Limited Workability Research Articles

Tailoring Deformation Homogeneity of WE43 Alloy through Strain Rate Sensitivity and Back Pressure during Equal Channel Angular Pressing

AbstractEqual channel angular pressing (ECAP) of the magnesium alloys at room temperature owing to their limited workability is challenging. Successful ECAP processing of WE43 magnesium faces two main difficulties, heterogeneous distribution of the strain rate and also tensile strain accommodation on the top surface of the workpiece, leading to catastrophic segmentation of the alloy. In this paper, strain rate sensitivity (SRS) was studied to adopt a proper preprocessing of the material before ECAP processing. The SRS exponents, obtained from compression tests, revealed that solution treatment reduced the SRS of the alloy. To mitigate strain accommodation, an ECAP core-sheath configuration was used to induce back pressure for the sake of deformation homogeneity improvement. A combination of experimental processing and 3D finite element method simulations was applied to the solution-treated WE43 alloy with different core sizes and sheath materials. By finding the optimized core sizes and sheath materials with higher strengths, the differences in microhardness and equivalent plastic strain were reduced. Besides, the adequate magnitude of back pressure and the imposed fully compressive stress prevent fragmentation of the WE43 core during ECAP. After stepwise modifications, the plastic strain inhomogeneity index decreased from 1.340 to 0.671.

Self-employed workers with chronic health conditions: A qualitative study.

Chronic health conditions affect many individuals of working age, who cope with physical, psychological, and social difficulties that often involve limited work ability. This qualitative study explored experiences of self-employed individuals with chronic health conditions to advance our understanding of the effect of chronic illness on work. In-depth semi-structured interviews were conducted with 23 self-employed individuals coping with cancer, heart disease, inflammatory bowel disease, lung disease, or asthma. Data were analyzed with thematic analysis. Analysis of the interviews revealed four themes: uncertainty in planning work and committing to customers, acceptance versus denial of reduced work abilities, disclosure of health status to workers and customers, and temporal substitutes as a source of both support and concern. The results indicate that self-employed workers with a chronic health condition cope with unique challenges due to the need to sustain their business in the face of illness and a sense of sole responsibility.

P041 Living with foot and ankle disorders in rheumatic and musculoskeletal diseases: a thematic synthesis of qualitative studies to inform the work of the Outcome Measures in Rheumatology (OMERACT) Foot and Ankle Working Group

Abstract Background/Aims Foot and ankle involvement is common in rheumatic and musculoskeletal diseases (RMDs), but high-quality evidence is lacking to determine the effectiveness of foot and ankle treatments. Heterogeneity in the outcomes used across clinical trials in this area hinders the ability to compare study findings, and some outcomes are not always meaningful to patients. This study aimed to determine what outcomes are important to patients by exploring and synthesising qualitative data relating to the symptoms and impact of living with foot and ankle disorders in RMDs. Methods Six databases (CINAHL; Ovid Embase; Ovid MEDLINE; Psycinfo; Cochrane Database of Systematic Reviews; CENTRAL) were searched from inception to March 2022. Qualitative interview or focus group studies published in English and involving participants living with foot or ankle disorders in RMDs (inflammatory arthritis, osteoarthritis, crystal arthropathies, connective tissue diseases, and musculoskeletal conditions in the absence of systemic disease) were included. Quality was assessed using the Critical Appraisal Skills Programme qualitative tool. All data from the results section of included studies were extracted, coded and synthesised to develop themes. Patient and public involvement contributors were involved throughout the review, from design of the study to interpretation of the results and discussions about the findings. Results Of 1,440 database records screened, 34 studies were included, with a total of 581 participants. Studies focused on living with foot or ankle disorders in rheumatoid arthritis (n = 18), osteoarthritis (n = 5), gout (n = 3), psoriatic arthritis (n = 1), lupus (n = 1), posterior tibial tendon dysfunction (n = 1), plantar heel pain (n = 1), Achilles tendonitis (n = 1), and mixed population (n = 3) patients. Six themes were generated from the thematic synthesis: pain, change in appearance, activity limitations, social isolation, limited work ability and emotional impact. Foot or ankle pain was the predominant symptom experienced by patients in all included studies and was closely linked to other themes. Both pain and change in appearance of the feet or ankles (deformity), and subsequent limitations in footwear and clothing choices, led to restrictions in physical activities, social participation and work. Emotional distress, including anxiety, anger and embarrassment, was common among patients with foot and ankle disorders across all of the RMDs explored in this review. Conclusion This is the first study to synthesise findings of qualitative research exploring the lived experience of patients with foot and ankle disorders in RMDs. Findings indicate that these disorders impact on multiple areas of patients’ lives, both physically and psychologically. Patients’ experiences of foot and ankle disorders are similar across different RMDs, although there are a limited number of qualitative studies focusing on conditions other than rheumatoid arthritis. These findings will inform a future consensus study prioritising the outcomes that should be measured in future research studies and clinical practice. Disclosure L.S. Chapman: None. C. Flurey: None. A.C. Redmond: None. P. Richards: None. C. Hofstetter: None. B. Tapster: None. J. Emmel: None. P.S. Helliwell: None. H.B. Menz: None. M.T. Hannan: None. B. Shea: None. H.J. Siddle: None.

