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The purpose of this paper is to establish a scientific understanding for electrochemical infiltration of laser sintered (LS) preforms.

Electrochemical deposition techniques were modified to induce infiltration of nickel ions inside porous LS structures with deposition on pore walls.

This novel process is feasible and has the potential to produce fully dense parts. Both conductive and non‐conductive preforms can be infiltrated by this method.

Removal of trapped fluids and gases inside the porous structure is one of the major challenges in the described electrochemical infiltration process.

This work enables low‐cost production of structural parts. It expands the application base for additive manufacturing, especially laser sintering technology.

The novel process carried out in this research is energy efficient when compared to state‐of‐the‐art vacuum‐melt infiltration.

The proposed process is a novel method for facilitating room‐temperature infiltration of porous LS preforms.

This purpose of this paper is to provide an overview of the steps and processes behind successfully adapting novel materials, namely virgin glass and recycled glass, to three‐dimensional printing (3DP).

The transition from 3DP ceramic systems to glass systems will be examined in detail, including the necessary modifications to binder systems and printing parameters. The authors present preliminary engineering data on shrinkage, porosity, and density as functions of peak firing temperature, and provide a brief introduction to the complexities faced in realizing an adequate and repeatable firing method for 3D printed glass.

Shrinkage behavior for the 3D printed recycled glass showed significant anisotropy, especially beyond peak firing temperatures of 730°C. The average shrinkage ratios for the slow‐ and fast‐axes to the Z‐axis were 1:1.37 and 1:2.74, respectively. These extreme differences can be attributed to the layer‐by‐layer production method and binder burn‐off. At 760°C, the apparent porosity reached a minimum of 0.36 percent, indicative of asymptotic behavior that approaches a fully dense 3DP glass specimen. At low firing temperatures, the bulk density was similar to water, but increased to a maximum of 2.41 g/cm³. This indicates that 3DP recycled glass can behave similarly to common glass with accepted published bulk densities ranging from 2.4‐2.8 g/cm³.

Heating schedule analysis and optimization may reduce geometric variations, therefore, the firing method should be investigated in greater depth.

This paper provides a guide to successfully adopting glass to commercially available 3DP hardware. This research has also enabled rapid prototyping of recycled glass, a monumental step towards a sustainable future for 3DP.

Most current additive manufacturing (AM) processes are layer based. By converting a three‐dimensional model into two‐dimensional layers, the process planning can be dramatically simplified. However, there are also drawbacks associated with such an approach such as inconsistent material properties and difficulty in embedding existing components. The purpose of this paper is to present a novel AM process that is non‐layer based and demonstrate its unique capability.

An AM process named computer numerically controlled (CNC) accumulation has been developed. In such a layerless AM process, a fiber optic‐cable connected with an ultraviolet (UV) LED and related lens is served as an accumulation tool. The cable is then merged inside a tank that is filled with UV‐curable liquid resin. By controlling the on/off state of the UV‐LED and the multi‐axis motion of the cable, a physical model can be built by selectively curing liquid resin into solid.

It is found that the cured resin can be safely detached from the accumulation tool by applying a Teflon coating on the tip of the fiber‐optic cable, and controlling an appropriate gap between the cable and the base. The experimental results verified the curing and attaching force models.

A proof‐of‐concept testbed has been developed based on a curing tool that has a diameter around 2 mm. The relatively large tool size limits the geometry resolution and part quality of the built parts.

By incorporating multi‐axis tool motion, the CNC accumulation process can be beneficial for applications such as plastic part repairing, addition of new design features, and building around inserts.

The increasing interest in engineering structures made from multiple materials has led to corresponding interest in technologies, which can fabricate multi‐material parts. The purpose of this paper is to further explore of the multi‐material fabrication capabilities of ultrasonic consolidation (UC).

Various combinations of materials including titanium, silver, tantalum, aluminum, molybdenum, stainless steel, nickel, copper, and MetPreg^® were ultrasonically consolidated. Some of the materials were found to be effective as an intermediate layer between difficult to join materials. Elemental boron particles were added in situ between selected materials to modify the bonding characteristics. Microstructures of deposits were studied to evaluate bond quality.

Results show evidence of good bonding between many combinations of materials, thus illustrating increasing potential for multi‐material fabrication using UC.

Multi‐material fabrication capabilities using UC and other additive manufacturing processes is a critical step towards the realization of engineering designs which make use of functional material combinations and optimization.

