To investigate the effects of the infra‐red power level on sintering behaviour in the high speed sintering (HSS) process.
Single‐layer parts were produced using the HSS process, in order to determine the effect of the infra‐red power level on the maximum achievable layer thickness, and the degree of sintering. The parts were examined using both optical microscopy and contact methods.
It was initially expected that an increase in the infra‐red lamp powder might allow an increase in the depth of sintering that could be achieved, as a result of increased thermal transfer through the powder. However, results in fact indicated that there is a maximum layer thickness that can be achieved, as a result of part shrinkage in the z direction. Optical microscopy images have shown that a greater degree of sintering occurs at higher power levels, which would be expected to correspond to an improvement in the mechanical properties of the parts produced. These images also indicate that the radiation absorbing material forms in small “islands” on the powder bed surface. As sintering progresses, these islands begin to merge; this occurs to a greater extent at higher infra‐red lamp powers.
These results are based only on single layer parts. Further work will examine the sintering characteristics of multiple layer parts.
Results have shown that, whilst it is not possible to increase the achievable layer thickness of the parts produced by modifying the infra‐red lamp power, the degree of sintering can be improved greatly by increasing the power.
HSS is an entirely new process which is currently still under development; the results presented here will directly impact the direction of further development and research into this process.
The purpose of this study was to assess the suitability of micro-computed tomography as a non-destructive method to investigate the morphology of nylon 12 parts produced…
The purpose of this study was to assess the suitability of micro-computed tomography as a non-destructive method to investigate the morphology of nylon 12 parts produced by high-speed sintering (HSS). The investigation of the effect of changes in the lamp power on the properties of the fabricated parts was another purpose of this study.
Nylon 12 parts were manufactured using HSS with various lamp powers. Morphological properties of the parts were measured using micro-computed tomography. Ultimate tensile strength, elongation at break and Young’s modulus of the prepared parts were determined and compared. The effect of lamp power on the properties of the parts was then studied.
This paper proposes micro-computed tomography as a suitable technique to study the 3D structure of the parts produced by HSS. The effects of lamp power on the properties of the produced parts were also discussed.
The findings could result in an improvement in customisation of the parts for various applications through varying the lamp power. The level of lamp power could be tailored to obtain suitable part properties for a target application.
This study strengthens the fact that HSS is a promising additive manufacturing technique to produce nylon 12 parts, and the properties of the parts could be maximised using a suitable level of lamp power. The results showed that micro-computed tomography could be used as an efficient technique to investigate the morphology of the sintered parts.