Pub Date : 2023-04-20DOI: 10.1080/00325899.2023.2202950
L. Emanuelli, Giacomo Segata, M. Perina, Martin Regolini, Valentina Nicchiotti, A. Molinari
ABSTRACT The microstructure and mechanical properties of 17-4 stainless steel produced by Binder Jetting (BJT) and heat treated according to the standard conditions for the 17-4 PH steel (H900 and H1100) were investigated. The sintered relative density is 97.8% with a slightly anisotropic shrinkage. Tensile strength and elongation are above the minimum required for the wrought steel and comparable to those of the same material manufactured by Metal Injection Molding. They are also better than those reported in the literature for the 17-4 PH stainless steel manufactured by BJT. Tensile elongation at fracture is anisotropic, highlighting a significant dependence of the non-uniform plastic deformation on the direction.
{"title":"Study of microstructure and mechanical properties of 17-4 PH stainless steel produced via Binder Jetting","authors":"L. Emanuelli, Giacomo Segata, M. Perina, Martin Regolini, Valentina Nicchiotti, A. Molinari","doi":"10.1080/00325899.2023.2202950","DOIUrl":"https://doi.org/10.1080/00325899.2023.2202950","url":null,"abstract":"ABSTRACT The microstructure and mechanical properties of 17-4 stainless steel produced by Binder Jetting (BJT) and heat treated according to the standard conditions for the 17-4 PH steel (H900 and H1100) were investigated. The sintered relative density is 97.8% with a slightly anisotropic shrinkage. Tensile strength and elongation are above the minimum required for the wrought steel and comparable to those of the same material manufactured by Metal Injection Molding. They are also better than those reported in the literature for the 17-4 PH stainless steel manufactured by BJT. Tensile elongation at fracture is anisotropic, highlighting a significant dependence of the non-uniform plastic deformation on the direction.","PeriodicalId":20392,"journal":{"name":"Powder Metallurgy","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2023-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41706863","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-04-19DOI: 10.1080/00325899.2023.2201487
R. de Oro Calderon, C. Gierl-Mayer, H. Danninger
ABSTRACT In the upcoming years, a reduction in the use of critical elements, such as Ni and Cu, with unstable prices and high demand from the electromobility sector will become increasingly important for the PM-industry. Cr-alloyed sintered steels offer attractive properties at a moderate cost, but so far mostly Cr-prealloyed grades have been used. This work analyses the microstructural homogenisation process when Cr is introduced as admixed elemental powder. It is shown how – due to its high carbon affinity – Cr particles act as ‘internal carbon-getters’. There is an intermediate ‘heterogenization’ of the microstructure, i.e. the iron matrix is decarburised due to the formation of (Cr, Fe)-carbides. Final homogenisation depends on the formation of a transient liquid phase through the eutectic reaction between carbides and the iron matrix. Thus, the microstructure is not only sensitive to aspects such as sintering temperature or Cr-particle size but also to the heating rate and small variations in nominal carbon.
{"title":"Microstructural evolution during sintering of Fe-Cr-C steels prepared from admixed elemental powders","authors":"R. de Oro Calderon, C. Gierl-Mayer, H. Danninger","doi":"10.1080/00325899.2023.2201487","DOIUrl":"https://doi.org/10.1080/00325899.2023.2201487","url":null,"abstract":"ABSTRACT In the upcoming years, a reduction in the use of critical elements, such as Ni and Cu, with unstable prices and high demand from the electromobility sector will become increasingly important for the PM-industry. Cr-alloyed sintered steels offer attractive properties at a moderate cost, but so far mostly Cr-prealloyed grades have been used. This work analyses the microstructural homogenisation process when Cr is introduced as admixed elemental powder. It is shown how – due to its high carbon affinity – Cr particles act as ‘internal carbon-getters’. There is an intermediate ‘heterogenization’ of the microstructure, i.e. the iron matrix is decarburised due to the formation of (Cr, Fe)-carbides. Final homogenisation depends on the formation of a transient liquid phase through the eutectic reaction between carbides and the iron matrix. Thus, the microstructure is not only sensitive to aspects such as sintering temperature or Cr-particle size but also to the heating rate and small variations in nominal carbon.","PeriodicalId":20392,"journal":{"name":"Powder Metallurgy","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2023-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47238466","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-04-12DOI: 10.1080/00325899.2023.2198796