Association of short poor work ability measure with increased mortality risk: a prospective multicohort study

ObjectivesTo examine whether a single-item measure of self-rated work ability predicts all-cause mortality in three large population-based samples collected in 1978–1980, 2000 and 2017.SettingA representative sample of the population of...

Latest research and developments of ceramic reinforced magnesium matrix composites—A comprehensive review

High-performance lightweight materials give rise to a demand for magnesium-based composites. Magnesium metal matrix composites have found extensive applications in the aerospace and automotive industries due to their remarkable mechanical properties. Limitations in dispersion, strength, and interface strength of magnesium-based composites are seen through the addition of some hybrid reinforcements and different fabrication techniques. In this regard, previous studies have demonstrated the ability of various reinforcements such as graphene, carbon nano tubes, silicon carbide, and titanium carbide to a magnesium matrix for the enhancement of its metallurgical properties. There are still several challenges in the development of magnesium metal matrix composites, such as non-homogeneous distribution, poor creep resistance at elevated temperatures, limited cold work ability, and low corrosion resistance. The challenges that need to be overcome and suggestion for improving the wear resistance and frictional properties of magnesium metal matrix composites were studied and discussed. This review evaluates the importance of different reinforcement percentages as well as the development of magnesium metal matrix composites. The different types of fabrication techniques that are well suited to overcome the challenges of poor dispersing, non-homogeneous distribution, interfacial problems, and poor wettability are discussed. Microstructure analysis, the agglomerating effect, and matrix bonding strength are also discussed. The challenges and future scope of research are discussed for the demonstration of the importance of more scientific studies in magnesium metal matrix composites.

A comprehensive diagnostic service to clarify intervention needs when work participation is at risk: study protocol of a randomized controlled trial (GIBI, DRKS00027577)

