H. Liao, Y. Zong, Kejiang Li, Zhisheng Bi, Chun-he Jiang, Jianliang Zhang, S. Ren
Precisely predicting the hopper discharge rate and trajectory is of great significance for industrial processing of granular materials. This study uses the DEM (Discrete Element Method)-based open-source software LIGGGHTS to analyze the flow behavior of spherical particles in six cone-shaped hoppers with different outlet shapes (circle, triangle, square, rectangle, pentagon and hexagon) with the various opening area. It was found that the particle flow velocity and mass flow rates are mainly determined by the outlet areas, while the outlet shape have an obvious influence on the particle trajectory which determines the stagnation area in the hopper. The results of the present study can provide meaningful guidance for the optimization of industrial hopper structure design and control.
{"title":"Effect of outlet characteristics and particle properties on the flow characteristics inside conical hoppers","authors":"H. Liao, Y. Zong, Kejiang Li, Zhisheng Bi, Chun-he Jiang, Jianliang Zhang, S. Ren","doi":"10.1051/metal/2022080","DOIUrl":"https://doi.org/10.1051/metal/2022080","url":null,"abstract":"Precisely predicting the hopper discharge rate and trajectory is of great significance for industrial processing of granular materials. This study uses the DEM (Discrete Element Method)-based open-source software LIGGGHTS to analyze the flow behavior of spherical particles in six cone-shaped hoppers with different outlet shapes (circle, triangle, square, rectangle, pentagon and hexagon) with the various opening area. It was found that the particle flow velocity and mass flow rates are mainly determined by the outlet areas, while the outlet shape have an obvious influence on the particle trajectory which determines the stagnation area in the hopper. The results of the present study can provide meaningful guidance for the optimization of industrial hopper structure design and control.","PeriodicalId":370509,"journal":{"name":"Metallurgical Research & Technology","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133909644","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}
T. Umadevi, Komala Sivanna Sridhara, M. Raju, P. Karthik, R. Sah, Maribasappanavar Basavaraja, Sanghamesh Desai
Iron ore pellet fines generation at direct reduced iron (DRI) plant is ranging from 10 to 12% during handling of the pellets from pellet plant to DRI plant. The generation of fines during handling depends on the quality of the produced pellets, mainly due to the abrasion index (AI) of the pellet. To reduce the generation of pellet fines, detailed laboratory studies have been carried out by coating the hematite iron ore pellet surface with magnetite fines generated from reduction roasting plant, and mixed magnetite fines with limestone fines. The coated green pellets were fired in a rising hearth furnace. The magnetite fines were varied from 0 to 2.5% as coating agent, and limestone fines was varied from 0 to 0.6% as coating agent mixed with magnetite fines. At optimum 1.5% magnetite fines as coating agent achieved better pellet properties and reduced the fines generation from 6.8 to 3.2% due to formation of secondary hematite phases at the pellet shell. With mixed 0.2% limestone and 1.5% magnetite fines reduced pellet fines generation from 6.8 to 4.2%. Reduction in fines generation with mixed fines was due to formation of secondary hematite and Ca-ferrite at the pellet surface. Secondary hematite and Ca ferrite phases having higher micro-hardness compared to other phases of iron ore pellet. The sequence of micro-hardness of the pellet phases is secondary hematite > Ca-ferrite > primary hematite > magnetite. The secondary hematite and Ca-ferrite formed at the pellet surface due to coating of magnetite as well as magnetite with limestone fines improved the overall pellet quality and reduced the generation of fines at DRI plant. Coating of magnetite fines alone showed better pellet properties with lesser fines generation compared to coating of mixed limestone and magnetite fines.
