Sheet Metal Working Research Articles

APPRAISING FABRICATION AND WELDING STUDENTS’ EMPLOYABILITY SKILLS IN OGUN STATE TECHNICAL COLLEGES

This study appraised fabrication and welding students’ employability skills in Ogun State technical colleges. Two research questions were raised in relation to the focus of the study. A structured Questionnaire containing 15 items was developed and used for data collection. The questionnaire was validated by 3 experts and tested for reliability using Cronbach Alpha Coefficient at 0.96. The questionnaire was used for collecting data from 57 respondents made by fabrication and welding industrial-based supervisors in Ogun State. The data collected were analyzed using descriptive statistics of mean and standard deviation to answer the research questions raised in the study. The study affirmed that fabrication and welding students in Ogun State technical colleges possessed sheet metalwork skills and gas welding skills. The study recommended among others that adequate supervision and monitoring of TVET institution’s students on industrial attachment should be ensured by TVET institution’s administrators and that industrial-based supervisors should be objective in discharging their duties during students’ industrial attachment period.

Research on the Optimal Regime of Recrystallization in 1050 Aluminium Alloy

Abstract The development of technical applications required the use of many metals and alloys, other than steel and cast iron. Thus, non-ferous metals and alloys represent a category of materials of great technical importance, their application beeing determined by their properties. The mechanical properties of Al depend on its degree of purity as well as the plastic and thermal processing it was subjected to, being used either in metallic constructions due to its low density or for electrical conductors due to its ductility in the shape of sheets and strips, being malleable materials, or foils for packaging in the food industry. In this research, it is highlighted the influence of temperature and the time of maintenance on the mechanical properties and the microscopic structure of the recrystallized metal, namely the optimal recrystallization in 1050 aluminum alloy, a popular grade of aluminum for general sheet metal work where moderate strength is required.

Stepping Up to the Plate

Steed Webzell reviews the exhibits that are likely to have caught visitors’ eyes at sheet metalworking manufacturing technology show EuroBLECH 2018, which was attended by more than 55,000

Boosting Output

Two sheet metalworking companies have invested in automation, one in The Netherlands employs automation bought separately from its machines, while in the UK a package installation was the route taken

Continuing Innovation

Approaching a 200th-year milestone, sheet metalworking expert Group Rhodes has recently moved to an upgraded facility in Wakefield, only half a mile from where the business was founded in 1824. Andrew Allcock visited and discovers a modernised operation innovatively building on its deep capital goods roots (extended article: https://is.gd/akotuq )

Development of Product Availability Monitoring System In Production Unit In Automotive Component Industry

This paper described a methodology to monitor the availability of products in a production unit in the automotive component industry. Automotive components made are automotive components made through sheet metal working. Raw material coming into production unit in the form of pieces of plates that have a certain size. Raw materials that come stored in the warehouse. Data of raw each material in the warehouse are recorded and stored in a data base system. The material will then undergo several production processes in the production unit. When the material is taken from the warehouse, material data are also recorded and stored in a data base. The data recorded are the amount of material, material type, and date when the material is out of the warehouse. The material coming out of the warehouse is labeled with information related to the production processes that the material must pass. Material out of the warehouse is a product will be made. The products have been completed, are stored in the warehouse products. When the product is entered into the product warehouse, product data is also recorded by scanning the barcode contained on the label. By recording the condition of the product at each stage of production, we can know the availability of the product in a production unit in the form of a raw material, the product being processed and the finished product.

Experimental Investigation of Friction Stir Welded AA5052 using Square and Pentagonal Tool Pins

Aluminium alloy of AA5052 has wide acceptance in marine, aircraft, gas tankers, sheet metal work, fuel lines because of high strength to weight ratio. Unlike the fusion welding process, friction stir welding (FSW) is one of the solid state welding process where the coalescence between two metals is produced by generating frictional heat between non consumable tool and base material. Parameters in FSW like weld speed, rotational speed, tool pin profile and axial force play the major role in determining the strength of weld. In this experimental work, an effort has been made to perceive the effect of weld speed and pin profile on the weld nugget zone of AA5052. Two different tool pin profiles (square, pentagon) have been used to weld the joints at three different weld speeds (40 mm/min, 60 mm/min, 80 mm/min). Tensile properties, hardness and impact strength of welds have been evaluated. From this study, it is found that weld obtained by using pentagon pin at 60 mm/min weld speed produced the mechanically good weld compared to other welds.