BackgroundEffective care services for people whose work participation is at risk require low-threshold access, a comprehensive diagnostic clarification of intervention needs, a connection to the workplace and job demands, and interdisciplinary collaboration between key stakeholders at the interface of rehabilitation and occupational medicine. We have developed a comprehensive diagnostic service to clarify intervention needs for employees with health restrictions and limited work ability: this service is initiated by occupational health physicians.Methods/designOur randomized controlled trial tests the effectiveness of a comprehensive diagnostic service for clarifying intervention needs (GIBI: Comprehensive clarification of the need for intervention for people whose work participation is at risk). The comprehensive intervention comprises three elements: initial consultation, two-day diagnostics at a rehabilitation center and follow-up consultations. We will include 210 employees with health restrictions and limited work ability, who are identified by occupational health physicians. All individuals will receive an initial consultation with their occupational health physician to discuss their health, work ability and job demands. After this, half the individuals are randomly assigned to the intervention group and the other half to the waiting-list control group. Individuals in the intervention group start two-day diagnostics, carried out by a multi-professional rehabilitation team in a rehabilitation center, shortly after the initial consultation. The diagnostics will allow first recommendations for improving work participation. The implementation of these recommendations is supported by an occupational health physician in four follow-up consultations. The control group will receive the comprehensive two-day diagnostic service and subsequent follow-up consultations six months after the initial consultation. The primary outcome of the randomized controlled trial is self-rated work ability assessed using the Work Ability Score (0 to 10 points) six months after study inclusion. Secondary outcomes include a range of patient-reported outcomes regarding physical and mental health, impairment, and the physical and mental demands of jobs.DiscussionThis randomized controlled trial is designed to test the effects of a new complex intervention involving a comprehensive clarification of intervention needs in order to promote work participation and prevent the worsening of health and work disability.Trial registrationGerman Clinical Trials Register (DRKS00027577, February 01, 2022).

Changes in healthy and unhealthy working life expectancies among older working-age people in Finland, 2000–2017

BackgroundRaising the statutory retirement age has been a common policy response to population ageing, but health problems may restrict labour force participation in older ages. We examined the development of healthy and unhealthy working life expectancies in Finland from 2000 to 2017 using different measures of health problems.MethodsHealthy and unhealthy working life expectancies were calculated for the age range 50–65 years using the Sullivan method. The health measures were limiting long-standing illness, self-rated health, mental health problems and self-assessed work ability.ResultsHealthy working life expectancy was highest when health was measured by work ability. From 2000 to 2017, working years in full ability between the ages 50–65 increased from 6.2 (95% confidence interval 5.9–6.4) to 8.2 (8.0–8.5). Healthy working life expectancy increased also when measured by the other indicators. Unhealthy working years also increased, except when health problems were measured by limiting long-standing illness. The share of years in work increased both within the healthy and the unhealthy years, the increase being larger or equally large for the latter. Within the healthy and unhealthy years measured by the other three indicators, the share of working years increased irrespective of whether work ability was full or limited, but the increase was larger for limited work ability.ConclusionsIn Finland, healthy working life expectancy has increased irrespective of how health is measured but also working with health problems has become more prevalent. The estimates for healthy working years are highest when a direct measure of work ability is used.

Effect of Rolling Orientation on the Microstructure and Mechanical Properties of AZ31B Mg Alloy

The magnesium AZ31B alloy has been utilized in a variety of applications within the automotive and aviation industries due to its high specific strength, low-cost processing, and low density. However, the AZ31B alloy generally has poor ductility and limited workability at room temperature. The objective of this study was to develop a manufacturing processing technique to increase the potential uses of this alloy. The methodology includes cold rolling and annealing using small pass reductions until the samples reached a final thickness of 1.78 mm (0.07 in). The samples were cut into 10.16 mm (0.4 in), 7.62 mm (0.3 in), and 5.08 mm (0.2 in) thicknesses prior to cold rolling and were rolled in 0-, 45-, and 90-degree rolling directions. The grain shapes and sizes were examined via optical microscopy. Tensile testing was conducted to determine the strength and ductility. Scanning electron microscopy (SEM) images were taken to evaluate fractured surfaces. All processes including rolling direction and furnace cooling or air cooling after annealing produced similar results of medium strength (245-250 MPa in ultimate strength, 122-127 MPa in yield) and greater than 22.5% elongations in very thin sheets. Samples rolled along the 45-degree direction produced the highest percent reduction in thickness.

