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The purpose of this study is to verify how the carbon doping of the WC-Co cemented carbide (CC) affected their structure before their processing by hot isostatic pressing (HIP) technology.

The samples for this experiment were fabricated by selective laser melting technology (SLM) using a YAG fiber laser with a power of P = 40 W and a scanning speed of 83 mm/s. The subsequent carbon doping process was performed in a chamber furnace at 900 0 C for 1, 4 and 12 h. The HIP was performed at 1,390°C and pressures of 40 MPa, 80 MPa and 120 MPa. The changes induced in the structures were evaluated using X-ray diffraction and various microscopic methods.

X-ray diffraction analysis showed that the structure of the samples after SLM consisted of WC, W₂C, Co₄W₂C and Co phases. As a result of the increase in the carbon content in the structure of the samples, the transition carbide W₂C and structural phase Co₄W₂C decayed. Their decay was manifested by the coarsening of the minor alpha phase (WC), which occurred both during the carburizing process and during the subsequent processing using HIP. In the samples in which the structure was carburized prior to HIP, only the structural phases WC and Co were observed in most cases.

The results confirm that it is possible to increase the homogeneity of the CC structure and thus its applicability in practice by additional carburization of the sample structure with subsequent processing by HIP technology.

This study aims to provide a comprehensive overview of the current state of the art in powder bed fusion (PBF) techniques for additive manufacturing of multiple materials. It reviews the emerging technologies in PBF multimaterial printing and summarizes the latest simulation approaches for modeling them. The topic of “multimaterial PBF techniques” is still very new, undeveloped, and of interest to academia and industry on many levels.

This is a review paper. The study approach was to carefully search for and investigate notable works and peer-reviewed publications concerning multimaterial three-dimensional printing using PBF techniques. The current methodologies, as well as their advantages and disadvantages, are cross-compared through a systematic review.

The results show that the development of multimaterial PBF techniques is still in its infancy as many fundamental “research” questions have yet to be addressed before production. Experimentation has many limitations and is costly; therefore, modeling and simulation can be very helpful and is, of course, possible; however, it is heavily dependent on the material data and computational power, so it needs further development in future studies.

This work investigates the multimaterial PBF techniques and discusses the novel printing methods with practical examples. Our literature survey revealed that the number of accounts on the predictive modeling of stresses and optimizing laser scan strategies in multimaterial PBF is low with a (very) limited range of applications. To facilitate future developments in this direction, the key information of the simulation efforts and the state-of-the-art computational models of multimaterial PBF are provided.

This study compares the fatigue performance and biocompatibility of as-built and chemically etched Ti-6Al-4V alloys in TPMS-gyroid and stochastic structures fabricated via Powder Bed Fusion Laser Beam (PBF-LB). This study aims to understand how complex lattice structures and post-manufacturing treatment, particularly chemical etching, affect the mechanical properties, surface morphology, fatigue resistance and biocompatibility of these metamaterials for biomedical applications.

Selective Laser Melting (SLM) technology was used to fabricate TPMS-gyroid and Voronoi stochastic designs with three different relative densities (0.2, 0.3 and 0.4) in Ti-6Al-4V ELI alloy. The as-built samples underwent a chemical etching process to enhance surface quality. Mechanical characterization included static compression and dynamic fatigue testing, complemented by scanning electron microscopy (SEM) for surface and failure analysis. The biocompatibility of the samples was assessed through in-vitro cell viability assays using the Alamar Blue assay and cell proliferation studies.

Chemical etching significantly improves the surface morphology, mechanical properties and fatigue resistance of both TPMS-gyroid and stochastic structures. Gyroid structures demonstrated superior mechanical performance and fatigue resistance compared to stochastic structures, with etching providing more pronounced benefits in these aspects. In-vitro biocompatibility tests showed high cytocompatibility for both as-built and etched samples, with etched samples exhibiting notably improved cell viability. The study also highlights the importance of design and post-processing in optimizing the performance of Ti64 components for biomedical applications.

