Pub Date : 2021-01-01DOI: 10.1051/MFREVIEW/2021012
F. M. Mwania, M. Maringa, J. G. van der Walt
Additive manufacturing (AM), is one of the key components of the 4th industrial revolution. Polymer laser sintering (PLS) is a subset of AM that is commonly used to process polymers, and which achieves good surface finish, good mechanical properties of finished products and for which there is no need for support structures. However, the requirements for polymeric powder for PLS are strident. Moreover, PLS subjects polymeric feed powders to high temperatures that lead to degradation of their thermal, rheological, and physical properties and is thus an impediment to their recyclability. Therefore, it is imperative to investigate the degree of polymer degradation or aging before re-using the material. This paper reviews the common techniques that are employed to characterize the suitability of polymeric powders for use and re-use in the PLS process. These include, but are not limited to, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), laser diffraction analysis, gas pycnometry, scanning electron microscopy (SEM), and melt flow index (MFI) testing.
{"title":"A review of the techniques used to characterize laser sintering of polymeric powders for use and re-use in additive manufacturing","authors":"F. M. Mwania, M. Maringa, J. G. van der Walt","doi":"10.1051/MFREVIEW/2021012","DOIUrl":"https://doi.org/10.1051/MFREVIEW/2021012","url":null,"abstract":"Additive manufacturing (AM), is one of the key components of the 4th industrial revolution. Polymer laser sintering (PLS) is a subset of AM that is commonly used to process polymers, and which achieves good surface finish, good mechanical properties of finished products and for which there is no need for support structures. However, the requirements for polymeric powder for PLS are strident. Moreover, PLS subjects polymeric feed powders to high temperatures that lead to degradation of their thermal, rheological, and physical properties and is thus an impediment to their recyclability. Therefore, it is imperative to investigate the degree of polymer degradation or aging before re-using the material. This paper reviews the common techniques that are employed to characterize the suitability of polymeric powders for use and re-use in the PLS process. These include, but are not limited to, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), laser diffraction analysis, gas pycnometry, scanning electron microscopy (SEM), and melt flow index (MFI) testing.","PeriodicalId":51873,"journal":{"name":"Manufacturing Review","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57964234","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-01DOI: 10.1051/MFREVIEW/2021002
A. Mocioiu, O. Mocioiu
The objective of our investigations consists in the thermal characterization of SiO2-PbO-Na2O vitreous materials in order to establish their properties for applications mainly as sealants. In order to evaluate the vitreous material − metal adherence, the thermal expansion coefficients (α) from experimental and theoretic data were determined. The differential thermal analysis of studied materials give the information about temperatures characteristic to glass transition, crystallization and melting. Dilatometer measurements were performed in air atmosphere in order to establish thermal coefficients of the materials. Softening and flowing characteristic of the vitreous materials were established by heating microscope measurements. The difference between thermal expansion coefficient (α) of the vitreous materials (10.2 × 10−6K−1 and 17.6 × 10−6K−1) and thermal expansion coefficient of the steel substrate OL 38 (10.8 × 10−6K−1) is under 37%. This value is fit for a good adherence between materials.