Strengthening of aluminium alloy 7005 through imposition of severe plastic deformation supplemented by different ageing treatments

Strengthening of aluminium alloys 7xxx through the imposition of severe plastic deformation supplemented by ageing treatments is a challenge due to the limited workability of these alloys in cold deformation regimes. This study aims to comprehensively investigate the strengthening of aluminium alloy 7005 through the imposition of severe plastic deformation supplemented by two different ageing treatments: pre-deformation artificial ageing or post- deformation natural ageing. For this purpose, microstructure evolutions of the alloy processed through mentioned procedures were studied using X-ray diffraction and scanning electron microscopy while the alloy strengthening was evaluated using Vickers hardness measurement. Results show that a superlative strengthening is obtained through the imposition of severe plastic deformation supplemented by post-deformation natural ageing. For instance, the yield strength of the alloy increases to more than 400 MPa, about one-third greater than the counterpart amount after the usual T6 treatment. This superlative strength mainly occurs due to refinement of grains, an increase of dislocation density and an increase of volume fraction of the precipitates that appeared during natural ageing. Considering the applied models, it is inferred that the increase of volume fraction of precipitates that appeared during natural ageing has a determinative role in the strengthening of the alloy.

Reinforced Composite Polymer in Automotive Industry : A Review

Modern era is witnessing tremendous move on in discipline of Science and technology. Near has been provocation of notice in Reinforced Composite Polymer (RPC’s) in a range of regime of technology. Broad study is want of hour in line of work of composite fibers anticipated to innovation of new technology and necessitate of advance accomplishment from open material. RPC’s are emerging environment pleasant materials as they container be recycled thermally without posing any menace to environment and originates from renewable sources. They have become a viable alternatives to existing employed carbon fibers polymers having disastrous effect on environment and having limited workability as well as cumbersome disposal. RPC’s have remarkable properties of impact toughness and Fatigue Strength. This is due to their partial brittle structure comprising of ductile and tough matrix interfolded with strong as well as brittle binder. RPC’s have encompassed almost every sphere of automobile industry and are widely used in interior parts, bonnets design and fabrication of accessories as well as in providing insulation platform in automobiles.

The role of depression and other psychological factors in work ability among breast cancer survivors in Australia.

Identifying modifiable factors affecting work ability among cancer survivors is important. The primary aim of the present study was to examine the effects of depression and related psychological factors on work ability among breast cancer survivors in Australia. In this cross-sectional electronic and postal survey, Australian breast cancer survivors were investigated. Work status and conditions before and after cancer treatment were analysed. Work ability was measured using the Work Limitation Questionnaire©-Short Form (WLQ-SF) with its four domains (time management, physical tasks, mental-interpersonal tasks, and output tasks). Three psychological factors were investigated: depression, fear of cancer recurrence, and demoralisation. Sociodemographic and clinical data were also collected. Multivariate regression analysis was used to identify the associations of psychological factors with WLQ-SF. Among eligible survivors, 310 (50%) responded to the survey and were analysed. Nearly one third reported their work conditions had changed after cancer treatment. The depressed group reported limited work ability in 35%-44% of the four domains of WLQ-SF, while the non-depressed group reported limited work ability in only 8%-13%. At-work productivity loss was approximately fourfold higher in the depressed group than in the non-depressed group. In multivariate analysis, at-work productivity loss was associated with depression, demoralisation, and past history of anxiety. After breast cancer treatment, work conditions changed toward lower wages and working hours. Depression, demoralisation, and past history of anxiety were associated with lower work ability. Further evaluations of work rehabilitation in breast cancer survivors are warranted.