{"title":"Development of process for reduction in fines generation at direct reduced iron plant by coating of magnetite iron ore fines on hematite iron ore pellets","authors":"T. Umadevi, Komala Sivanna Sridhara, M. Raju, P. Karthik, R. Sah, Maribasappanavar Basavaraja, Sanghamesh Desai","doi":"10.1051/metal/2022088","DOIUrl":"https://doi.org/10.1051/metal/2022088","url":null,"abstract":"Iron ore pellet fines generation at direct reduced iron (DRI) plant is ranging from 10 to 12% during handling of the pellets from pellet plant to DRI plant. The generation of fines during handling depends on the quality of the produced pellets, mainly due to the abrasion index (AI) of the pellet. To reduce the generation of pellet fines, detailed laboratory studies have been carried out by coating the hematite iron ore pellet surface with magnetite fines generated from reduction roasting plant, and mixed magnetite fines with limestone fines. The coated green pellets were fired in a rising hearth furnace. The magnetite fines were varied from 0 to 2.5% as coating agent, and limestone fines was varied from 0 to 0.6% as coating agent mixed with magnetite fines. At optimum 1.5% magnetite fines as coating agent achieved better pellet properties and reduced the fines generation from 6.8 to 3.2% due to formation of secondary hematite phases at the pellet shell. With mixed 0.2% limestone and 1.5% magnetite fines reduced pellet fines generation from 6.8 to 4.2%. Reduction in fines generation with mixed fines was due to formation of secondary hematite and Ca-ferrite at the pellet surface. Secondary hematite and Ca ferrite phases having higher micro-hardness compared to other phases of iron ore pellet. The sequence of micro-hardness of the pellet phases is secondary hematite > Ca-ferrite > primary hematite > magnetite. The secondary hematite and Ca-ferrite formed at the pellet surface due to coating of magnetite as well as magnetite with limestone fines improved the overall pellet quality and reduced the generation of fines at DRI plant. Coating of magnetite fines alone showed better pellet properties with lesser fines generation compared to coating of mixed limestone and magnetite fines.","PeriodicalId":370509,"journal":{"name":"Metallurgical Research & Technology","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116744432","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}
Kai Wang, Yongjun Shi, Xiaoyu Zhou, C. Zhai, Yankuo Guo, Jianfeng Jiang
A new method of ultrasonic vibration combined with induction cladding was used to prepare nickel-based alloy coating on 45 steel to improve the properties of NiCrBSi coating by induction cladding. The temperature field distribution was simulated and analyzed by finite element method, and the optimum process parameters were determined. The transmission mechanism of ultrasonic wave in traditional non-contact ultrasonic vibration composite cladding was revealed. The effects of non-contact and contact ultrasonic vibration on the grain size, element distribution, porosity, and microhardness of the coating were studied. The cross-section of the coating was analyzed by using a scanning electron microscope, energy dispersive spectrometer, and microhardness tester. The results show that the properties of the coating prepared by non-contact ultrasonic vibration combined with induction cladding were not improved because most of the ultrasonic energy was emitted. In contact ultrasonic vibration combined induction cladding, dendrite structure was destroyed, and the coating grains were refined under the action of ultrasonic vibration. The porosity also decreased evidently under the action of ultrasonic cavitation effect. The microhardness of the coating top area been significantly improved in the microhardness test.
{"title":"Microstructure and properties of NiCrBSi coating formed by ultrasonic vibration combined with induction cladding","authors":"Kai Wang, Yongjun Shi, Xiaoyu Zhou, C. Zhai, Yankuo Guo, Jianfeng Jiang","doi":"10.1051/metal/2022017","DOIUrl":"https://doi.org/10.1051/metal/2022017","url":null,"abstract":"A new method of ultrasonic vibration combined with induction cladding was used to prepare nickel-based alloy coating on 45 steel to improve the properties of NiCrBSi coating by induction cladding. The temperature field distribution was simulated and analyzed by finite element method, and the optimum process parameters were determined. The transmission mechanism of ultrasonic wave in traditional non-contact ultrasonic vibration composite cladding was revealed. The effects of non-contact and contact ultrasonic vibration on the grain size, element distribution, porosity, and microhardness of the coating were studied. The cross-section of the coating was analyzed by using a scanning electron microscope, energy dispersive spectrometer, and microhardness tester. The results show that the properties of the coating prepared by non-contact ultrasonic vibration combined with induction cladding were not improved because most of the ultrasonic energy was emitted. In contact ultrasonic vibration combined induction cladding, dendrite structure was destroyed, and the coating grains were refined under the action of ultrasonic vibration. The porosity also decreased evidently under the action of ultrasonic cavitation effect. The microhardness of the coating top area been significantly improved in the microhardness test.","PeriodicalId":370509,"journal":{"name":"Metallurgical Research & Technology","volume":"205 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115034467","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}
The silicon content of the hot metal is not only an important indicator of the quality of the hot metal and blast furnace (BF) operation but also reflects the level of energy utilization and the thermal state within a BF. It is important to develop an accurate prediction model for hot metal silicon content. In present study, two models for predicting hot metal silicon content are developed based on two ensemble learning methods, random forest regression (RFR) and extreme gradient boosting (XGBoost). First, Box plot was used to visualize the collected data and determine extreme outliers in the raw data. Extreme outliers are replaced with null value, and all null value are filled by linear interpolation. Secondly, feature selection is performed using recursive feature elimination. Cross-validation is performed to optimize machine learning hyperparameters and having a robust accuracy measure. Based on this, two hot metal silicon content prediction models are developed. Finally, the prediction results of the two models are compared and evaluated. The results show that both ensemble learning models show good prediction performance in predicting hot metal silicon content, but the prediction performance of the RFR model is better than that of the XGBoost model and reaching 98.77%.