{"title":"Thermal behavior of lead silicate vitreous materials for sealants","authors":"A. Mocioiu, O. Mocioiu","doi":"10.1051/MFREVIEW/2021002","DOIUrl":"https://doi.org/10.1051/MFREVIEW/2021002","url":null,"abstract":"The objective of our investigations consists in the thermal characterization of SiO2-PbO-Na2O vitreous materials in order to establish their properties for applications mainly as sealants. In order to evaluate the vitreous material − metal adherence, the thermal expansion coefficients (α) from experimental and theoretic data were determined. The differential thermal analysis of studied materials give the information about temperatures characteristic to glass transition, crystallization and melting. Dilatometer measurements were performed in air atmosphere in order to establish thermal coefficients of the materials. Softening and flowing characteristic of the vitreous materials were established by heating microscope measurements. The difference between thermal expansion coefficient (α) of the vitreous materials (10.2 × 10−6K−1 and 17.6 × 10−6K−1) and thermal expansion coefficient of the steel substrate OL 38 (10.8 × 10−6K−1) is under 37%. This value is fit for a good adherence between materials.","PeriodicalId":51873,"journal":{"name":"Manufacturing Review","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57964466","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-01DOI: 10.1051/mfreview/2021028
D. Klenam, Gabriel Seun Ogunwande, T. Omotosho, Blessing Ozah, N. Maledi, S. I. Hango, A. Fabuyide, Lesego Mohlala, J. W. van der Merwe, M. Bodunrin
An overview of welding methods and process parameters and its effects on mechanical behaviour and structural integrity of magnesium and its alloys are discussed. These alloys are less dense and beneficial structural alloys for improved energy efficiency, eco-friendliness and driver of circular economic model for sustainable design and innovative ecosystem. While the application of Mg-alloys is projected to increase, understanding the mechanical behaviour and structural integrity of welded joints are critical. Thus, fusion and solid-state welding processes of these alloys are discussed with emphasis on mechanical characterization. Laser welding is the most effective fusion welding technique for most Mg alloys whereas, the predominant solid-state method is friction stir welding. The importance of process variables such as heat inputs, welding velocity (speed) and post weld treatments on the microstructural evolution, on mechanical and physical properties of the distinct zones of the weld joints are described. The weldment is the most susceptible to failure due to phase transformation, defects such as microporosity and relatively coarse grain sizes after solidification. The implication of the design of quality weld joints of Mg alloys are explored with areas for future research directions briefly discussed.
{"title":"Welding of magnesium and its alloys: an overview of methods and process parameters and their effects on mechanical behaviour and structural integrity of the welds","authors":"D. Klenam, Gabriel Seun Ogunwande, T. Omotosho, Blessing Ozah, N. Maledi, S. I. Hango, A. Fabuyide, Lesego Mohlala, J. W. van der Merwe, M. Bodunrin","doi":"10.1051/mfreview/2021028","DOIUrl":"https://doi.org/10.1051/mfreview/2021028","url":null,"abstract":"An overview of welding methods and process parameters and its effects on mechanical behaviour and structural integrity of magnesium and its alloys are discussed. These alloys are less dense and beneficial structural alloys for improved energy efficiency, eco-friendliness and driver of circular economic model for sustainable design and innovative ecosystem. While the application of Mg-alloys is projected to increase, understanding the mechanical behaviour and structural integrity of welded joints are critical. Thus, fusion and solid-state welding processes of these alloys are discussed with emphasis on mechanical characterization. Laser welding is the most effective fusion welding technique for most Mg alloys whereas, the predominant solid-state method is friction stir welding. The importance of process variables such as heat inputs, welding velocity (speed) and post weld treatments on the microstructural evolution, on mechanical and physical properties of the distinct zones of the weld joints are described. The weldment is the most susceptible to failure due to phase transformation, defects such as microporosity and relatively coarse grain sizes after solidification. The implication of the design of quality weld joints of Mg alloys are explored with areas for future research directions briefly discussed.","PeriodicalId":51873,"journal":{"name":"Manufacturing Review","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57964575","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-01DOI: 10.1051/mfreview/2021016
D. Markatos, C. Katsiropoulos, K. Tserpes, S. Pantelakis
In the present study, a holistic End-of-Life (EoL) Index is introduced to serve as a decision support tool for choosing the optimal recycling process among a number of alternative recycling techniques of CFRP waste. For the choice of the optimal recycling process, quality of the recycled fibers as well as cost and environmental impact of the recycling methods under consideration, are accounted for. Quality is interpreted as the reusability potential of the recycled fibers; that is quantified through the equivalent volume fraction of recycled fibers that balances the mechanical properties of a composite composed of a certain volume fraction of virgin fibers. The proposed Index is offering an estimated balanced score, quantifying a trade-off between the reusability potential of the recycled fibers as well as the cost and the environmental impact of the recycling methods considered.