Development of a heat treatment strategy for the γ-TiAl based alloy TNM-B1 to increase the hot workability

Currently, TiAl turbine blades produced by isothermal forging are commercially used in aircraft jet engines. The limited workability of the HIPed microstructure causes long processing times because of low ram speeds and excessive wear on the costly molybdenum tools due to high forging stresses and temperatures. By introducing a multi-step heat treatment into the industrial forging chain, the formability of the material can be improved, leading to lowered production costs. In this work, the parameters of interest for improved formability are increased β/β0 phase fractions, increased cellular phase fractions and reduced proportions of lamellar colonies. Several two-step heat treatments were investigated. The parameters of interest were then measured and compared. Subsequently, compression tests were carried out for the most promising heat treatments. It could be shown that a flow stress reduction of around 10% can be achieved by one of these heat treatments (1300 °C/1 h/AC + 1100 °C/5 h/AC). For this heat treatment, reproducibility was also checked using differential scanning calorimetry.

Dynamic precipitation and dynamic recrystallization during hot deformation of a solutionized WE43 magnesium alloy

A solutionized wrought WE43 magnesium alloy was deformed through compression tests at a wide temperature range of 225–525 °C to study the possible interplay of dynamic recrystallization and precipitation. Deformation behavior of the experimental alloy as well as the microstructural evolutions at different temperatures were investigated. The results implied that limited workability of the experimental alloy at low temperatures may be, partly, ascribed to the segregation of Zr atoms and formation of Zr-rich precipitates. Dynamic recrystallization was occurred at 375 and 525 °C as the dominant microstructural mechanism. While, dynamic precipitation of β phase was prevalent at 450 °C, resulting in a flow softening in stress-strain curve. The interplay of dynamic precipitation and recrystallization at 450 °C was discussed. A time-temperature-transformation diagram was proposed for the occurrence of dynamic precipitation and recrystallization during deformation. The dynamic recrystallization mechanism was recognized to be bulging of prior grain boundaries at 345 and 525 °C, while it was replaced by continuous recrystallization and particle stimulated nucleation at 450 °C.

A longitudinal observational study of back pain incidence, risk factors and occupational physical activity in Swedish marine trainees

ObjectivesTo evaluate the occurrence of low back pain (LBP) and LBP that limits work ability, to identify their potential early risks and to quantify occupational physical activity in Swedish Armed...

Hot deformation behavior of a spark plasma sintered Fe-25Al-1.5Ta alloy with strengthening Laves phase

Intermetallic iron aluminide alloys show various advantages such as low material cost and a good creep resistance that is superior to the P92 martensitic-ferritic steel at 650 °C, nominating them as potential candidates for steam turbine applications. However, cast preforms for hot forging show a rather coarse microstructure and limited workability. Recent research thus introduced Fe-25Al-Ta alloys, where tantalum prevents excessive grain growth during solidification. This paper, for the first time, investigates the possibility of producing the Fe-25Al-1.5Ta (at.%) alloy by spark plasma sintering (SPS) from pre-alloyed powder particles and investigates its deformation behavior under compression in the temperature range of 900–1100 °C using the concept of processing maps. SPS is mainly used to analyze the possibility of inheriting the size of the initial powder particles into the sintered material.The SPSed specimen at room temperature reveals a homogeneous equiaxed microstructure consisting of fine A2-phase grains with an average size of 7 μm surrounded by the ternary (Fe, Al)2Ta, C14, Laves phase particles. Laves phase particles are precipitated predominantly on grain boundaries of the Fe-Al matrix grains. Several particles are also dispersed inside the grains.The presence of a fine-grained equiaxed microstructure at hot working temperature seems to improve workability and leads to a wide processing window. The optimum processing domain for the studied Fe-25Al-1.5Ta alloy locates at 1050–1100 °C/0.0013–0.01 s−1 with a power efficiency of 40–50%, where the material undergoes dynamic recrystallization. At low temperature and high strain rates, dynamic recovery is the major softening mechanism observed for the samples, where the efficiency of power dissipation reaches around 40%.The current study offers a possibility to produce a homogeneous fine-grained Fe-25Al-1.5Ta alloy strengthened by dispersed Laves phase particles using SPS compared to the coarse and columnar microstructure commonly obtained by casting. Such a refined microstructure leads to a good hot forgeability.

