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Selective inhibition of sintering (SIS) is a layered fabrication process which is capable of rapidly producing accurate functional parts out of polymers and metals using a relatively inexpensive machine. This article presents a brief overview of the research and development aimed at establishing the feasibility and the potential of the process.

Selective inhibition of sintering (SIS) is a new rapid prototyping method that builds parts in a layer‐by‐layer fabrication basis. SIS works by joining powder particles through sintering in the part's body, and by sintering inhibition of some selected powder areas. In this research, statistical tools were applied to improve some important properties of the parts fabricated by the SIS process. An investigation of surface quality and dimensional accuracy was conducted using response surface methodology and through analysis of the experimental results, the impact of the factors on them was modeled. After developing a desirability function model, process operating conditions for maximum desirability are identified. Finally, the desirability model is validated.

The purpose of this paper is to describe a heating system for the selective inhibition sintering (SIS) process that will produce uniform heat and minimize the polymer powder waste.

This research was conducted in two areas: the first was the production of uniform heat distribution. For this task, a lighting design software was used for the initial heater design. The result was then validated by thermal images, point‐by‐point temperature measurement, and physical part fabrication. The second area was the minimization of polymer powder waste. For this task, a finger‐based masking mechanism was designed, prototyped, and tested.

The lighting design software output illustrates that the square, crossed, and parallel patterns have very low variation and seem to be acceptable alternatives for the heating system pattern. Also, results show that the temperature variation for the ceramic heater is lower (therefore better) than the wire heater. Also, the study reveals that a finger‐based masking system design and prototype is very promising from the polymer powder waste‐saving standpoint.

Owing to the software limitation, radiation is the only source of heat transfer in this research (convection and conduction were not considered). Also, a limited number of patterns were examined for the heater design; this number can be expanded in future research.

A new design and development method has been proposed for the heating system for the SIS process that could lead to better heaters and waste‐reducing mechanisms for the SIS process and similar applications.

The main aim of this study is to generate curved-form cut on the edge of an adaptive layer. The resulting surface would have much less geometry deviation error and closely fit its computer aided design (CAD) model boundary.

This method is inspired by the manual peeling of an apple in which a knife's orientation and movement are continuously changed and adjusted to cut each slice with minimum waste. In this method, topology and geometry information are extracted from the previously generated adaptive layers. Then, the thickness of an adaptive layer and the bottom and top contours of the adjacent layers are fed into the proposed algorithm in the form of the contour and normal vector to create curved-form sloping surfaces. Following curved-form adaptive slicing, a customized machine path compatible with a five-axis abrasive waterjet (AWJ) machine will be generated for any user-defined sheet thicknesses.

The implemented system yields curved-form adaptive slices for a variety of models with diverse types of surfaces (e.g. flat, convex, and concave), different slicing direction, and different number of sheets with different thicknesses. The decrease in layer thickness and increase of the number of the sloped cuts can make the prototype as close as needed to the CAD model.

The algorithm is designed for use with five-axis AWJ cutting of any kind of geometrical complex surfaces. Future research would deal with the nesting problem of the layers being spread on the predefined sheet as the input to the five-axis AWJ cutter machine to minimize the cutting waste.

The algorithm generates adaptive layers with concave or convex curved-form surfaces that conform closely to the surface of original CAD model. This will pave the way for the accurate fabrication of metallic functional parts and tooling that are made by the attachment of one layer to another. Validation of the output has been tested only as the simulation model. The next step is the customization of the output for the physical tests on a variety of five-axis machines.

This paper proposes a new close to CAD design sloped-edge adaptive slicing algorithm applicable to a variety of five-axis processes that allow variable thickness layering and slicing in different orientations (e.g. AWJ, laser, or plasma cutting). Slices can later be bonded to build fully solid prototypes.