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Integrating additive manufacturing (AM) tools in traditional mold-making provides complex yet affordable sand molds and cores. AM processes such as selective laser sintering (SLS) and Binder jetting three-dimensional printing (BJ3DP) are widely used for patternless sand mold and core production. This study aims to perform an in-depth literature review to understand the current status, determine research gaps and propose future research directions. In addition, obtain valuable insights into authors, organizations, countries, keywords, documents, sources and cited references, sources and authors.

This study followed the systematic literature review (SLR) to gather relevant rapid sand casting (RSC) documents via Scopus, Web of Science and EBSCO databases. Furthermore, bibliometrics was performed via the Visualization of Similarities (VOSviewer) software.

An evaluation of 116 documents focused primarily on commercial AM setups and process optimization of the SLS. Process optimization studies the effects of AM processes, their input parameters, scanning approaches, sand types and the integration of computer-aided design in AM on the properties of sample. The authors performed detailed bibliometrics of 80 out of 120 documents via VOSviewer software.

This review focuses primarily on the SLS AM process.

A SLR and bibliometrics using VOSviewer software for patternless sand mold and core production via the AM process.

This study addresses a gap in the knowledge on how longitudinal engagement in a school improvement initiative influences change in middle leaders’ (MLs') interactions and assesses how school–university partnerships around school improvement can support teachers with formal leadership roles (i.e. MLs’) leadership development.

Using a two-year longitudinal research design, university staff facilitated middle leadership training in a school-defined improvement initiative on lesson study. Results from a pre-test followed by two post-tests administered at one-year intervals were collected on social networks. Analyses examined changes in indegree and brokerage patterns among groupings of senior leaders (SL), subject leaders, cross-school specialists and teachers.

Accounting for staffing changes, 27 of 67 staff members participated in each survey, yielding 1,623 distinct ties connecting school members. Over the first year, advice-seeking increased by 225%. SLs’ initial propensity to consult peers shifted towards MLs and teachers. Subject leaders advising other leaders and teachers increased tenfold. Teachers’ peer-to-peer consultation increased by 2,000%. Specialists with school-wide responsibilities became the dominant group for advising other leaders, such as SLs and subject leaders. These shifts were sustained over the second year.

The study demonstrates that engagement in the school–university partnership support and the corresponding structural changes stimulated robust cross-school dialogue among teachers and various leaders. Brokerage patterns indicated an enhanced role for MLs in driving the school-defined improvement initiative which corresponded to university-designed development activities.

Selective laser sintering (SLS) is an essential technology in the field of additive manufacturing. However, SLS technology is limited by the traditional point-laser sintering method and has reached the bottleneck of efficiency improvement. This study aims to develop an image-shaped laser sintering (ISLS) system based on a digital micromirror device (DMD) to address this problem. The ISLS system uses an image-shaped laser light source with a size of 16 mm × 25.6 mm instead of the traditional SLS point-laser light source.

The ISLS system achieves large-area image-shaped sintering of polymer powder materials by moving the laser light source continuously in the x-direction and updating the sintering pattern synchronously, as well as by overlapping the splicing of adjacent sintering areas in the y-direction. A low-cost composite powder suitable for the ISLS system was prepared using polyether sulfone (PES), pinewood and carbon black (CB) powders as raw materials. Large-sized samples were fabricated using composite powder, and the microstructure, dimensional accuracy, geometric deviation, density, mechanical properties and feasible feature sizes were evaluated.

The experimental results demonstrate that the ISLS system is feasible and can print large-sized parts with good dimensional accuracy, acceptable geometric deviations, specific small-scale features and certain density and mechanical properties.

This study has achieved the transition from traditional point sintering mode to image-shaped surface sintering mode. It has provided a new approach to enhance the system performance of traditional SLS.

This paper aims to investigate and explain the dual fracture behaviour of PA12 specimens sintered by selective laser sintering (SLS) as a function of wall thickness and build direction with a powder mixture 30:70. To achieve this objective, research related to chemical, thermal and structural behaviours as a function of the input variables was carried out to describe and explain why ductile-fragile behaviour occurs during fractures under uniaxial tension manufactured via a methodology of material analysis and manufacturing processes.

The factorial design 32 relates the fracture of PA12 tensile specimens to the horizontal, transverse and vertical build directions at 2.0, 2.5 and 3.0 mm thicknesses, respectively. Fractographic images revealed the fracture surfaces and their dual ductile-fragile behaviour related to the specimens’ measured crystalline, thermal, surface and chemical properties.

The study showed that thermal property variables differ depending on the input variables. The wall thickness variable affected this morphology the most, showing the highest percentage of the ductile area, followed by the transverse and vertical directions. It was determined that the failure in the vertical direction is due to crystalline gradients associated with the layer-by-layer construction process. The pore density may be closely related to generating ductile and brittle areas.