Equal channel angular pressing of spheroidal graphite cast iron

Spheroidal graphite cast iron is an engineering material which has proved its importance during previous decades. However, limited workability of this material could be a challenge for spreading of its applications and there is a little knowledge about severe straining of this material at warm and/or cold regimes. This work is conducted to examine imposition of a well-known severe plastic deformation process called equal channel angular pressing on this material through a warm deformation regime. For this purpose, a casing procedure combined with an pre-annealing treatment is applied to increase the workability of this material. Results show that an equivalent plastic strain as great as 0.9 can be successfully imposed on the spheroidal graphite cast iron at a temperature lower than half of the melting temperature of iron while no evidence from dynamic recrystallization of the ferrite phase is traced. This enhanced warm workability of SG cast iron is related to imposition of a compressive stress state as well as decrease of pearlite fraction by the pre-annealing.

Towards Damage Controlled Hot Forming

Metal forming processes may induce internal damage in the form of voids in the workpiece under unfavorable deformation conditions. Controlling the amount of damage induced by metal forming operations may increase service performance of the produced parts. Damage is crucial in high-performance components of limited workability such as jet engine turbine blades. Recent developments have introduced forged titanium aluminides into commercial jet engines. Titanium aluminides are lightweight intermetallic compounds with excellent creep properties but very limited ductility. Their low workability requires isothermal forging at slow strain rates, which is typically kept constant in the process. This work explores the possibility of increasing the ram speed during the process so that the process time is reduced while the amount of damage introduced into the workpiece is controlled. The results show that a 25% reduction in process time seems viable without increase in damage by solving an optimal control problem, in which the ram speed profile is determined off-line by minimization.

Connected Process Design for Hot Working of a Creep-Resistant Mg–4Al–2Ba–2Ca Alloy (ABaX422)

With a view to design connected processing steps for the manufacturing of components, the hot working behavior of the ABaX422 alloy has been characterized for the as-cast and extruded conditions. In the as-cast condition, the alloy has a limited workability, due to the presence of a large volume of intermetallic phases at the grain boundaries, and is not suitable to process at high speeds. A connected processing step has been designed on the basis of the results of the processing map for the as-cast alloy, and this step involves the extrusion of the cast billet to obtain a 12 mm diameter rod product at a billet temperature of 390 °C and at a ram speed of 1 mm s−1. The microstructure of the extruded rod has a finer grain size, with redistributed fine particles of the intermetallic phases. The processing map of the extruded rod exhibited two new domains, and the one in the temperature range 360–420 °C and strain rate range 0.2–10 s−1 is useful for manufacturing at high speeds, while the lower temperature develops a finer grain size in the product to improve the room temperature strength and ductility. The area of the flow instability is also reduced by the extrusion step, widening the workability window.

Assessment of work ability in competing strands of social insurance: the German case

The article describes the system of social security in the case of incapacity in Germany and analyses how the pathway into incapacity benefits is structured. A special focus of the article is on conditionality as it is applied in different systems of social security in Germany today. A main result of the analysis is that incapacity benefits are embedded into a chain of different benefits and social services for persons with limited work ability. For the German case, this leads to a defensive reaction from both the Public Employment Service and pension insurers.

Microstructure and mechanical properties of two binary Al‐Mg alloys deformed using equal channel angular pressing

AbstractIn the present work, the effect of severe plastic deformation (SPD) on the mechanical properties of two binary Al−Mg alloys have been investigated. Because of the limited workability of the investigated material, both alloys were subjected to the heat treatment (precipitation treatment) before plastic deformation using equal channel angular pressing (ECAP). Results of investigation show that the increased magnesium content result in a decrease in workability, however, the heat treatment improves ability for plastic working. It was also observed that a combination of heat treatment with severe plastic deformation causes an increase in mechanical properties when compared to the initial material. In order to characterize structural changes that occur after plastic deformation, scanning electron microscopy and transmission electron microscopy were used.