Gilmar Nogueira, T. Gervais, V. Peres, Estelle Marc, C. L. Martin
ABSTRACT A Discrete Element Method (DEM) model is used to simulate the compaction and sintering of ceramic oxides. The process kinematics is decomposed into loading, unloading and ejection of the pellet. Interactions between the particles are considered elastoplastic by implementing a model able to tackle large densities. A simplified approach is used in the sintering stage, which focuses on the final part geometry rather than kinetics. The results are in good agreement with experimental data and FEM simulations from the literature regarding density gradient, elastic spring-back and final geometry. The simulations show that the friction coefficient between the agglomerates and the die is the primary factor for the density gradient in the pellet. This density gradient induces non-homogeneous sintering, which results in a final geometry with a diabolo effect. It is the first time that DEM reproduces this effect with the advantage of considering explicitly the particulate nature of the powder. GRAPHICAL ABSTRACT
{"title":"Using discrete simulations of compaction and sintering to predict final part geometry","authors":"Gilmar Nogueira, T. Gervais, V. Peres, Estelle Marc, C. L. Martin","doi":"10.1080/00325899.2023.2198796","DOIUrl":"https://doi.org/10.1080/00325899.2023.2198796","url":null,"abstract":"ABSTRACT\u0000 A Discrete Element Method (DEM) model is used to simulate the compaction and sintering of ceramic oxides. The process kinematics is decomposed into loading, unloading and ejection of the pellet. Interactions between the particles are considered elastoplastic by implementing a model able to tackle large densities. A simplified approach is used in the sintering stage, which focuses on the final part geometry rather than kinetics. The results are in good agreement with experimental data and FEM simulations from the literature regarding density gradient, elastic spring-back and final geometry. The simulations show that the friction coefficient between the agglomerates and the die is the primary factor for the density gradient in the pellet. This density gradient induces non-homogeneous sintering, which results in a final geometry with a diabolo effect. It is the first time that DEM reproduces this effect with the advantage of considering explicitly the particulate nature of the powder. GRAPHICAL ABSTRACT","PeriodicalId":20392,"journal":{"name":"Powder Metallurgy","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2023-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44522493","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-03-29DOI: 10.1080/00325899.2023.2194478
K. Lim, M. Hayat, Kumarmani Jena, Wen Zhang, Lu Li, Pengtao Cao
ABSTRACT Owing to the different characteristics of each of the multiple polymers, obtaining a homogenous metal injection moulding (MIM) feedstock blend is challenging. Therefore, studying interactions between the polymeric components is vital for achieving suitable MIM feedstocks. We report on the effects of different compatibilisers – EGMA and E40 – on the interactions in polyoxymethylene (POM) and polypropylene (PP) blends. We measured contact angles and performed Fourier transform infrared spectroscopy and atomic force microscopy analyses to identify the suitable compatibiliser that yields a feedstock with excellent properties. It was found that the binder system based on EGMA-3 demonstrates the lowest contact angle and best miscibility for the POM/PP blends compared to E40. This enhanced interaction lies in the chemistry of EGMA, having an active site that reduces the interfacial tension between the components of the POM/PP blend. Subsequently, this creates a positive interaction between the polymers and metal powders, ensuring good adhesion within the feedstock.
