Vicarious Trauma Among Interpreters

Public service interpreters in Australia work in a range of areas including welfare, health, education and criminal justice. Some of their assignments contain traumatic client material, which may be confrontational, upsetting or off-putting for an interpreter, potentially impacting on their perceived cognitive processes and emotions during and after the interpreting assignment. Through a large-scale online survey of 271 practicing interpreters in Victoria, Australia, the authors explore the extent of exposure to traumatic client material, interpreters’ ways of coping with such material, and how institutional care and self-care are administered, if they are at all. The findings of the survey are presented in this article and the implications for public service interpreters are discussed from an occupational health and safety perspective. Limitations of the study and recommendations for future research are outlined

Laser machining of zirconia green compacts to produce cavities and blocks: parametric optimization and patterning

Zirconia is a very popular material among implants and prosthesis, due to its antibacterial activity, corrosion resistance and hardness properties. For these purposes, zirconia is to be sintered beforehand to obtain good dimensional and geometrical accuracy and then machined. However, the machining of sintered zirconia has always been a troublesome proposition, attributable to its extreme hardness. The excellent properties of zirconia were applied in this study to the cutlery design. Nowadays, cutlery/flatware designs are constantly changing. However, for manufacturing, the traditional molding process remains widely popular, despite having huge limitations regarding aesthetic and design flexibility. In the present study, we explore a new horizon of cutlery design by patterning using laser surface modification. Blocks were laser machined from zirconia green compacts, which solved the machining problems associated with sintered zirconia, and then inserted into stainless-steel cutlery grooves to produce a novel aesthetical cutlery design. This study addresses the parametric optimization of laser parameters (power, scanning speed and number of passages) to produce cavities in zirconia green compacts. Material removal, depth of cut, geometry and surface roughness were taken as output variables. For the analyses, a full factorial design of experiments was adopted. Moreover, this study provides the optimum parameters for the laser machining of zirconia green compacts to produce blocks with accurate dimensions and geometries. After laser machining the zirconia blocks, sintering was performed to achieve the desired dimensions.publishe

Laser surface texturing of stainless-steel cutlery to integrate ceramic blocks: parametric optimization and patterning

Dynamic and fast-changing designs for cutleries or flatware are one important nature of this production business. Globalized hospitality merchandise, the demanding nature of modern customers, throat-to-throat competition of manufacturing industries, and the modernization of the manufacturing processes are some of the major challenges for the cutlery (silverware) manufacturing industry. So far, traditional methods of moulding and shaping are considered to be the best to provide static designs and trademark patterns of the organisation. Preparing a designed mould for a fixed blueprint of cutlery and then producing it in bulk is the sole purpose of existing methods. However, with the invention of laser engraving and design systems, the entire business of cutlery production has revolutionized. Allowing for different designs for different cutleries to set without changing the whole production line was the aim of this study. As shown in Figure 1, AISI-304 stainless steel, which is the general flatware material selected for laser engraving, was evaluated with three most vital input parameters (power, scanning speed and loops or number of passes) followed by the analysis of geometry, roughness, and volume removed/material removal (MR) as output variables. This study will provide insight into the know-how situation involving the processing of cutleries and introduction of different ceramic materials to the surface to define desired patterns. We produced different design patterns by laser and ingrained ceramic blocks on the silverware. This approach is much more flexible and adoptable for pattern changes. Besides that, there is no need to prepare a mould for each design. Belo Inox, Portugal supplied the silverware as per the collaborative project agreement.publishe

Mechanical properties of Ti6Al4V fabricated by laser powder bed fusion: a review focused on the processing and microstructural parameters influence on the final properties

Ti6Al4V alloy is an ideal lightweight structural metal for a huge variety of engineering applications due to its distinguishing combination of high specific mechanical properties, excellent corrosion resistance and biocompatibility. In this review, the mechanical properties of selective laser-melted Ti6Al4V parts are addressed in detail, as well as the main processing and microstructural parameters that influence the final properties. Fundamental knowledge is provided by linking the microstructural features and the final mechanical properties of Ti6Al4V parts, including tensile strength, tensile strain, fatigue resistance, hardness and wear performance. A comparison between Laser Powder Bed Fusion and conventional processing routes is also addressed. The presence of defects in as-built Ti6Al4V parts and their influences on the mechanical performance are also critically discussed. The results available in the literature show that typical Laser Powder Bed–Fused Ti6Al4V tensile properties (>900 MPa yield strength and >1000 MPa tensile strength) are adequate when considering the minimum values of the standards for implants and for aerospace applications (e.g., ASTM F136–13; ASTM F1108–14; AMS4930; AMS6932).This work was supported by FCT national funds, under national support to an R&D units grant, through the reference projects UIDB/04436/2020 and UIDP/04436/2020 and also through the projects ADD2MECBIO (PTDC/EME-EME/1442/2020) and Additive_Manufacturing to Portuguese Industry_POCI-01-0247-FEDER-024533