The purpose of this paper is to describe work carried out as part of a £350,000 project aimed at improving understanding of polymer sintering processes. This particular package of research was performed in order to identify the effects of different section thicknesses (and therefore different thermal conditions) in parts produced by laser sintering (LS), on the resultant mechanical properties of these parts.

Laser sintered nylon‐12 parts were produced in a range of thicknesses between 2 and 6 mm, and in three different orientations, to identify the effects of each on the tensile properties of these parts.

Results indicated that, at any of the orientations tested, the section thickness had no significant effect on any of the main tensile properties, or on the repeatability of these properties. Crucially, this is in direct contradiction with the trends identified previously in this project, whereby changes in section thickness have been shown to correlate with changes in fracture toughness.

Further work could investigate a wider range of section thicknesses or geometries, in order to continue building a more complete picture of the effects of geometry on laser sintered part properties.

These results are directly applicable to designers using, or wishing to use, LS to manufacture their products.

Whilst there is a large range of published literature on the effects of processing parameters on mechanical properties of laser sintered parts, and on the resolution and accuracy achievable with these, there is minimal information available on the effects of geometry on mechanical properties. This paper therefore represents a novel addition to the global LS knowledge base.

The purpose of this paper is to determine the most‐practical means of transforming computer‐aided‐design models of custom clubfoot pedorthoses into functional pedorthoses for testing on patients in a clinical trial.

The materials used in conventional orthosis fabrication are not yet available for solid free‐form fabrication; therefore, to fabricate the pedorthoses, several approaches were considered, including direct manufacturing, additive‐based moulding, laser cutting of foam and combinations of several of these approaches.

The chosen approach of additively manufacturing the custom hard shell, and moulding the polyurethane‐foam insert, resulted in accurate, durable and effective pedorthoses that fit well, and could be adjusted as needed. The pedorthoses that were produced are currently being tested on the respective patients for their improvement in mobility and degree of clubfoot correction, and will continue through early 2010.

Additive manufacturing provides an ideal approach for generating the custom, end‐use hard‐ and soft‐layer patterns: each pedorthosis is truly unique; and the soft layer has regions of variable thickness. The advantage of this approach is the reduction in labour and the increase in degrees of design freedom available, compared to conventional methods of fabricating orthotic devices. Replacement inserts can be moulded in a matter of hours using this silicone‐moulding approach.

Several new approaches for fabricating custom orthotic devices were explored, and the related results are discussed. The goal of this paper is to convey the potential of the fabrication procedure used and lessons learned on this project to the rapid prototyping and orthotic communities.

The purpose of this paper is to familiarize the reader with the capabilities of EFAB technology, a unique additive manufacturing process which yields fully assembled, functional mechanisms from metal on the micro to millimeter scale, and applications in medical devices.

The process is based on multi‐layer electrodeposition and planarization of at least two metals: one structural and one sacrificial. After a period of initial commercial development, it was scaled up from a prototyping‐only to a production process, and biocompatible metals were developed for medical applications.

The process yields complex, functional metal micro‐components and mechanisms with tight tolerances from biocompatible metals, in low‐high production volume.

The process described has multiple commercial applications, including minimally invasive medical instruments and implants, probes for semiconductor testing, military fuzing and inertial sensing devices, millimeter wave components, and microfluidic devices.

The process described in this paper is unusual among additive fabrication processes in being able to manufacture in high volume, and in its ability to produce devices with microscale features. It is one of only a few additive manufacturing processes that can produce metal parts or multi‐component mechanisms.

The melt pool created by a laser is one of the most important factors affecting the quality of the deposit in a laser metal deposition (LMD) process. The high‐intensity infrared (IR) radiation emitted by the melt pool saturates a conventional camera sensor preventing useful data acquisition. The purpose of this paper is to discuss the development of a low‐cost vision system to monitor the size of the melt pool for in‐process quality control of the deposit.

According to the black body radiation theory, there is no radiation emitted in the ultraviolet (UV) region from the melt pool created in the LMD process. IR radiation and visible light are the only radiations inherent to the LMD process. UV illumination is utilized along with narrow band pass filters on a USB camera to achieve a clear image of the melt pool while IR radiation of the process is blocked out. The melt pool size and shape were closely monitored during the deposition process.

A clear image of the melt pool was obtained using a relatively low‐cost imaging system during laser deposition process.

Traditional approaches to vision systems in high‐intensity processes use a high‐speed video camera fitted with IR filters to prevent saturation of the camera sensor. Such systems are usually complex and expensive to run and maintain. This paper demonstrates an alternative and lower cost method to achieve in process monitoring in an LMD process.