{"title":"Interactions of polymeric components in a POM-based binder system for titanium metal injection moulding feedstocks","authors":"K. Lim, M. Hayat, Kumarmani Jena, Wen Zhang, Lu Li, Pengtao Cao","doi":"10.1080/00325899.2023.2194478","DOIUrl":"https://doi.org/10.1080/00325899.2023.2194478","url":null,"abstract":"ABSTRACT\u0000 Owing to the different characteristics of each of the multiple polymers, obtaining a homogenous metal injection moulding (MIM) feedstock blend is challenging. Therefore, studying interactions between the polymeric components is vital for achieving suitable MIM feedstocks. We report on the effects of different compatibilisers – EGMA and E40 – on the interactions in polyoxymethylene (POM) and polypropylene (PP) blends. We measured contact angles and performed Fourier transform infrared spectroscopy and atomic force microscopy analyses to identify the suitable compatibiliser that yields a feedstock with excellent properties. It was found that the binder system based on EGMA-3 demonstrates the lowest contact angle and best miscibility for the POM/PP blends compared to E40. This enhanced interaction lies in the chemistry of EGMA, having an active site that reduces the interfacial tension between the components of the POM/PP blend. Subsequently, this creates a positive interaction between the polymers and metal powders, ensuring good adhesion within the feedstock.","PeriodicalId":20392,"journal":{"name":"Powder Metallurgy","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2023-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43586212","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-03-27DOI: 10.1080/00325899.2023.2190477
Swathi K. Manchili, B. Malladi, M. Vattur Sundaram, E. Hryha, L. Nyborg
ABSTRACT High sintered density is desired for heavy-duty applications and there are different ways through which the sintered density can be improved. In the current study, nanopowder is blended to the conventionally used micrometre-sized water-atomised steel powder to evaluate its impact on sintering. Both the powder variants, without and with nanopowder, were subjected to thermogravimetry analysis, and uniaxially compacted to the same green density of 7.15 g/cc or 90% relative density and sintered at 1250°C in pure hydrogen. A comparative analysis was performed with respect to the microstructural evolution between the micro and micro/nano bimodal powder compacts. JMatPro and electron backscattered diffraction was used to understand the microstructural evolution. An attempt was made to understand the improved linear shrinkage in the micro/nano bimodal powder compact using a combination of microstructure analysis and chemical analysis.
{"title":"Influence of iron nanopowder addition on the densification of chromium-prealloyed water-atomised powder metallurgy steel admixed with nickel","authors":"Swathi K. Manchili, B. Malladi, M. Vattur Sundaram, E. Hryha, L. Nyborg","doi":"10.1080/00325899.2023.2190477","DOIUrl":"https://doi.org/10.1080/00325899.2023.2190477","url":null,"abstract":"ABSTRACT High sintered density is desired for heavy-duty applications and there are different ways through which the sintered density can be improved. In the current study, nanopowder is blended to the conventionally used micrometre-sized water-atomised steel powder to evaluate its impact on sintering. Both the powder variants, without and with nanopowder, were subjected to thermogravimetry analysis, and uniaxially compacted to the same green density of 7.15 g/cc or 90% relative density and sintered at 1250°C in pure hydrogen. A comparative analysis was performed with respect to the microstructural evolution between the micro and micro/nano bimodal powder compacts. JMatPro and electron backscattered diffraction was used to understand the microstructural evolution. An attempt was made to understand the improved linear shrinkage in the micro/nano bimodal powder compact using a combination of microstructure analysis and chemical analysis.","PeriodicalId":20392,"journal":{"name":"Powder Metallurgy","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2023-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41546986","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-03-27DOI: 10.1080/00325899.2023.2192036
C. Pauzon, Ahmad Raza, Imran Hanif, S. Dubiez-Le Goff, J. Moverare, E. Hryha
ABSTRACT High layer thicknesses for laser powder bed fusion are promising for productivity increase. However, these are associated with increased process instability, spatter generation and powder degradation, crucial for alloys sensitive to oxygen. The effect of increasing layer thickness from 30 to 60 µm is studied focusing on Ti-6Al-4V spatter formation during LPBF and its characterisation, with scanning and transmission electron microscopy, combustion analysis and X-ray photoelectron spectroscopy. Results indicate that spatters are covered with a uniform Ti-Al-based oxide layer and Al-rich oxide particulates, the thickness of which is about twice that present on virgin powder. The oxygen content was about 60% higher in spatters compared to the virgin powder. The study highlights that increasing the layer thickness to 60 µm permits to reduce the total generation of spatters by ∼40%, while maintaining similar spatter characteristics and static tensile properties. Hence, this allows to increase build rate without compromising process robustness. Highlights Increased layer thickness from 30 to 60 µm resulted in ∼40% lower amount of spatter generated per build Increased layer thickness from 30 to 60 µm resulted in ∼17% higher amount of generated spatter per scanned layer Increase in bulk oxygen content by >60% was registered for spatter compared to the virgin powder in both cases The oxide layer is about twice thicker on the spatter particles compared to virgin powder
