Rapid prototyping and tooling system

A solid freeform fabrication process for making a three-dimensional object comprising the steps of:

• positioning a material deposition sub-system a selected distance above a work surface;
• operating said sub-system to deposit materials onto said work surface comprising the steps of (a) operating a multiple-channel liquid droplet deposition device of said deposition sub-system for supplying and ejecting multiple liquid compositions in a droplet form on demand onto selected spots of said work surface;
• (b) operating a focused heat source to produce a heat-affected zone on said work surface;
• and (c) operating a solid powder-dispensing device for discharging selected powder particles to said heat-affected zone for forming a molten weld pool of a predetermined size;
• said (a), (b), and (c) steps being operated in a predetermined sequence;
• during said material deposition process, moving said deposition sub-system and said work surface relative to one another in a plane defined by first and second directions and in a third direction orthogonal to said plane to form said liquid droplets and weld pool material into a three dimensional shape.

A process for making a multi-material three-dimensional object, comprising the steps of:

• creating an image of said three-dimensional object on a computer, said image including a plurality of segments defining said object;
• evaluating the data files representing said object to locate any un-supported feature of the object, followed by defining a support structure for the un-supported feature and creating a plurality of segments defining said support structure;
• generating program signals corresponding to each of said segments for both said object and said support structure in a predetermined sequence;
• providing a supply of selected liquid compositions and weld pool materials;
• operating a material deposition sub-system to deposit selected materials onto a work surface;
• said deposition step comprising ejecting said liquid compositions in a droplet form onto desired spots of said work surface and introducing a weld pool of molten materials on said work surface;
• during said deposition step, moving said deposition sub-system and said work surface in response to said programmed signals relative to one another in a plane defined by first and second directions and in a third direction orthogonal to said plane in a predetermined sequence of movements such that said deposition materials are deposited in free space as a plurality of segments sequentially formed so that the last deposited segment overlies at least a portion of the preceding segment in contact therewith to thereby form said support structure and said three-dimensional object on said work surface;
• removing said support structure from said work surface.