The comparative analysis between as-built and etched conditions, alongside considering different lattice designs, provides valuable information for developing advanced biomedical implants. The demonstration of enhanced fatigue resistance and biocompatibility through etching adds significant value to the field of additive manufacturing, suggesting new avenues for designing and post-processing implantable devices.

In the last few decades, the growth in management institutions in India has become significant. The Open and Distance Learning (ODL) institutions also have started offering management programmes at various levels. In the ODL scenario, the learning path has been shifting from the traditional Self-Learning Material (SLM) -based model to technology-mediated platform. The digital divide in India is also a widely discussed area. In this context, a need has been felt to understand the implications for educators, more specifically, for the programmes offered through technology-enabled ODL mode.

This study uses triangulation method covering literature review, personal interview and survey. Primary data have been collected through structured questionnaire in the Google Form administered on the learners of UG and PG progammes of management in Krishna Kanta Handiqui State Open University (KKHSOU), India. The sample size is 101, and the sampling frame is within Assam, a province of India. Select interviews (15 nos.) were also conducted with a cross section of learners to capture the emerging shift in the learning path and the limiting factors of digital divide.

Learners possess multiple digital devices for e-learning (41.8% uses laptop and 88.8% uses android phone). Interaction in WhatsApp and Telegram groups are mostly related with evaluation and course administration, rather than content and academic discussion. eSLMs are widely used. Though promoted, video lectures are not widely used. Some of the problems faced by the learners are low bandwidth, high cost of data subscription etc. Learners are not constrained by digital device, and they are engaged in positive communication with stake holders in digital platform.

This study will help in understanding the technology-enabled learning for management education in ODL mode in India. As a wide majority of the learners (88%) are dependent on small screen; print SLM and eSLM on a larger screen can provide augmented learning in case of complex topics like analysis of financial statements, project scheduling etc. Though the COVID-19 pandemic forced a shift in learning path, the transition is not full. The digitally constrained learners still look for solutions to complex learning problems mainly through print SLM and counselling. The talent of the students cannot be facilitated in WhatsApp and Telegram e-mentoring groups, like the way it could be done in learning management system (LMS)-mediated platforms.

As an advanced manufacturing method, additive manufacturing (AM) technology provides new possibilities for efficient production and design of parts. However, with the continuous expansion of the application of AM materials, subtractive processing has become one of the necessary steps to improve the accuracy and performance of parts. In this paper, the processing process of AM materials is discussed in depth, and the surface integrity problem caused by it is discussed.

Firstly, we listed and analyzed the characterization parameters of metal surface integrity and its influence on the performance of parts and then introduced the application of integrated processing of metal adding and subtracting materials and the influence of different processing forms on the surface integrity of parts. The surface of the trial-cut material is detected and analyzed, and the surface of the integrated processing of adding and subtracting materials is compared with that of the pure processing of reducing materials, so that the corresponding conclusions are obtained.

In this process, we also found some surface integrity problems, such as knife marks, residual stress and thermal effects. These problems may have a potential negative impact on the performance of the final parts. In processing, we can try to use other integrated processing technologies of adding and subtracting materials, try to combine various integrated processing technologies of adding and subtracting materials, or consider exploring more efficient AM technology to improve processing efficiency. We can also consider adopting production process optimization measures to reduce the processing cost of adding and subtracting materials.

With the gradual improvement of the requirements for the surface quality of parts in the production process and the in-depth implementation of sustainable manufacturing, the demand for integrated processing of metal addition and subtraction materials is likely to continue to grow in the future. By deeply understanding and studying the problems of material reduction and surface integrity of AM materials, we can better meet the challenges in the manufacturing process and improve the quality and performance of parts. This research is very important for promoting the development of manufacturing technology and achieving success in practical application.

This paper aims to present an investigation into the variation of scan vector hatch rotation strategies in selective laser melting (SLM), focussing on how it effects density, surface roughness, tensile strength and residual stress.