Optimisation Of Process Parameters Of Electrical Discharge Machining Of Fabricated AA 6061/ 10% Al2 O3 Aluminium Based Metal Matrix Composite

As we know non conventional machining methods are used for machining very hard materials and for making difficult shapes.Electrical discharge machining (EDM) process is one of the most commonly used non conventional machining processes for machining hard, brittle materials like composites. It is commonly used in die making industries for developing complex profiles in dies related to sheet metal work, etc. It is commonly used for machining metal matrix composites which are very hard materials. Aluminium based metal matrix composites are widely used in aeronautical and defence parts because of their advanced properties like high strength to weight ratio, etc. At first the material was fabricated using stir casting set up which was the part of research work. The work piece material selected in this study was AA 6061/ 10%Al2O3 based metal matrix composite which was fabricated by stir casting process with the help of newly developed stir casting set up. After fabrication, the characterisation of samples was done using SEM and mechanical. The EDM process was selected for machining composite samples with input parameters like gap current (A), pulse on time (μs) and duty factor. In this machining process the output response was material removal rate. The optimisation of process parameters was done using Taguchi method with the help of ANOVA test and S/ N ratio. Analysis of variance was performed to find the significance of machining parameters in this experimental work.

Investigation of a partial, inductive short-time heat treatment of thin metal sheets integrated into the forming process

Flanging is a widespread method in the sheet metal working industry to connect same or different materials by forming. Especially the sealing technology makes high demands on the flanging process: a low sheet thickness of the inner eyelet is necessary for proper sealing. The outer edges of the neck rings are mostly manufactured by shear cutting. The quality of the cut surface and the level of the local strain hardening influence decisively the limit of the flanging process by possible cracking. This paper is focused on the dependencies of these factors regarding thin metal sheets of different materials with a thickness down to 100 μm. It could be shown that strain hardening has a stronger effect on the process limits compared to the notch effect of the sheet edges when using standard values for the clearance of the shear cutting tool. Furthermore, a process is investigated with a partial inductive short-time heat treatment of the most deformed edge area. Due to the low thickness of the material and low heat capacities related thereto, it is possible to integrate a recrystallization annealing as single step into the forming process. As a result, the strain hardening can be removed from the affected zone directly between two forming steps to increase the process limits.

Plural Governance, Product Innovation, and Process Improvement in Buyer-supplier Relationships

In this study, we examine the role of plural governance, namely the combination of transactional and relational governance mechanisms, in influencing product innovation performance of buyer-supplier relationships (BSRs). This study posits three core arguments. First, we content that, due to their separate governing attributes, transactional and relational governance mechanisms independently rather than interactively influence product innovation in BSRs. As such, their effects are additive rather than complementary. Second, we argue that transactional and relational governance mechanisms have complementary attributes in governing BSRs toward process improvement, which in turn enhances product innovation. Third, we also argue that the presence of coercive power threat undermines the effect of transactional-relational plural governance on process improvement in BSRs. Results from our survey of 348 suppliers in the sheet metal working industry are largely consistent with our core arguments.

Reduction of Burr Formation for Conventional Shear Cutting of Boron-alloyed Sheets through Focused Heat Treatment

Conventional shear cutting is the most commonly used manufacturing process in sheet metal working. Due to its good automation capacity it is high productive and therefore it has a significant economic importance. However, the occurence of burr is still a remaining issue of the conventional shear cutting process. The burr has to be removed as they pose a high risk for functional and ergonomic aspects. Deburring requires additional processing steps in the production line, which are expensive and time-consuming. In the case of automotive industry components, the removal costs make up 15 % to 20 % of production costs. When it comes to precision components, such as engine parts, the cost equals even up to 30 %. Thus, it is worthwhile to aim for the avoidance or at least the reduction of burr formation.In this work, different heat treatment methods were applied to 4 mm thick 22MnB5 sheets, in order to increase the strength of the material and thereby reduce burr formation. For this purpose, the heat treatment methods case hardening, flame hardening, and plasma nitriding were studied. After punching the hardened sheets, the characteristic cutting surfaces were determined by tactile measuring. The results of the different heat treatment methods were compared regarding the resulting burr and evaluated by means of Vickers hardness measurements and microstructural analysis.

