Rapid Prototyping Journal

Gonçalves, Sérgio B; Dantas, Pedro; Guedes de Melo, Francisco; Gouveia, João; Guimarães Consciência, José; Martins, Jorge; Silva, Miguel Tavares da

2025 Rapid Prototyping Journal

doi: 10.1108/rpj-02-2024-0061

Arthroscopic osteochondroplasty is a minimally invasive procedure that has been used to treat femoroacetabular impingement syndrome, leading to significant improvements in patients’ clinical outcomes and quality of life. However, some studies suggest that inadequate bone resection can substantially alter hip biomechanics. These modifications may generate different contact profiles and higher contact forces, increasing the risk of developing premature joint degeneration. To improve control over bone resection and biomechanical outcomes during arthroscopic osteochondroplasty surgery, this study aims to present a novel system for measuring femoroacetabular contact forces.Design/methodology/approachFollowing a structured design process for the development of medical devices, the steps required for its production using additive manufacturing with material extrusion and easily accessible sensors are described. The system comprises two main devices, one for measuring femoroacetabular contact forces and the other for quantifying the force applied by the assistant surgeon during lower limb manipulation. The hip device was designed for use within an arthroscopic environment, eliminating the need for additional portals.FindingsTo evaluate its performance, the system was first tested in a laboratory setup and later under in-service conditions. The 3D printing parameters were tuned to ensure the watertighness of the device and sustain the intraoperative fluid pressures. The final prototype allowed for the controlled measurement of the hip contact forces in real-time.Originality/valueUsing additive manufacturing and readily available sensors, the present work presents the first device to quantify joint contact forces during arthroscopic surgeries, serving as an additional tool to support the surgeon’s decision-making process regarding bone resection.

Benegra Denadai, Bruno; Foggiatto, José Aguiomar; Triches Dornbusch, Peterson; Pioli Torres, Maria Fernanda; Luersen, Marco Antônio

2025 Rapid Prototyping Journal

doi: 10.1108/rpj-04-2024-0176

This paper aims to design and manufacture an equine hand prosthesis using additive manufacturing, with an estimated useful life of one year. This approach offers a fast and affordable manufacturing alternative while ensuring the horse's safety, comfort and functionality.Design/methodology/approachThe ground reaction force and the frequency of a horse’s walking were obtained from the literature. Mechanical tests were conducted on specimens with different manufacturing directions to determine the mechanical properties of the printed material. Finite element simulations, along with fatigue equations were used to design a geometry that respected the stress constraints. Subsequently, a prototype was manufactured in thermoplastic polyurethane using additive manufacturing technique.FindingsWith the aid of the proposed methodology, a new low-cost equine hand prosthesis is developed, and a prototype is manufactured. And in accordance with the design requirements, this prosthesis is intended to exhibit proper durability.Social implicationsThis work presents an alternative way for horses facing amputation, offering a solution where euthanasia can be avoided through the use of a prosthesis to replace a part of the amputated limb. This approach could not only extend the reproductive life of matrices with high commercial value but also preserve the lives of animals with sentimental value to the owner.Originality/valueTo the best of the authors' knowledge, this is the first study of an equine hand prosthesis model designed for and manufactured by additive manufacturing.

