Three-dimensional printing of porous load-bearing bioceramic scaffolds

This article reports on the use of the binder jetting three-dimensional printing process combined with sintering to process bioceramic materials to form micro- and macroporous three-dimensional structures. Three different glass-ceramic formulations, apatite–wollastonite and two silicate-based glasses, have been processed using this route to create porous structures which have Young’s modulus equivalent to cortical bone and average bending strengths in the range 24–36 MPa. It is demonstrated that a range of macroporous geometries can be created with accuracies of ±0.25 mm over length scales up to 40 mm. Hot-stage microscopy is a valuable tool in the definition of processing parameters for the sintering step of the process. Overall, it is concluded that binder jetting followed by sintering offers a versatile process for the manufacture of load-bearing bioceramic components for bone replacement applications

Shape Training of Nitinol Wire Using Three-Dimensional (3DP) Fixtures

The presented research focuses on work done at the University of Washington on process development for the training of nitinol shape memory alloy wire using Three Dimensional Printing (3DP). Fixtures are created using the commercial stainless steel printing system produced by Ex One. Superelastic nitinol wire is set by restraining the wire in a fixture and thermal processing. A two dimensional test array was designed and fabricated to examine the effects of fixture curvature on the final wire shape. Three dimensional coils and spheres were created to demonstrate the potential of this process for more complicated shapes.Mechanical Engineerin