{"title":"A holistic End-of-Life (EoL) Index for the quantitative impact assessment of CFRP waste recycling techniques","authors":"D. Markatos, C. Katsiropoulos, K. Tserpes, S. Pantelakis","doi":"10.1051/mfreview/2021016","DOIUrl":"https://doi.org/10.1051/mfreview/2021016","url":null,"abstract":"In the present study, a holistic End-of-Life (EoL) Index is introduced to serve as a decision support tool for choosing the optimal recycling process among a number of alternative recycling techniques of CFRP waste. For the choice of the optimal recycling process, quality of the recycled fibers as well as cost and environmental impact of the recycling methods under consideration, are accounted for. Quality is interpreted as the reusability potential of the recycled fibers; that is quantified through the equivalent volume fraction of recycled fibers that balances the mechanical properties of a composite composed of a certain volume fraction of virgin fibers. The proposed Index is offering an estimated balanced score, quantifying a trade-off between the reusability potential of the recycled fibers as well as the cost and the environmental impact of the recycling methods considered.","PeriodicalId":51873,"journal":{"name":"Manufacturing Review","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57964316","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-01DOI: 10.1051/mfreview/2021024
D. Duc Trung
This paper presents a multi-criteria decision making (MCDM) for a turning process. An experimental process was performed according to the sequence of a matrix using the Taguchi method with nine experiments. The parameters including workpiece speed, feed rate, depth of cut, and nose radius were selected as the input variables. At each experiment, three cutting force components that were measured in the three directions X, Y, and Z, were Fx, Fy, and Fz, respectively. The value of Material Removal Rate (MRR) was also calculated at each experiment. The main purpose of this study is determination of an experiment in total performed experiments simultaneously ensuring the minimum Fx, Fy, and Fz and the maximum MRR. The Entropy method was applied to determine the weights for parameters Fx, Fx, Fx, and MRR. Eight MCDM methods were applied for multi-criteria decision making, this has not been performed in any studies. The implementation steps of each method were also presented in this paper. Seven ones of these eight methods determined the best experiment in total nine performed experiments. A new multi-criteria decision-making method as well as orientation for the further works were also proposed in this study.
{"title":"A combination method for multi-criteria decision making problem in turning process","authors":"D. Duc Trung","doi":"10.1051/mfreview/2021024","DOIUrl":"https://doi.org/10.1051/mfreview/2021024","url":null,"abstract":"This paper presents a multi-criteria decision making (MCDM) for a turning process. An experimental process was performed according to the sequence of a matrix using the Taguchi method with nine experiments. The parameters including workpiece speed, feed rate, depth of cut, and nose radius were selected as the input variables. At each experiment, three cutting force components that were measured in the three directions X, Y, and Z, were Fx, Fy, and Fz, respectively. The value of Material Removal Rate (MRR) was also calculated at each experiment. The main purpose of this study is determination of an experiment in total performed experiments simultaneously ensuring the minimum Fx, Fy, and Fz and the maximum MRR. The Entropy method was applied to determine the weights for parameters Fx, Fx, Fx, and MRR. Eight MCDM methods were applied for multi-criteria decision making, this has not been performed in any studies. The implementation steps of each method were also presented in this paper. Seven ones of these eight methods determined the best experiment in total nine performed experiments. A new multi-criteria decision-making method as well as orientation for the further works were also proposed in this study.","PeriodicalId":51873,"journal":{"name":"Manufacturing Review","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57964493","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-01DOI: 10.1051/mfreview/2021025
J. Omotoyinbo, I. Oladele, J. M. Jabar, J. Borode, K. Alaneme, A. Akinwekomi, S. R. Oke, T. Omotosho, L. O. Saliu
This work investigates the influence of kaolin and dolomite on the properties of polyurethane foam. The selected fillers were pulverized and sieved to obtained < 90 μm that were used as reinforcements in the polyurethane matrix in a randomly dispersed mode. The matrix constituents were mixed in the same ratio while fillers were introduced via a one-shot system approach in predetermined proportions of 3–7 wt.%. The work was carried out to identify optimum fillers to be utilized in the production of polyurethane rigid foams given the effect of the fillers on the physical, mechanical, and chemical properties of the foam. FTIR, XRF, and SEM and mechanical property tests were carried out on the filled polyurethane foam. The presence of the fillers in the foam showed a rupture in the structure of the foams with the cells having similar arrangements. The addition of dolomite and Kaolin degrades the sulfonic acid groups and promoted the appearance of Si–O stretching vibration band. The density, hardness, flexural and compressive strengths of the polyurethane foam were enhanced with the the addition of dolomite and kaolin particles.