Chip morphology evaluation on turning of 316L stainless steel using laser surface textured WC-Co cutting tools

Euro Powder Metallurgy 2023 Congress & Exhibition, 1 - 4 Outubro 2023. Lisboa, Portugal.During machining processes, a large amount of heat is generated, especially in the cutting zone, due to the deformation of the material and to the friction of the chip along the surface of the cutting tool, resulting in, a wear increase and consequent reduction of tool life. Surface texturing can help improve these tools tribological performance by increasing their load carrying capacity, providing a more efficient lubricant supply at the tool-chip interface and reducing the tool-chip contact area. In this context, the fabrication of cross-hatched micropatterns on WC-Co cutting tools by laser surface texturing of green compacts is proposed, aiming to improve these tools performance and life. This work is focused on evaluating the morphology of the chip obtained when turning 316L stainless steel with tools textured with different cross-hatched micropatterns, these findings being benchmarked against conventional cutting tools and correlated with the tool wear. For such purpose, morphological characterization using optical and scanning electron microscopy was used

Additive manufacturing of embedded thermocouples in WC-Co cutting tools for cutting temperature measurement

A publicar em PowderMet2023, 18 - 21 jun. 2023, Caesars Palace, Las Vegas, USADuring machining processes, a large amount of heat is generated due to deformation of the material and friction of the chip along the surface of the tool, especially in the cutting zone. This high temperature strongly influences tribological phenomena and adhesion, tool wear, tool life, workpiece surface integrity and quality, chip formation mechanisms and contribute to the thermal deformation of the cutting tool, leading to high operating costs and reduction of the end product quality. In this sense, being able to assess the cutting temperature in real time, at various points of the cutting tool during machining processes, is of utmost importance to effectively optimize cutting parameters and the cutting fluid flow adequately, for minimizing heat generation, temperature and consequently wear, allowing to increase tool life. This work proposes the fabrication of embedded additively manufactured type K and type N thermocouples by laser powder bed fusion for real time cutting temperature measurement. Processing parameters optimization was performed to obtain a dense and continuous thermocouple with no significant defects and the additively manufactured thermocouples were tested in comparison to a conventional thermocouple. The obtained results show that this approach is effective to produce embedded thermocouples in WC-Co cutting tools capable of measuring cutting temperature, which will allow a real time optimization of the cutting parameters, namely cutting speed, feed and depth of cut, during in-service time, thus enhancing tool performance and life.This work was supported by FCT (Fundação para a Ciência e a Tecnologia) through the grant 2020.07155.BD and by the project POCI-01-0145-FEDER-030353 (SMARTCUT) and PTDC/EMEEME/1442/2020 (Add2MechBio). Additionally, this work was supported by FCT national funds, under the national support to R&D units grant, through the reference projects UIDB/04436/2020 and UIDP/04436/2020. Finally, this work was also developed within the scope of the project CICECO-Aveiro Institute of Materials, UIDB/50011/2020, UIDP/50011/2020 & LA/P/0006/2020, financed by national funds through the FCT/MCTES (PIDDAC)

The influence of laser power and scan speed on the dimensional accuracy of Ti6Al4V thin-walled parts manufactured by selective laser melting

Laser Powder Bed Fusion (LPBF) technologies such as Selective Laser Melting (SLM) are being increasingly considered as viable production routes. This paradigm change demands an in-depth understanding of the fabrication process and variables, as previous studies have shown that energy density calculation alone is insufficient, because parts fabricated using similar energy density, but using different combinations of parameters, can display significantly different properties and dimensions. Thin-walled parts are particularly influenced by processing parameters; in this sense, this study explores the influence of laser power and scan speed on the dimensions of Ti6Al4V thin-walled tubes. Predictive models for manufacturing Ti6Al4V thin-walled tubes were developed using Response Surface Methodology (RSM), and the most influential (single and combined) factors were determined using Analysis of Variance (ANOVA). Three models were obtained: for the wall melt zone thickness, the total wall thickness, and the hole width.FCT (Fundação para a Ciência e a Tecnologia) through the project PTDC/EME-EME/1442/2020 (Add2MechBio) and POCI-01-0247-FEDER-024533 (Add-Additive–Add additive manufacturing to Portuguese industry). Acknowledgments to the project CICECO-Aveiro Institute of Materials, UIDB/50011/2020, UIDP/50011/2020, and LA/P/0006/2020, financed by national funds through the FCT/MEC (PIDDAC)