Framework for The Development of a New Reconfigurable Guillotine Shear and Bending Press Machine

In today's manufacturing world, consumer satisfaction is difficult to achieve owing to the dynamic and continuous changes in their requirements and the rapid change in product designs. Research has been carried out on several innovations addressing this problem with various machine designs having been produced to deal effectively with the dynamic customer needs. Reconfigurable manufacturing systems (RMSs) and machines (RMTs), having superseded the dedicated manufacturing lines (DMLs) with dedicated machine tools (DMTs); and flexible manufacturing systems (FMSs) with their machines (FMTs), have led to a new era that takes the best aspects of both DMLs, FMSs and machines to conceive a new manufacturing system, RMS and RMTs that satisfy the dynamic nature of customer requirements. The aim of this paper is to present a structured framework that will optimise the development process of a new reconfigurable guillotine shear and bending press machine to be used in sheet metal work. The framework provides a guide for designers and manufactures of sheet metal machines in developing the new machine. To develop the framework, research used various tools such as reviewing existing literature on RMSs & RMTs, DMLs & DMTs, FMSs & FMTs and expected product change responsiveness. Research also explored literature on the development of machine modules for reconfigurable machines and reconfigurable technology systems. The framework seeks to provide a structured approach towards the machine development by highlighting important steps to be taken and various aspects to be considered. The results give a framework that will guide the development of a reconfigurable guillotine shear and bending press machine tool that can be configured and reconfigured to enable cutting and bending of varying sheet metal products by a single machine with dual functionality.

Preliminary Investigation of Micro-V-Bending

Bending in sheet metal forming is defined as uniformly straining process around a linear axis. A V-bending process is normally used in sheet metal working due to the tool and process simplicity. The main problem in bending process is a springback occurrence which causes an error in part dimension. In a micro level, the springback angle is difficult to be assessed because of the influence of size effects in all aspects of the system. The springback behavior has been investigated in many previous kinds of research. However, the springback correction is still needed to be studied extensively so that it can be implemented reliably in micro-bending. The purpose of this research is to investigate the influence of punch velocity and holding time to the springback angle. The process is performed to the 0.1 mm thickness of copper foil. The punch velocities are 0.1 mm/s, 1 mm/s, and 10 mm/s. While the variation of holding time, which is set during the bottoming stage, are 7 s, 9 s, and 11 s. The result shows that the punch velocity clearly influences the springback angle. In addition, the holding time during the bottoming stage is a potential factor in springback angle correction.

Preliminary study for online monitoring during the punching process

Monitoring of the punching operation plays an important role in enhancing product quality and tooling protection. In sheet metal working, most monitoring methods use tonnage/cutting force signal. In this study, the potential of vibration signal in the frequency range from 0 to 1000 Hz for punching monitoring is reported. The experiment is conducted by using a punch with a diameter of 0.8 mm and a speed of 50 rpm. The sheet material is SUS304 with a thickness of 0.5 mm. During the experiments, the signals, the tool conditions, and the burr formation are observed. The results show that there is a correlation between tool conditions with vibration signal. The influence of tool wear, an indication of punch breakage, and an incident of punch breakage are prominent. By the development of wear, the burr height increases and an increase in vibration amplitude is observed. When the burr height grows up to 3.5 times, certain vibrational peak amplitude increases around 15 times. This will be remarkable results for online monitoring because the off-line measurement of burr height can be substituted by vibration measurement. Based on these results, it can be concluded that the vibration signals at this frequency range have the potential for monitoring the tool condition and burr formation in the punching process.

A cross-sectional survey of hand arm vibration symptoms among angle grinder operators employed in sheet metal work in North India

A cross-sectional survey of hand arm vibration symptoms among angle grinder operators employed in sheet metal work in North India

A cross-sectional survey of hand arm vibration symptoms among angle grinder operators employed in sheet metal work in North India

This study investigates the prevalence of hand arm vibration symptoms and musculoskeletal disorders in the hand and arm of the angle grinder operators of sheet metal industries located in Chandigarh and nearby industrial areas in Northern India. Hand-transmitted vibration was measured in 42 sheet metal industries. A total of 83 workers, who were mainly employed for grinding job, were interviewed and vibration characteristics were measured using tri-axial accelerometer. Hand arm vibration symptoms, musculoskeletal complaints in hands and its correlation with tool weight were investigated. Results shown 84% daily vibration exposure measurements exceeded exposure action value (EAV) and 24% measurements exceeded exposure limit value (ELV). Hand arm vibration symptoms were finger numbness (40%), tingling (29%) and vibration white finger (VWF) (13%). Hand arm vibration symptoms in the workers were not significantly associated with tool weight. However, tool weight was significantly associated with musculoskeletal complaints in wrist, forearm and elbow of the workers. Preventive measures to reduce musculoskeletal complaints are proposed.