{"title":"Comparative investigation of the influence of kaolin and dolomite on the properties of polyurethane foam","authors":"J. Omotoyinbo, I. Oladele, J. M. Jabar, J. Borode, K. Alaneme, A. Akinwekomi, S. R. Oke, T. Omotosho, L. O. Saliu","doi":"10.1051/mfreview/2021025","DOIUrl":"https://doi.org/10.1051/mfreview/2021025","url":null,"abstract":"This work investigates the influence of kaolin and dolomite on the properties of polyurethane foam. The selected fillers were pulverized and sieved to obtained < 90 μm that were used as reinforcements in the polyurethane matrix in a randomly dispersed mode. The matrix constituents were mixed in the same ratio while fillers were introduced via a one-shot system approach in predetermined proportions of 3–7 wt.%. The work was carried out to identify optimum fillers to be utilized in the production of polyurethane rigid foams given the effect of the fillers on the physical, mechanical, and chemical properties of the foam. FTIR, XRF, and SEM and mechanical property tests were carried out on the filled polyurethane foam. The presence of the fillers in the foam showed a rupture in the structure of the foams with the cells having similar arrangements. The addition of dolomite and Kaolin degrades the sulfonic acid groups and promoted the appearance of Si–O stretching vibration band. The density, hardness, flexural and compressive strengths of the polyurethane foam were enhanced with the the addition of dolomite and kaolin particles.","PeriodicalId":51873,"journal":{"name":"Manufacturing Review","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57964506","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-01DOI: 10.1051/MFREVIEW/2021004
S. Babalola, K. Alaneme, S. R. Oke, L. Chown, N. Maledi, M. Bodunrin
The response of two different types of aluminium matrix composites (AMCs) reinforced with silicon carbide ceramic particulates or nickel metallic particulates to hot compression testing parameters was evaluated. The composites were produced via two-step stir-casting technique. Axisymmetric compression testing was performed on the samples at different deformation temperatures of 220 and 370 °Ϲ, 0.5 and 5 s−1 strain rates and total strains of 0.6 and 1.2. The initial and post-deformed microstructures were studied using optical and scanning electron microscopy. The results show that flow stress was significantly influenced by imposed deformation parameters and the type of reinforcements used in the AMCs. Nickel particulate reinforced aluminium matrix composite (AMC) showed superior resistance to deformation in comparison with silicon carbide reinforced AMC under the different testing conditions. In both AMCs, work hardening, dynamic recovery and dynamic recrystallisation influenced their response to imposed parameters. The signature of dynamic recrystallisation was very apparent in aluminium matrix composite reinforced with nickel particulates.
{"title":"Hot compression behaviour and microstructural evolution in aluminium based composites: an assessment of the role of reinforcements and deformation parameters","authors":"S. Babalola, K. Alaneme, S. R. Oke, L. Chown, N. Maledi, M. Bodunrin","doi":"10.1051/MFREVIEW/2021004","DOIUrl":"https://doi.org/10.1051/MFREVIEW/2021004","url":null,"abstract":"The response of two different types of aluminium matrix composites (AMCs) reinforced with silicon carbide ceramic particulates or nickel metallic particulates to hot compression testing parameters was evaluated. The composites were produced via two-step stir-casting technique. Axisymmetric compression testing was performed on the samples at different deformation temperatures of 220 and 370 °Ϲ, 0.5 and 5 s−1 strain rates and total strains of 0.6 and 1.2. The initial and post-deformed microstructures were studied using optical and scanning electron microscopy. The results show that flow stress was significantly influenced by imposed deformation parameters and the type of reinforcements used in the AMCs. Nickel particulate reinforced aluminium matrix composite (AMC) showed superior resistance to deformation in comparison with silicon carbide reinforced AMC under the different testing conditions. In both AMCs, work hardening, dynamic recovery and dynamic recrystallisation influenced their response to imposed parameters. The signature of dynamic recrystallisation was very apparent in aluminium matrix composite reinforced with nickel particulates.","PeriodicalId":51873,"journal":{"name":"Manufacturing Review","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57964535","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-12-01DOI: 10.1051/mfreview/2019027
R. Carbas, Miguel P. Palmares, L. D. da Silva
The use of composite materials in industry is growing due to various technological advances in composite materials accompanied by improvements in the structural adhesives used to bond them. Fibre metal laminates (FML's) are hybrid composite structures based on thin sheets of metal alloys and plies of fibre-reinforced polymeric materials. The fibre/metal composite technology combines the advantages of metallic materials and fibre-reinforced matrix systems. The aim of the present study is to use a concept similar to that used in FML to increase the peel strength of composite materials and increase the joint strength of hybrid laminates aluminium carbon-fibre adhesive joints. Carbon fibre-reinforced plastic (CFRP) composites were modified by including one or several aluminium sheets during the laminate manufacture to enhance the composite through the thickness properties. The objective was to identify the joint configuration that gives the best joint strength improvement in relation to the CFRP only reference joint. An adhesive developed for the aeronautical industry was used to manufacture single lap joints for tensile testing. Experimental and numerical studies were undertaken on modified CFRP joints to investigate the joint strength of different lay-up solutions to prevent delamination of adherends.