MgO nanoparticles obtained by Pulsed Laser Ablation in Liquid: a study on fabrication versatility aiming different applications

Apresentação efetuada em "Junior Euromat 2022", em Coimbra, 2022Nano and micro-sized metal particles are used in diverse fields, from electronics to biomedical. Among them, Magnesia, also known as magnesium oxide (MgO), is one of the most interesting metal oxides due to its unique properties, such as a large electrochemically active surface area and chemical stability. Although chemical routes such as chemical reactions, thermal evaporation,sol-gel, chemical vapor deposition and hydrothermal treatments are mainly used to fabricate metal oxide nanoparticles, they require the use of toxic reagents and long processing times. Thus, developing a simple green synthetic process for preparing MgO nanoparticles remains a challenging topic of investigation. Pulsed laser ablation in liquid (PLAL) has emerged as a potential alternative to chemical methods because it does not require chemicals, generates no waste, and produces high-purity particles. By changing some parameters such as the laser wavelength, laser fluence, and liquid media the size and shape of the particles produced can be tailored. The obtained particles can be added to act as anti-biofilm agents on coatings. Both influence of the liquid medium and the laser energy on nanoparticle composition and morphology are investigated in this work, as well as the effects of laser energy and different liquid media on the properties and characteristics of these nanoparticles.Acknowledgements: This work was supported by Fundação para a Ciência e Tecnologia through the grant 2020.07257.BD, the projects UIDB/04436/2020 and UIDP/04436/2020. PTDC/EME-EME/1442/2020(Add2MechBio). Additionally, this work was developed within the project CICECO-Aveiro Institute of Materials, UIDB/50011/2020, UIDP/50011/2020 & LA/P/0006/2020, financed by national funds through the FCT/MEC (PIDDAC)

The influence of surface finishing on laser heat treatments of a tool steel

Laser heat treatments (LHT) has received growing attention in the last years because of highly localized precision and manufacturing efficiency related to laser processing of moulds steel. Due of its strong resistance and ability to maintain hardness and strength at high temperatures, AISI P20 steel is one of the most widely used tool steel in the plastics injection mould industry. This work presents an experimental investigation on LHT using P20 mod. steel produced with different surface finishes. After mechanical surface finishing, the diode laser beam with 15 mm width was applied to the P20 specimens at 1060 °C using a feed rate of 8.8 mms-1in an air and argon ambient. The influence of different LHT atmosphere conditions and specimen initial surface finishing on characteristics such as final roughness, microhardness and microstructure were comprehensively analyzed. The use of a controlled atmosphere during processing showed an increment in depth and hardness values of samples. Through 3D profilometer, it was possible to determine the samples roughness. Results showed that lower average roughness leads to higher hardness values close to the surface, while higher average roughness lead to a deeper heat-treated zone. Macroscopical analysis revealed the depth and width afftected by LHT. The microhardness results showed an increment from 300 HV to around 750 HV on laser heat-treated zone using a controlled environment. Optical microscopy analysed the microstructural changes into martensite between LHT and non LHT zones for all samplespublishe

Selective laser melting of Ti6Al4V sub-millimetric cellular structures: prediction of dimensional deviations and mechanical performance

Ti6Al4V sub-millimetric cellular structures arise as promising solutions concerning the progress of conventional orthopedic implants due to its ability to address a combination of mechanical, physical and topological properties. Such ability can improve the interaction between implant materials and surrounding bone leading to longterm successful orthopedic implants. Selective Laser Melting (SLM) capability to produce high quality Ti6Al4V porous implants is in great demand towards orthopedic biomaterials. In this study, Ti6Al4V cellular structures were designed, modeled, SLM produced and characterized targeting orthopedic implants. For that purpose, a set of tools is proposed to overcome SLM limited accuracy to produce porous biomaterials with desired dimensions and mechanical properties. Morphological analyses were performed to evaluate the dimensional deviations noticed between the model CAD and the SLM produced structures. Tensile tests were carried out to estimate the elastic modulus of the Ti6Al4V cellular structures. The present work proposes a design methodology showing the linear correlations found for the dimensions, the porosity and the elastic modulus when comparing the model CAD designs with Ti6Al4V structures by SLM.This work was supported by FCT through the grant SFRH/BD/ 128657/2017 and the projects PTDC/EMS-TEC/5422/2014_ADAPT PROSTHESIS, NORTE-01-0145-FEDER-000018 – HAMaBICo and UID/ EEA/04436/2019