{"title":"Effect of layer thickness on spatter properties during laser powder bed fusion of Ti–6Al–4V","authors":"C. Pauzon, Ahmad Raza, Imran Hanif, S. Dubiez-Le Goff, J. Moverare, E. Hryha","doi":"10.1080/00325899.2023.2192036","DOIUrl":"https://doi.org/10.1080/00325899.2023.2192036","url":null,"abstract":"ABSTRACT High layer thicknesses for laser powder bed fusion are promising for productivity increase. However, these are associated with increased process instability, spatter generation and powder degradation, crucial for alloys sensitive to oxygen. The effect of increasing layer thickness from 30 to 60 µm is studied focusing on Ti-6Al-4V spatter formation during LPBF and its characterisation, with scanning and transmission electron microscopy, combustion analysis and X-ray photoelectron spectroscopy. Results indicate that spatters are covered with a uniform Ti-Al-based oxide layer and Al-rich oxide particulates, the thickness of which is about twice that present on virgin powder. The oxygen content was about 60% higher in spatters compared to the virgin powder. The study highlights that increasing the layer thickness to 60 µm permits to reduce the total generation of spatters by ∼40%, while maintaining similar spatter characteristics and static tensile properties. Hence, this allows to increase build rate without compromising process robustness. Highlights Increased layer thickness from 30 to 60 µm resulted in ∼40% lower amount of spatter generated per build Increased layer thickness from 30 to 60 µm resulted in ∼17% higher amount of generated spatter per scanned layer Increase in bulk oxygen content by >60% was registered for spatter compared to the virgin powder in both cases The oxide layer is about twice thicker on the spatter particles compared to virgin powder","PeriodicalId":20392,"journal":{"name":"Powder Metallurgy","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2023-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43408478","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-03-20DOI: 10.1080/00325899.2023.2191236
Denis Mutel, Simon Gélinas, C. Blais
ABSTRACT Metal powders developed for additive manufacturing processes need to achieve specific flow characteristics to be considered suitable. However, for the relationship between powder flow and the morphological characteristics of individual particles can be difficult to establish. In this context, artificial intelligence appears to be the perfect tool to clarify the imprecision surrounding this type of interaction. The work summarised in this manuscript first uses a neural network architecture (Mask R-CNN) allowing the segmentation of individual water-atomised tool steel particles in micrographs acquired in scanning electron microscopy. The micrographs of individual particles or their shape descriptors are then processed using and comparing two different strategies, namely linear regression or unsupervised machine learning (ML), to corelate the information collected on individual particles with the rheological properties of powder specimens. The approach developed aims to acquire new knowledge regarding specific particle characteristics that are required to optimise powder flowability for laser powder-bed fusion.
{"title":"Rheological characterisation of water atomised tool steel powders developed for laser powder bed fusion by supervised and unsupervised machine learning","authors":"Denis Mutel, Simon Gélinas, C. Blais","doi":"10.1080/00325899.2023.2191236","DOIUrl":"https://doi.org/10.1080/00325899.2023.2191236","url":null,"abstract":"ABSTRACT Metal powders developed for additive manufacturing processes need to achieve specific flow characteristics to be considered suitable. However, for the relationship between powder flow and the morphological characteristics of individual particles can be difficult to establish. In this context, artificial intelligence appears to be the perfect tool to clarify the imprecision surrounding this type of interaction. The work summarised in this manuscript first uses a neural network architecture (Mask R-CNN) allowing the segmentation of individual water-atomised tool steel particles in micrographs acquired in scanning electron microscopy. The micrographs of individual particles or their shape descriptors are then processed using and comparing two different strategies, namely linear regression or unsupervised machine learning (ML), to corelate the information collected on individual particles with the rheological properties of powder specimens. The approach developed aims to acquire new knowledge regarding specific particle characteristics that are required to optimise powder flowability for laser powder-bed fusion.","PeriodicalId":20392,"journal":{"name":"Powder Metallurgy","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2023-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42531797","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-03-16DOI: 10.1080/00325899.2023.2179207
E. Soares Barreto, J. Wegner, M. Frey, S. Kleszczynski, R. Busch, V. Uhlenwinkel, L. Mädler, N. Ellendt
ABSTRACT Laser powder bed fusion of metals (PBF-LB/M) is advantageous for manufacturing bulk metallic glasses with size and geometrical freedom. However, the oxygen uptake along the production chain can negatively impact the generation of high-quality, amorphous parts. In this context, Cu–Ti-based alloys were gas-atomised and additively manufactured using commercial- (CP) and high-purity (HP) feedstocks. The oxygen absorption in each processing step was tracked and related to the amorphous phase formation and glass-forming ability (GFA) of alloys. Results show an increasing oxygen absorption, considerably influenced by the starting feedstock, especially for CP. In HP material, the most contribution is inherent from the powder oxygen content. Results reveal the lack of influence of the oxygen content in the GFA. TEM analysis of commercial powder and PBF-LB/M sample show uniform and featureless micrographs, displaying the absence of oxygen-induced nucleation. The present contribution enhances the qualification and economic processability of amorphous metals by PBF-LB/M.