{"title":"Experimental and FE study of hybrid laminates aluminium carbon-fibre joints with different lay-up configurations","authors":"R. Carbas, Miguel P. Palmares, L. D. da Silva","doi":"10.1051/mfreview/2019027","DOIUrl":"https://doi.org/10.1051/mfreview/2019027","url":null,"abstract":"The use of composite materials in industry is growing due to various technological advances in composite materials accompanied by improvements in the structural adhesives used to bond them. Fibre metal laminates (FML's) are hybrid composite structures based on thin sheets of metal alloys and plies of fibre-reinforced polymeric materials. The fibre/metal composite technology combines the advantages of metallic materials and fibre-reinforced matrix systems. The aim of the present study is to use a concept similar to that used in FML to increase the peel strength of composite materials and increase the joint strength of hybrid laminates aluminium carbon-fibre adhesive joints. Carbon fibre-reinforced plastic (CFRP) composites were modified by including one or several aluminium sheets during the laminate manufacture to enhance the composite through the thickness properties. The objective was to identify the joint configuration that gives the best joint strength improvement in relation to the CFRP only reference joint. An adhesive developed for the aeronautical industry was used to manufacture single lap joints for tensile testing. Experimental and numerical studies were undertaken on modified CFRP joints to investigate the joint strength of different lay-up solutions to prevent delamination of adherends.","PeriodicalId":51873,"journal":{"name":"Manufacturing Review","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1051/mfreview/2019027","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44292622","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-12-01DOI: 10.1051/mfreview/2019029
S. Brechelt, P. Neef, H. Wiche, V. Wesling
Due to the increased demands for reducing CO2 emissions, improving fuel efficiency of modern vehicles has been continuously monitored. The body of a typical compact car design has a weight share of approx. 40%. In addition to increasing torsional stiffness and crash safety of the body, the aim is also to reduce the overall weight at the same time. In order to achieve these individual requirements, the use of three-sheet steel stack-ups with adhesive applications for car body construction is one of the current strategies used in automobile manufacturing. Adhesive applications lead to a change in process behavior of resistance spot welding. The effective weldability lobe is reduced and an adjusted preheat current is necessary to reconstitute the weldability of a component. Depending on squeeze time and electrode force the adhesive will be displaced. For an asymmetric sheet stack-up, the electrical resistance for every faying surface is highly differentiated. During welding, a specific characteristic of the electrical resistance is created for each individual material combination. These characteristics can be analyzed by using an online measurement device. In this manuscript, different sheet stack-ups are examined with regard to their weldability lobes and their process behavior. The individual three-sheet steel stack-ups used are made of low carbon steel (DX51), HSLA-steel (HX340) and UHS-steel (22MnB5). The corresponding characteristics of electrical resistance will be recorded by using an online measurement device. In addition, the process of adhesive displacement during the squeeze time and the initial welding current are discussed on the basis of the electrical energy generated in the component to be welded. The obtained results contribute to a direct verification of the welding process and an automatic detection of possible imperfect welds.
