Joining of dissimilar alloys Ti-6Al-4V and Ti-6Al-2Sn-4Zr-2Mo-0.1Si using linear friction welding

Dissimilar joints between Ti-6Al-4V (Ti-64) and Ti-6Al-2Sn-4Zr-2Mo-0.1Si (Ti-6242) were manufactured using linear friction welding. The weld quality, in terms of the microstructure and mechanical properties, was investigated after stress relief annealing (SRA) at 750 °C for 2 h and compared with the as-welded (AWed) results. The central weld zone (CWZ) microstructure in the AWed condition consisted of recrystallized prior-β grains with α' martensite, which transformed into an acicular α+β structure after SRA. The hardness in the AWed condition was highest in the CWZ and decreased sharply through the thermomechanically affected zones (TMAZ) to the parent materials (PMs). After SRA, the hardness of the CWZ decreased, mainly due to tempering of the α' martensite microstructure. Static tensile testing of the dissimilar welds in both the AWed and stress relief annealed (SRAed) conditions resulted in ductile fracture occurring exclusively in the Ti-6Al-4V side of the joint. The promising results on joining of Ti-64 to Ti-6242 provide valuable insight for tailoring performance of next-generation aero-engine products

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Outcomes of open pelvic fractures: A case series

Introduction: Albeit rare, open pelvic fractures are life threatening injuries associated with significant morbidity and mortality. Due to their rarity, there is paucity of data and literature on best management practices. An open pelvic fracture is one where there is a connection between the fracture site and either the skin, rectum, vagina, or genitourinary system. They commonly affect young individuals involved in high energy injuries. During resuscitation, prompt recognition and control of sepsis and stabilization of unstable fractures should precede definitive management. Materials and methods: We conducted a retrospective study of prospectively collected data between 2012 and 2022 for patients managed in two teaching hospitals in Kenya. All patients were followed up for at least 6 months. The Faringer classification was used to classify the soft tissue wounds and the Young and Burgess classification was used to classify the pelvic fractures. We investigated their functional outcomes using their ability to ambulate independently and the Merle d' Aubigne-Postel score. Results: Eight patients with an average age of 31 years were included. All were referrals. Three (37.5 %) developed sepsis but resolved. Four (50 %) needed a diverting stoma, which included 2 of the 3 patients who had developed sepsis. 5(62.5 %) needed an external fixator as part of definitive management. There were no mortalities. All achieved full independent ambulation; and all our patients achieved an average Merle d' Aubigne-Postel score of 17. Conclusion: Our study demonstrates that early sepsis control, appropriate fracture fixation and a multidisciplinary approach can yield satisfactory functional outcomes

Shear punch test for strength and ductility measurements of Ti-6%Al-4%V-TiC particulate reinforced MMC's

Peer reviewed: YesNRC publication: N

Effect of carbon content on dynamic recrystallization behaviour of plain carbon steels

The occurrence of dynamic recrystallization in hypoeutectoid and hypereutectoid steels of 0.7 and 0.9% carbon was investigated under isothermal conditions. Compression tests were performed using single deformation schedules at temperatures between 900 and 1050 \ub0C and strain rates of 0.01s-1, 0.1s-1 and 1s-1. It was observed that the activation energy for deformation decreased with increasing carbon content in the steels. The peak and steady state strain values determined from the flow curves generated by hot compression deformation were used to examine the possible evolution of grain size by recrystallization.a recristallisation dynamique d\u2019aciers hypoeutecto\uefdes et hypereutecto\uefdes \ue0 0.7 et 0.9 % de carbone est \ue9tudi\ue9e. Des tests de compression sont effectu\ue9s dans des conditions isothermes \ue0 des temp\ue9ratures comprises entre 900 et 1050 oC et \ue0 des vitesses de d\ue9formation de 0.01 s-1, 0.1 s-1 et 1s-1. Il est observ\ue9 que l\u2019\ue9nergie d\u2019activation de d\ue9formation diminue lorsque le taux que carbone dans l\u2019acier augmente. Les valeurs de la d\ue9formation \ue0 la contrainte maximale et au d\ue9but de l\u2019\ue9tat stationnaire, d\ue9termin\ue9es \ue0 partir des courbes d\u2019\ue9coulement g\ue9n\ue9r\ue9es par la d\ue9formation \ue0 chaud, sont utilis\ue9es pour \ue9tudier l\u2019\ue9volution possible de la taille des grains par recristallisation.Peer reviewed: YesNRC publication: Ye

Measurement of pearlite interlamellar spacing in hypereutectoid steels

In hypereutectoid steels, determination of interlamellar spacing is essential to microstructural characterization, since both static and dynamic properties have been related to the pearlitic structure. Generally, quantitative analysis of the size of a pearlite colony and its interlamellar spacing is performed using optical and electron microscopy techniques. In this work, laser scanning confocal and field emission scanning electron microscopes were used to examine interlamellar spacing in isothermally transformed hypereutectoid steels to benefit from increased resolving power and statistical significance capabilities as compared to light optical and transmission electron microscopes, respectively.NRC publication: Ye

Continuous Cooling Transformation Temperature and Microstructures of Microalloyed Hypereutectoid Steels

The transformation behavior under continuous cooling conditions was investigated for four hypereutectoid steels of 1% carbon with different microalloying additions of vanadium and silicon. Continuous cooling compression testing of the hypereutectoid steels was employed to study the influence of processing conditions (re-heat temperature), microstructure (prior-austenite grain size) and chemical composition (vanadium and silicon) on the critical transformation temperature (Ar3). Overall, for the hypereutectoid steel compositions examined, the transformation temperatures were determined to be relatively stable, with a variation of roughly 15\ub0C when the reheat temperature was changed from 1000 to 1200\ub0C. The addition of microalloying elements such as vanadium and silicon was determined to increase the austenite-to-pearlite transformation start temperature of the hypereutectoid steels by about 10\u201330\ub0C. These changes in the transformation behavior observed with decreasing re-heating temperature and microalloying additions were related to microstructural changes in the hypereutectoid steels, such as prior-austenite grain size refinement, carbide precipitation and grain boundary cementite fragmentation.NRC publication: Ye

Laser welding of TA6V with filler additions to alleviate joint gap and effect of post weld heat treatments

Peer reviewed: YesNRC publication: Ye

Hot deformation processing of Ti-6%Al-4%V/TiC particulate reinforced composites

Peer reviewed: YesNRC publication: N