{"title":"Influence of oxygen in the production chain of Cu–Ti-based metallic glasses via laser powder bed fusion","authors":"E. Soares Barreto, J. Wegner, M. Frey, S. Kleszczynski, R. Busch, V. Uhlenwinkel, L. Mädler, N. Ellendt","doi":"10.1080/00325899.2023.2179207","DOIUrl":"https://doi.org/10.1080/00325899.2023.2179207","url":null,"abstract":"ABSTRACT Laser powder bed fusion of metals (PBF-LB/M) is advantageous for manufacturing bulk metallic glasses with size and geometrical freedom. However, the oxygen uptake along the production chain can negatively impact the generation of high-quality, amorphous parts. In this context, Cu–Ti-based alloys were gas-atomised and additively manufactured using commercial- (CP) and high-purity (HP) feedstocks. The oxygen absorption in each processing step was tracked and related to the amorphous phase formation and glass-forming ability (GFA) of alloys. Results show an increasing oxygen absorption, considerably influenced by the starting feedstock, especially for CP. In HP material, the most contribution is inherent from the powder oxygen content. Results reveal the lack of influence of the oxygen content in the GFA. TEM analysis of commercial powder and PBF-LB/M sample show uniform and featureless micrographs, displaying the absence of oxygen-induced nucleation. The present contribution enhances the qualification and economic processability of amorphous metals by PBF-LB/M.","PeriodicalId":20392,"journal":{"name":"Powder Metallurgy","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2023-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42410795","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-03-16DOI: 10.1080/00325899.2023.2189083
Junfeng Wang, Min Xia, Jialun Wu, C. Ge
ABSTRACT The clogging problem of close-coupled nozzles in the vacuum induction melting gas atomisation (VIGA) process is studied by numerical simulation and industrial experiments. To understand the factors affecting lick back on the nozzle, volume of fluid (VOF) multiphase flow model simulation was adopted to visualise the motion of alloy melt around the outer wall of the delivery tube in the primary atomisation process. When the melt orifice diameter is 4 mm and the atomisation pressure is close to 3.5 MPa, the atomisation process is continuous, the powder particle size is fine, and the atomiser can be reused. When the orifice diameter is 5 mm, and the atomisation pressure is greater than 2.5 MPa, the risk of nozzle clogging is avoided, the powder size is relatively coarse. In the case of using the same atomiser structure, this study explains the mechanism of lick-back and the resulting nozzle damage in VIGA units.
{"title":"Nozzle clogging in vacuum induction melting gas atomisation: influence of gas pressure and melt orifice diameter coupling","authors":"Junfeng Wang, Min Xia, Jialun Wu, C. Ge","doi":"10.1080/00325899.2023.2189083","DOIUrl":"https://doi.org/10.1080/00325899.2023.2189083","url":null,"abstract":"ABSTRACT The clogging problem of close-coupled nozzles in the vacuum induction melting gas atomisation (VIGA) process is studied by numerical simulation and industrial experiments. To understand the factors affecting lick back on the nozzle, volume of fluid (VOF) multiphase flow model simulation was adopted to visualise the motion of alloy melt around the outer wall of the delivery tube in the primary atomisation process. When the melt orifice diameter is 4 mm and the atomisation pressure is close to 3.5 MPa, the atomisation process is continuous, the powder particle size is fine, and the atomiser can be reused. When the orifice diameter is 5 mm, and the atomisation pressure is greater than 2.5 MPa, the risk of nozzle clogging is avoided, the powder size is relatively coarse. In the case of using the same atomiser structure, this study explains the mechanism of lick-back and the resulting nozzle damage in VIGA units.","PeriodicalId":20392,"journal":{"name":"Powder Metallurgy","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2023-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46879571","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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