Chi, Yitian; Murali, Narayanan; Li, Xiaochun

2025 Rapid Prototyping Journal

doi: 10.1108/rpj-01-2024-0033

High-performance wrought aluminum alloys, particularly AA6061, are pivotal in industries like automotive and aerospace due to their exceptional strength and good response to heat treatments. Investment casting offers precision manufacturing for these alloys, because casting AA6061 poses challenges like hot cracking and severe shrinkage during solidification. This study aims to address these issues, enabling crack-free investment casting of AA6061, thereby unlocking the full potential of investment casting for high-performance aluminum alloy components.Design/methodology/approachNanotechnology is used to enhance the investment casting process, incorporating a small volume fraction of nanoparticles into the alloy melt. The focus is on widely used aluminum alloy 6061, utilizing rapid investment casting (RIC) for both pure AA6061 and nanotechnology-enhanced AA6061. Microstructural characterization involved X-ray diffraction, optical microscopy, scanning electron microscopy, differential scanning calorimetry and energy dispersive X-ray spectroscopy. Mechanical properties were evaluated through microhardness and tensile testing.FindingsThe study reveals the success of nanotechnology-enabled investment casting in traditionally challenging wrought aluminum alloys like AA6061. Achieving crack-free casting, enhanced grain morphology and superior mechanical properties, because the nanoparticles control grain sizes and phase growth, overcoming traditional challenges associated with low cooling rates. This breakthrough underscores nanotechnology's transformative impact on the mechanical integrity and casting quality of high-performance aluminum alloys.Originality/valueThis research contributes originality and value by successfully addressing the struggles in investment casting AA6061. The novel nano-treating approach overcomes solidification defects, showcasing the potential of integrating nanotechnology into rapid investment casting. By mitigating challenges in casting high-performance aluminum alloys, this study paves the way for advancements in manufacturing crack-free, high-quality aluminum alloy components, emphasizing nanotechnology's transformative role in precision casting.

Patil, Yogesh; Akarte, Milind; Karunakaran, K. P.; Patel, Ashik Kumar; Mittal, Yash G.; Gote, Gopal Dnyanba; Mehta, Avinash Kumar; Ely, Ronald; Shinde, Jitendra

2025 Rapid Prototyping Journal

doi: 10.1108/rpj-12-2023-0434

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.Design/methodology/approachThis 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.FindingsAn 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.Research limitations/implicationsThis review focuses primarily on the SLS AM process.Originality/valueA SLR and bibliometrics using VOSviewer software for patternless sand mold and core production via the AM process.

Prakash, Adarsh; Kore, Sachin Dnyandeo

2025 Rapid Prototyping Journal

doi: 10.1108/rpj-02-2024-0094

This study aims to investigate the effect of copper and titanium micropowder addition on the mechanical and metallurgical properties of additively manufactured low-carbon steel, aiming to produce a modified (multiphase) steel with ferritic low-carbon steel using in situ micropowder addition during wire arc direct energy deposition (WA-DED).Design/methodology/approachA robotic arm equipped with a GMA welding source deposited ER70S6 filler wire on AISI S235 substrate steel using WA-DED. Cu and Ti micropowders were interspersed between layers for microstructural modifications. Microscopy, spectroscopy, diffraction and mechanical testing were used to evaluate the properties of the deposited samples.FindingsIncorporating Cu and Ti micropowders significantly enhanced the yield and tensile strength of the deposited material, showing an 83% increase in yield strength and a 33% increase in tensile strength. Microstructural analysis identified key phases such as ferrite, pearlite, bainite, retained austenite and martensite/austenite, with Cu and Ti acting as grain refiners. Nanoscaled Cu precipitates contribute to enhanced low-temperature toughness and a 150% improvement in impact strength at −30°C.Originality/valueThis study presents a novel approach to overcome the limitations of the available alloys (filler materials). This can be achieved by introducing in situ micropowder alloying during the WA-DED process. The micropowder addition allows altering the properties of the deposited material without changing the parent filler material itself, achieving the desired composition. With this approach, there is no need to manufacture the filler material with the preferred alloy composition separately and then carry out the deposition process.

Turk, Tunay; Dominguez, Cesar E.; Sutton, Austin T.; Bernardin, John D.; Park, Jonghyun; Leu, Ming C.