In this paper, fracture characterisation is performed based on the mechanical, chemical, structural, thermal and morphological properties of PA12 manufactured by SLS. In addition, a heatmap of porosities in cross-sections is constructed using a machine learning model (k-means) related to dual fracture behaviour. This research revealed significant differences in the fracture type according to the build direction. In addition, thin-section fractography provides a more detailed explanation of the fragile behaviour of the vertical direction associated with crystalline changes due to the direction of the sintering layers.

The consolidation process and morphology evolution in ceramics-based additive manufacturing (AM) are still not well-understood. As a way to better understand the ceramic selective laser sintering (SLS), a dynamic three-dimensional computational model was developed to forecast thermal behavior of hydroxyapatite (HA) bioceramic.

AM has revolutionized automotive, biomedical and aerospace industries, among many others. AM provides design and geometric freedom, rapid product customization and manufacturing flexibility through its layer-by-layer technique. However, a very limited number of materials are printable because of rapid melting and solidification hysteresis. Melting-solidification dynamics in powder bed fusion are usually correlated with welding, often ignoring the intrinsic properties of the laser irradiation; unsurprisingly, the printable materials are mostly the well-known weldable materials.

The consolidation mechanism of HA was identified during its processing in a ceramic SLS device, then the effect of the laser energy density was studied to see how it affects the processing window. Premature sintering and sintering regimes were revealed and elaborated in detail. The full consolidation beyond sintering was also revealed along with its interaction to baseplate.

These findings provide important insight into the consolidation mechanism of HA ceramics, which will be the cornerstone for extending the range of materials in laser powder bed fusion of ceramics.

The purpose of this exploratory case study was to investigate the role of School Leaders (SLs) in building Professional Learning Communities (PLCs) in schools, as well as to expand a literature-driven PLC model within the Pakistani context.

The study involved the purposive selection of two schools affiliated with a university. The sample comprised one school leader, one academic coordinator and five teachers from each school, altogether 14 participants. The participants shared similar demographic characteristics. Semi-structured interviews were conducted to collect data, which were analysed thematically.

The findings of the study revealed that both schools have created PLCs to some extent and that school goals and culture were contributing factors in building these communities. Additionally, the SLs played a key role in promoting PLCs by encouraging teacher collaboration. The study concludes that SLs have the potential to strategize their actions to foster positive professional relations among teachers and ensure their well-being.

The study contributes to the literature on professional communities in Pakistan by validating a literature-driven PLC model. The model emphasizes collaboration among teachers, which can be facilitated by SLs. As such, the study implicates SLs in prioritizing the professional development of teachers to enhance student learning and achieve school success.

This study is unique in expanding a literature-driven PLC model within the Pakistani context, with a focus on teacher collaboration as facilitated by SLs. The model has the potential for replication in other contexts and can serve as a useful tool for future research.

Three-dimensional (3D) casting means using additive manufacturing (AM) techniques to print the mould for casting the cast tool. The printed mould, however, should be checked for its dimensional accuracy. 3D scanning can be used for the same. The purpose of this study is to combine the different AM techniques for 3D casting with 3D scanning to produce parts with close tolerance for preparing electrical discharge machining (EDM) electrodes.

The four processes, namely, stereolithography, selective laser sintering, fused deposition modelling and vacuum casting, are used to print the casting mould. The mould is designed in two halves, assembled to form a complete mould. The mould is 3D scanned in two stages: before and after using it as a casting mould. The mould's average and maximum dimensional deviations are calculated using 3D-scanned results. The eutectic Sn-Bi alloy is cast in the mould. The surface roughness of the mould and the cast tool are measured.

The cast tool is selected from the four processes in terms of dimensional accuracy and surface finish. The same is electroplated with copper. The microstructure of the cast tool (low-melting-point alloy) and deposited copper is analysed using a scanning electron microscope. Energy dispersive spectroscopy and X-ray diffraction techniques are used to verify the composition of the cast and coated alloy. The electroplated tool is finally tested on the EDM setup. The material removal rate and tool wear are measured. The performance is compared with a solid copper tool. The free-form customised EDM mould is also prepared, and the profile is cast out. The same is tested on the EDM. Thus, the developed path can be successfully used for rapid tooling applications.

The eutectic composition of Sn-Bi is cast in the 3D-printed mould using different AM techniques combined with 3D scanning quality to check its feasibility as an EDM electrode, which is a novel work and has not been done previously.