Noise Induced Hearing Impairment Amongst Industrial Hand Grinder Operators in Tractor Auxiliary Industry

Grinding operation is very important part of any automobile or sheet metal work industry. A study was conducted in tractor auxiliary industry to assess the noise level, in which the industrial hand grinder operator is working. Arphi 500 MKIII portable audiometer was used to measure noise induced hearing loss caused to operators because of excessive noise of hand grinder operation. Operators were audio metrically examined before and after a day's work to find temporary threshold shift. Their threshold of hearing was compared with that of normal person of that age group to find out permanent threshold shift. Noise level of grinding operation ranged from 100.91 to 113.31 dB(A). TTS of all the workers and also minor to major PTS at all audiometric frequencies were observed. A dip at 4 kHz was observed in all audiograms. All the audiograms were convex downward indicating more loss at higher frequencies. Posture of worker while working was an important aspect to explain the difference of TTS and PTS w.r.t. left and right ears. Some ways and means were suggested to protect workers from ill effects of noise and a few immediate possible suggestions were implemented. Results were encouraging and there was appreciable reduction in worker's noise exposure level (1.96–21%). Also, the general ambience of working environment improved tremendously with drastic cut in worker complaints.

Process Design for Hybrid Sheet Metal Components

The global trends towards improving fuel efficiency and reducing CO2 emissions are the key drivers for lightweight solutions. In sheet metal processing, this can be achieved by the use of materials with a supreme strength-to-weight and stiffness-to-weight ratio. Besides monolithic materials such as high-strength or light metals, in particular metal–plastic composite sheets are able to provide outstanding mechanical properties. Thus, the adaption of conventional, well-established forming methods for the processing of hybrid sheet metals is a current challenge for the sheet metal working industry. In this work, the planning phase for a conventional sheet metal forming process is studied aiming at the forming of metal–plastic composite sheets. The single process steps like material characterization, FE analysis, tool design and development of robust process parameters are studied in detail and adapted to the specific properties of metal–plastic composites. In material characterization, the model of the hybrid laminate needs to represent not only the mechanical properties of the individual combined materials, but also needs to reflect the behaviour of the interface zone between them. Based on experience, there is a strong dependency on temperature as well as strain rate. While monolithic materials show a moderate anisotropic behaviour, loads on laminates in different directions generate different strain states and completely different failure modes. During the FE analysis, thermo-mechanic and thermo-dynamic effects influence the temperature distribution within tool and work pieces and subsequently the forming behaviour. During try out and production phase, those additional influencing factors are limiting the process window even more and therefore need to be considered for the design of a robust forming process. A roadmap for sheet metal forming adjusted to metal–plastic composites is presented in this paper.

Sliding wear behavior of aluminum alloy coating prepared by two-wire electric arc spray process

Free standing aluminum alloy coating was successfully prepared by two-wire arc spray process which can in future replace sheet metal work in light industries. The wear behavior of the coating was determined using pin on disc machine under dry conditions at 20 ° C with three different pin materials, viz., brass, medium-carbon steel, and high-carbon steel. The wear rate was found to increase whereas the coefficient of friction of the coating was found to decrease with increased load and sliding conditions. The worn surfaces were examined with scanning electron microscopy (SEM), X-ray diffractometry (XRD), and energy-dispersive X-ray spectroscopy (EDS), and the microhardness to determine the wear mechanism of the coating.

Observed use of voluntary controls to reduce physical exposures among sheet metal workers of the mechanical trade

IntroductionLittle is known about the transfer into the workplace of interventions designed to reduce the physical demands of sheet metal workers. MethodsWe reviewed videos from a case series of 15 sheet metal worksite assessments performed in 2007–2009 to score postures and physical loads, and to observe the use of recommended interventions to reduce physical exposures in sheet metal activities made by a NIOSH stakeholder meeting in 2002. ResultsWorkers showed consistent use of material handling devices, but we observed few uses of recommended interventions to reduce exposures during overhead work. Workers spent large proportions of time in awkward shoulder elevation and low back rotation postures. ConclusionsIn addition to the development of new technologies and system designs, increased adoption of existing tools and practices could reduce time spent in awkward postures and other risks for musculoskeletal disorders in sheet metal work.