object of  claim 18 , wherein at least two adjacent tiles of the plurality of tiles overlap with one another. 
     
     
         20 . The three-dimensional object of  claim 1 , wherein the second portion is a bottom skin portion of an overhang structure of the three-dimensional object, wherein a vector normal to the exterior surface at a point on the exterior surface, forms an angle by intersecting with (1) a layering plane or (2) a plane parallel to the layering plane. 
     
     
         21 . The three-dimensional object of  claim 20 , wherein the angle is at least sixty degrees and at most ninety degrees, wherein the vector is directed into the overhang. 
     
     
         22 . The three-dimensional object of  claim 21 , wherein the exterior surface has a surface roughness (Sa) of at most about 20 micrometers as measured by a surface profilometer.