First the optimum angle of hatch vector rotation is proposed by analysing the effect of different increment angles on distribution of scan vectors. Sectioning methods are then used to determine the effect that the chosen strategies have on the density of the parts. The top surface roughness was analysed using optical metrology, and the tensile properties were determined using uni-axial tensile testing. Finally, a novel multi-support deflection geometry was used to quantify the effects of rotation angles on residual stress.

The results of this research showed that the hatch rotation angle had little effect on the density, top surface roughness and strength of the parts. The greatest residual stress deflection was measured parallel to unidirectional scan vectors. The use of hatch rotations other than alternating 90° showed little benefit in lowering the magnitude of residual stresses. However, the use of rotation angles with a good suitability measure distributes stresses in all directions more evenly for certain part geometries.

All samples produced in this work were made from commercially pure titanium, therefore care must be taken when applying these results to other materials.

This paper serves to increase the understanding of SLM scanning strategies and their effect on the properties of the material.

This research addresses the professional logics of street-level managers (SLMs) and bureaucrats (SLBs) working in the Brazilian National Social Security Agency (INSS) through their perceptions of distributive justice and discretion. Since SLMs have the authority to influence SLBs' actions, we investigate whether these two groups hold similar viewpoints.

We integrate the administrative data and survey responses (n = 678) with earlier thematic content analysis (n = 350) in three stages: mean-testing, regression analyses and complementary qualitative analysis, integrated through a mixed-methods matrix.

Whilst no significant differences emerge in distributive justice ideas between groups, SLMs demand wider benefit-granting discretion, praising professionalism whilst adopting managerial posture and jargon.

The study adds to the theoretical discussions concerning SLM’s influence on SLB’s decision-making, suggesting that other factors outweigh it. The finding concerning the managers’ demand for wider discretion asks for further in-depth approaches.

Findings supply valuable insights for policymakers and managers steering administrative reforms, by questioning whether some roles SLMs play are limited to symbolic levels. Further, SLBs’ heterogenous formations might be more relevant to policy divergence than managerial influence and perhaps an underutilised source of innovation.

By approaching street-level management professional logics within a Global South welfare state through a mixed-methods approach, this study offers a holistic understanding of complex dynamics, providing novel insights for public sector management.

This paper seeks to ascertain the effectiveness of a two-week-long faculty development programme (FDP), organized by Indira Gandhi National Open University (IGNOU), for teachers of the open and distance learning (ODL) system, with the aim of upgrading their knowledge and skills for developing print self-learning materials (SLMs). The specific aim of this study is to ascertain whether the objectives of the FDP have been achieved, to examine the effectiveness of the training programme and to suggest measures for improvement in future FDPs regarding the design and development of print SLMs.

The study was conducted using a descriptive survey research method, through semi-structured questionnaires and adopted purposive sampling. The first survey was conducted immediately after the completion of the programme, in order to collect feedback from the trainees, while the second survey was conducted after six months of the FDP, using the follow-up approach, so that more reliable and authentic results could be obtained.

The outcomes of the study revealed that the training had been effective in imparting appropriate knowledge and skills to the trainees, with respect to designing print SLMs. However, certain gaps were also identified and have been reported in this paper. Key suggestions have been made to address the shortcomings and improve forthcoming FDPs.

The present research focused on a specific training programme regarding the design and development of SLMs. Therefore, only the teachers and academics who participated in this specialized training activity were considered for the collection of feedback.

The recommendations of this work may be useful for the trainers, FDP coordinators, training institutions and ODL policymakers for planning and designing effective staff development activities for teachers and academics working in ODL institutions. These would be especially useful in the design of FDPs, aimed at orienting teachers who are involved in curriculum planning, design and development of learning resources.

This study is an original research based on the empirical primary data obtained by the researchers. As the largest open university in the world, IGNOU has been playing a key role in staff development for and in ODL in developing countries. This evaluative study of a specialized FDP in the area of SLM design and development is a significant work that may be valuable for planning the staff development strategies and building a training evaluation mechanism.