A key challenge for exporters and international marketing/purchasing managers is formulating strategic responses to deal with geopolitical disruptions during a trade war between superpowers. While past studies provide insightful analysis of the influence of changes in the institutional environment (regulatory pressures) on national and firm-level trade activities, they tend to ignore the association between inward (sourcing) or outward (export) international activities of firms during a trade war. In this study, we aim to explore various strategic options employed by third-party SME exporters in response to geopolitical disruptions, institutional pressures and constraints during a trade war.

We adopted a qualitative methodology and applied a hermeneutical approach in collecting, analysing and theorising interview findings. We conducted interviews with 15 owners or senior managers from 12 Australian and New Zealand exporters that exported or sourced significantly from at least one party of the trade war, the USA or China, between 2018 and 2020.

Our study developed a typology of fencing vs. balancing for explaining third-party SME exporters’ response strategies in terms of export market and international sourcing locations during a trade war. Fencing strategy centres on location choice decisions based on a fence or a secure buffer zone. Balancing strategy focuses on leveraging opportunities outside the conflict zone, i.e. third-party countries. Our study finds that exporters’ location choice decisions are influenced by a number of institutional factors during the trade war.

Firstly, our study examined only the early phase of the trade war under the “Trump” era. Future research may consider a longitudinal study design that examines exporters’ responses to global political uncertainty over a longer term. Secondly, we chose Australia and New Zealand as the focal context of this study. Future research could investigate exporters from other third-party countries that have different institutional conditions during the US-China trade war.

Firstly, an exporting firm should monitor and assess closely the wider changes in international relations between their home country’s major security partner and major trading partner, and the impact of these changes on the political risks of operating in international locations. Secondly, as the trade war intensifies, the fencing option needs to be given a greater weight than the balancing option in the strategic decision making of an exporter from a third-party country. Lastly, we encourage marketers and managers to reflect on and differentiate short-term and long-term benefits in strategic market-sourcing location decisions.

Our study makes a pioneering effort to theorise the linkages between institutional factors and the combined evaluation of export market selection and sourcing location selection choices under global political uncertainty based on the institution-based view. We present a conceptual framework highlighting the importance of institutional avoidance, embeddedness, comparative institutional advantages and multiple institutional logics for SME exporters’ international location selections during the trade war. Furthermore, we combine these institutional factors into two overarching constructs namely institutional buffer and institutional pluralism.

This study aims to propose the reuse of PA12 (powder) in another AM process, binder jettiinng, which is less sensitive to the chemical and mechanical degradation of the powder after multiple cycles in the laser system.

The experimental process for evaluating the reuse of SLS powders in a subsequent binder jetting process consists of four phases: powder characterization, bonding analysis, mixture testing and mixture characteristics. Analyses were carried out using techniques such as Fourier Transform Infrared Spectroscopy, scanning electron microscopy, thermogravimetric analysis and stress–strain tests for tension and compression. The surface roughness, color, hardness and density of the new mixture were also determined to find physical characteristics. A Taguchi design L8 was used to search for a mixture with the best mechanical strength.

The results indicated that the integration of waste powder PA12 with calcium sulfate hemihydrate (CSH) generates appropriate particle distribution with rounded particles of PA12 that improve powder flowability. The micropores observed with less than 60 µm, facilitated binder and infiltrant penetration on 3D parts. The 60/40 (CSH-PA12) mixture with epoxy resin postprocessing was found to be the best-bonded mixture in mechanical testing, rugosity and hardness results. The new CSH-PA12 mixture resulted lighter and stronger than the CSH powder commonly used in binder jetting technology.

This study adds value to the polymer powder bed fusion process by using its waste in a circular process. The novel reuse of PA12 waste in an established process was achieved in an accessible and economical manner.

This study aims to address challenges in the Laser Powder Bed Fusion process of polymers, focusing on the considerable amount of unsintered powder left post-printing. The objective is to understand the altered properties of this powder and find solutions to improve the process, reduce waste and explore reusing reprocessed powder.

A novel methodology is used to generate reprocessed powder without traditional printing, reducing time, cost and waste. The approach mimics the ageing effects during the printing process, providing insights into particle size distribution and thermal behaviour.

Results reveal insights into artificial ageing, showing an 8.2% decrease in particle size (60.256–69.183 µm) and a 9.1% increase in particle size (17.378–19.953 µm) compared to unsintered powder. Thermal behaviour closely mirrors used powders, with variations in enthalpy of fusion (−0.55% to 2.69%) and degree of crystallinity (0.19% to 2.64%). The proposed methodology produces results that differ from those due to printing under 3% from a thermal point of view. The new process reduces the time needed for aged powder, contributing to cost savings and waste reduction.

The study introduces a novel method for reprocessed powder generation, deviating from traditional printing. The originality lies in artificially ageing powders, providing comparable results to actual printing. This approach offers efficiency, time savings and waste reduction in the Laser Powder Bed Fusion process, presenting a valuable avenue for further research.