Additive manufacturing: A framework for implementation

Layered manufacturing (LM) is emerging as a new manufacturing technology that can enhance the scope of manufacturing. One of the essential tasks in LM is process planning. This paper defines, conceptualizes and reviews the literature in this emerging area. The paper concludes with future projections on the possible directions of research in this area.

A review of process planning techniques in layered manufacturing

As more choices of materials and build processes become available in layered manufacturing (LM), it is increasingly important to identify fundamental problems that underlie the entire field. Determination of best build orientation and minimizing build cost of a part are two such issues that must be considered in any LM process. By decoupling the solution to these problems from a specific LM technology, not only can the solution be applied to a variety of processes, but more realistic cost comparisons of parts built on different machines become possible.

Part orientation and build cost determination in layered manufacturing

By synergistically combining additive and subtractive processes within a single workstation, the relative merits of each process may be harnessed. This facilitates the manufacture of internal, overhanging and high aspect ratio features with desirable geometric accuracy and surface characteristics. The ability to work, measure and then rework material enables the reincarnation and repair of damaged, high-value components. These techniques present significant opportunities to improve material utilisation, part complexity and quality management in functional parts. The number of single platform workstations for hybrid additive and subtractive processes (WHASPs) is increasing. Many of these integrate additive directed energy deposition (DED) with subtractive CNC machining within a highly mobile multi-axis machine tool. Advanced numerical control (NC), and computer aided design (CAD), manufacture (CAM) and inspection (CAI) help to govern the process. This research reviews and critically discusses salient published literature relating to the development of WHASPs, and identifies future avenues for research and development. It reports on state-of-the-art WHASP systems, identifying key traits and research gaps. Finally, a future vision for WHASPs and other hybrid machine tools is presented based upon emerging trends and future opportunities within this research area.

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Hybrid additive and subtractive machine tools – Research and industrial developments

A programming interface provides functions for generating applications, documents, media presentations and other content. These functions allow developers to obtain services from an operating system, object model service, or other system or service.

Programming interface for a computer platform

Disclaimer Certain commercially available hardware and software products are identified in this report to provide representative examples of current practice and to facilitate understanding of the issues discussed. Their identification does not imply any approval or endorsement of those products by the National Institute of Standards and Technology, nor does it imply that the products identified are necessarily the best available for their purpose.

An Assessment of Data Requirements and Data Transfer Formats for Layered Manufacturing

Survey of Process Planning Techniques for Layered Manufacturing

A homogenization method has been recently developed to optimize the topology of a structure. This method will suggest a structural topology, but the results will be in finite element form. Most engineering applications, however, require smooth structures, whether the faces of the structures be planar or curved. Given the topology of a three-dimensional structure as suggested by the homogenization method, an algorithm is developed to interpret the structure and generate a smooth, manufacturable surface representation of the structure. Structures designed by the homogenization method can be quite complex and traditional manufacturing techniques may not be well suited for constructing them. Layered manufacturing is adopted for producing such structures and it is shown how to generate the necessary data for this novel manufacturing technique from the surface model of the structure. Some steps of the algorithm require designer inputs. Examples are given which demonstrates this algorithm.

Construction of a Surface Model and Layered Manufacturing Data From 3D Homogenization Output

An integrated process planning system for layered manufacturing (LM) reduces the time between design and part fabrication and improves the quality of the final part. Process planning for most LM processes includes part orientation, support structure generation, slicing, and path planning. In this paper we describe an integrated process planning system we are developing. Our software accommodates both novel and traditional design models as input, and supports a variety of LM processes. The modules described in this paper include Solid Builder Module, which generates a solid model from design data such as medical images, surface functions, or digital elevation models; Orientation Module, which determines the optimal build orientation of a part and automatically generates the support structures required; and Adaptive Slicing Module, which adaptively slices the part.

Anne L. Marsan

Papers

A review of process planning techniques in layered manufacturing

An Assessment of Data Requirements and Data Transfer Formats for Layered Manufacturing

Survey of Process Planning Techniques for Layered Manufacturing

Construction of a Surface Model and Layered Manufacturing Data From 3D Homogenization Output

An Integrated Software System for Process Planning for Layered Manufacturing