{"title":"Spot weld bonding − process behavior of three-sheet steel stack‑ups and analysis strategies with online measuring methods","authors":"S. Brechelt, P. Neef, H. Wiche, V. Wesling","doi":"10.1051/mfreview/2019029","DOIUrl":"https://doi.org/10.1051/mfreview/2019029","url":null,"abstract":"Due to the increased demands for reducing CO2 emissions, improving fuel efficiency of modern vehicles has been continuously monitored. The body of a typical compact car design has a weight share of approx. 40%. In addition to increasing torsional stiffness and crash safety of the body, the aim is also to reduce the overall weight at the same time. In order to achieve these individual requirements, the use of three-sheet steel stack-ups with adhesive applications for car body construction is one of the current strategies used in automobile manufacturing. Adhesive applications lead to a change in process behavior of resistance spot welding. The effective weldability lobe is reduced and an adjusted preheat current is necessary to reconstitute the weldability of a component. Depending on squeeze time and electrode force the adhesive will be displaced. For an asymmetric sheet stack-up, the electrical resistance for every faying surface is highly differentiated. During welding, a specific characteristic of the electrical resistance is created for each individual material combination. These characteristics can be analyzed by using an online measurement device. In this manuscript, different sheet stack-ups are examined with regard to their weldability lobes and their process behavior. The individual three-sheet steel stack-ups used are made of low carbon steel (DX51), HSLA-steel (HX340) and UHS-steel (22MnB5). The corresponding characteristics of electrical resistance will be recorded by using an online measurement device. In addition, the process of adhesive displacement during the squeeze time and the initial welding current are discussed on the basis of the electrical energy generated in the component to be welded. The obtained results contribute to a direct verification of the welding process and an automatic detection of possible imperfect welds.","PeriodicalId":51873,"journal":{"name":"Manufacturing Review","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1051/mfreview/2019029","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42941789","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-09-01DOI: 10.1051/mfreview/2020031
A. Sobetkii, Laurentiu Mosinoiu, A. Paraschiv, Mircea Corban, R. Piticescu, G. Matache
The possibility of depositing multi layers made of metals/alloys and high temperature ceramics by electron beam physical evaporation process under high vacuum (EB-PVD) on the surface of a parallelepiped sample made by selective laser melting (SLM) from a Ni base refractory super alloy was experimentally tested. The SEM-EDAX micro structural analysis revealed the morphology and thickness of the coatings consisting of a NiCrAlY base alloy as bonding layer and three successive YSZ, LZO and GZO ceramic layers on the Ni-based super alloy substrate obtained by additive manufacturing. The adhesion of the layer deposited was evaluated by the scratch test method. The analysis highlighted the importance of pre-preparing the surface of the additive manufactured substrates, in order to control the adhesion and uniformity of the deposited layers.
{"title":"Microstructural aspects of the protective ceramic coatings applied on the surfaces of refractory alloys produced by additive manufacturing","authors":"A. Sobetkii, Laurentiu Mosinoiu, A. Paraschiv, Mircea Corban, R. Piticescu, G. Matache","doi":"10.1051/mfreview/2020031","DOIUrl":"https://doi.org/10.1051/mfreview/2020031","url":null,"abstract":"The possibility of depositing multi layers made of metals/alloys and high temperature ceramics by electron beam physical evaporation process under high vacuum (EB-PVD) on the surface of a parallelepiped sample made by selective laser melting (SLM) from a Ni base refractory super alloy was experimentally tested. The SEM-EDAX micro structural analysis revealed the morphology and thickness of the coatings consisting of a NiCrAlY base alloy as bonding layer and three successive YSZ, LZO and GZO ceramic layers on the Ni-based super alloy substrate obtained by additive manufacturing. The adhesion of the layer deposited was evaluated by the scratch test method. The analysis highlighted the importance of pre-preparing the surface of the additive manufactured substrates, in order to control the adhesion and uniformity of the deposited layers.","PeriodicalId":51873,"journal":{"name":"Manufacturing Review","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1051/mfreview/2020031","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46846896","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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