2025 Rapid Prototyping Journal

doi: 10.1108/rpj-01-2024-0042

This paper aims to present spot pattern welding (SPW) as a scanning strategy for laser-foil-printing (LFP) additive manufacturing (AM) in place of the previously used continuous pattern welding (CPW) (line-raster scanning). The SPW strategy involves generating a sequence of overlapping spot welds on the metal foil, allowing the laser to form dense and uniform weld beads. This in turn reduces thermal gradients, promotes material consolidation and helps mitigate process-related risks such as thermal cracking, porosity, keyholing and Marangoni effects.Design/methodology/approach304L stainless steel (SS) feedstock is used to fabricate test specimens using the LFP system. Imaging techniques are used to examine the melt pool dimensions and layer bonding. In addition, the parts are evaluated for residual stresses, mechanical strength and grain size.FindingsCompared to CPW, SPW provides a more reliable heating/cooling relationship that is less dependent on part geometry. The overlapping spot welds distribute heat more evenly, minimizing the risk of elevated temperatures during the AM process. In addition, the resulting dense and uniform weld beads contribute to lower residual stresses in the printed part.Originality/valueTo the best of the authors’ knowledge, this is the first study to thoroughly investigate SPW as a scanning strategy using the LFP process. In general, SPW presents a promising strategy for securing embedded sensors into LFP parts while minimizing residual stresses.

Cerda-Avila, Steffany N.; Medellín-Castillo, Hugo I.

2025 Rapid Prototyping Journal

doi: 10.1108/rpj-01-2024-0051

This study aims to present and evaluate a novel analytical model to predict the structural properties of parts fabricated by fused filament fabrication (FFF) along any non-orthogonal direction.Design/methodology/approachA new analytical model to estimate the ultimate tensile stress (UTS) and elastic modulus (E) of polylactic acid (PLA)-FFF parts fabricated in any non-orthogonal build orientation, is proposed. The new model is based on an ellipsoid, two angles that define the orientation with respect to the build axes, the infill value and the structural properties along the build axes. The proposed model is evaluated by comparing the UTS and E properties predicted by this model, with the results obtained from experimental tensile tests on PLA-FFF specimens manufactured using variable infill values and non-orthogonal build orientations.FindingsThe proposed model is able to predict with good precision the structural properties of PLA-FFF parts along any direction and infill value.Research limitations/implicationsAlthough the study and results are limited to the UTS and E tensile properties of PLA-FFF components, the model may be extended to other materials or similar additive manufacturing processes.Practical implicationsThe new proposed model is able to determine the structural properties of FFF components in any direction, so it can be used during the design process of FFF parts, reducing the need for experimental tests and speeding up the product development process.Originality/valueExisting models to predict the structural properties of FFF components are limited to orthogonal build orientations (X, Y and Z); however, the new proposed model is able to predict the tensile properties in any direction and infill value. In addition, a new set of experimental data about the structural behaviour of PLA-FFF parts along non-orthogonal build orientations is provided, extending the existing results in the literature.

Li, Gang; Song, Shuainan; Cai, Qun; Wu, Biao; Wen, Zhichao

2025 Rapid Prototyping Journal

doi: 10.1108/rpj-03-2024-0107

For the purpose of saving nickel, this study aims to develop new duplex stainless steel cored wires suitable for wire arc additive manufacturing (WAAM) with the addition of nitrogen.Design/methodology/approachThe effect of nitrogen content on the microstructure and mechanical properties of the thin-walled deposits is investigated in detail.FindingsThe microstructure of thin-walled deposits mainly consists of austenite, ferrite and secondary austenite. With increasing nitrogen content, the austenite in the deposited metals increases. The austenite proportion in the bottom region is more than that in the top region of the deposited metals. The χ phase is randomly distributed at the grain boundaries and within ferrite. The σ phase is mainly precipitated at ferrite and austenite grain boundaries. With increasing nitrogen content, the tensile strength of the deposited metals increases, but the impact toughness of the deposited metals deteriorates.Originality/valueThis study proposes new duplex stainless steel cored wires for WAAM, which realizes the objective of saving nickel.

Sharabian, Elmira; Khorasani, Mahyar; Gulizia, Stefan; Ghasemi, Amir Hossein; MacDonald, Eric; Downing, David; Rolfe, Bernard; Brandt, Milan; Leary, Martin

2025 Rapid Prototyping Journal

doi: 10.1108/rpj-03-2024-0141

This study aims to comprehensively investigate the electron beam powder bed fusion (EB-PBF) process for copper, offering validated estimations of melt pool temperature and morphology through numerical and analytical approaches. This work also assesses how process parameters influence the temperature fluctuations and the morphological changes of the melt pool.Design/methodology/approachTwo distinct methods, an analytical model and a numerical simulation, were used to assess temperature profiles, melt pool morphology and associated heat transfer mechanisms, including conduction and keyhole mode. The analytical model considers conduction as the dominant heat transfer mechanism; the numerical model also includes convection and radiation, incorporating specific parameters such as beam power, scan speed, thermophysical material properties and powder interactions.FindingsBoth the analytical model and numerical simulations are highly correlated. Results indicated that the analytical model, emphasising material conduction, exhibited exceptional precision, although at substantially reduced cost. Statistical analysis of numerical outcomes underscored the substantial impact of beam power and scan speed on melt pool morphology and temperature in EB-PBF of copper.Originality/valueThis numerical simulation of copper in EB-PBF is the first high-fidelity model to consider the interaction between powder and substrate comprehensively. It accurately captures material properties, powder size distribution, thermal dynamics (including heat transfer between powder and substrate), phase changes and fluid dynamics. The model also integrates advanced computational methods such as computational fluid dynamics and discrete element method. The proposed model and simulation offer a valuable predictive tool for melt pool temperature, heat transfer processes and morphology. These insights are critical for ensuring the bonding quality of subsequent layers and, consequently, influencing the overall quality of the printed parts.

Passari, Émerson dos Santos; Lauermann, Carlos Henrique; Souza, André J.; Silva, Fabio Pinto; Barros, Rodrigo Rodrigues de

2025 Rapid Prototyping Journal

doi: 10.1108/rpj-04-2024-0165

The rapid growth of 3D printing has transformed the cost-effective production of prototypes and functional items, primarily using extrusion technology with thermoplastics. This study aims to focus on optimizing mechanical properties, precisely highlighting the crucial role of mechanical compressive strength in ensuring the functionality and durability of 3D-printed components, especially in industrial and engineering applications.Design/methodology/approachUsing the Box−Behnken experimental design, the research investigated the influence of layer thickness, wall perimeter and infill level on mechanical resistance through compression. Parameters such as maximum force, printing time and mass utilization are considered for assessing and enhancing mechanical properties.FindingsThe layer thickness was identified as the most influential parameter over the compression time, followed by the degree of infill. The number of surface layers significantly influences both maximum strength and total mass. Optimization strategies suggest reducing infill percentage while maintaining moderate to high values for surface layers and layer thickness, enabling the production of lightweight components with adequate mechanical strength and reduced printing time. Experimental validation confirms the effectiveness of these strategies, with generated regression equations serving as a valuable predictive tool for similar parameters.Practical implicationsThis research offers valuable insights for industries using 3D printing in creating prototypes and functional parts. By identifying optimal parameters such as layer thickness, surface layers and infill levels, the study helps manufacturers achieve stronger, lighter and more cost-efficient components. For industrial and engineering applications, adopting the outlined optimization strategies can result in components with enhanced mechanical strength and durability, while also reducing material costs and printing times. Practitioners can use the developed regression equations as predictive tools to fine-tune their production processes and achieve desired mechanical properties more effectively.Originality/valueThis research contributes to the ongoing evolution of additive manufacturing, providing insights into optimizing structural rigidity through polylactic acid (PLA) selection, Box−Behnken design and overall process optimization. These findings advance the understanding of fused deposition modeling (FDM) technology and offer practical implications for more efficient and economical 3D printing processes in industrial and engineering applications.