{"title":"Predictive modeling of the hot metal silicon content in blast furnace based on ensemble method","authors":"Dewen Jiang, Xinfu Zhou, Zhenyang Wang, Kejiang Li, Jianliang Zhang","doi":"10.1051/metal/2022074","DOIUrl":"https://doi.org/10.1051/metal/2022074","url":null,"abstract":"The silicon content of the hot metal is not only an important indicator of the quality of the hot metal and blast furnace (BF) operation but also reflects the level of energy utilization and the thermal state within a BF. It is important to develop an accurate prediction model for hot metal silicon content. In present study, two models for predicting hot metal silicon content are developed based on two ensemble learning methods, random forest regression (RFR) and extreme gradient boosting (XGBoost). First, Box plot was used to visualize the collected data and determine extreme outliers in the raw data. Extreme outliers are replaced with null value, and all null value are filled by linear interpolation. Secondly, feature selection is performed using recursive feature elimination. Cross-validation is performed to optimize machine learning hyperparameters and having a robust accuracy measure. Based on this, two hot metal silicon content prediction models are developed. Finally, the prediction results of the two models are compared and evaluated. The results show that both ensemble learning models show good prediction performance in predicting hot metal silicon content, but the prediction performance of the RFR model is better than that of the XGBoost model and reaching 98.77%.","PeriodicalId":370509,"journal":{"name":"Metallurgical Research & Technology","volume":"147 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116613982","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}
Brass alloys that meet ASTM C36000 standard were prepared from scrap copper alloys in this study. The mechanical properties of these brass alloy products were measured, and the results showed that yield strength, elongation, tensile strength, and hardness were respectively 164 N/mm2, 37.7%, 383 N/mm2, and 87.7 HV. The flow of elements in the brass alloy production process was also investigated using thermodynamic calculations and microstructural observations. It was discovered that elements such as Al, Mg, Pb, and Cd were easily oxidized as slag; Cd was easily volatilized at high temperatures, and impurities such as Fe, S, and P were precipitated as ZnS and Fe3P inclusions.
{"title":"Comprehensive utilization of valuable elements in brass alloy rods production through recovery of copper scraps","authors":"Yitong Xie, Lixia Shi, Ya-qiong Li, Zhixiang Fu, Lifeng Zhang","doi":"10.1051/metal/2022106","DOIUrl":"https://doi.org/10.1051/metal/2022106","url":null,"abstract":"Brass alloys that meet ASTM C36000 standard were prepared from scrap copper alloys in this study. The mechanical properties of these brass alloy products were measured, and the results showed that yield strength, elongation, tensile strength, and hardness were respectively 164 N/mm2, 37.7%, 383 N/mm2, and 87.7 HV. The flow of elements in the brass alloy production process was also investigated using thermodynamic calculations and microstructural observations. It was discovered that elements such as Al, Mg, Pb, and Cd were easily oxidized as slag; Cd was easily volatilized at high temperatures, and impurities such as Fe, S, and P were precipitated as ZnS and Fe3P inclusions.","PeriodicalId":370509,"journal":{"name":"Metallurgical Research & Technology","volume":"57 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124085320","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}
The supersonic jet characteristics of the oxygen lance nozzle play an important role in converter melting. In this study, the jet characteristics of swirl-type oxygen lance were investigated by numerical simulation. The velocity field, jet coalescence behavior and jet impact cavity area of swirl-type oxygen lance with different inclination and swirl angles were analyzed. The results demonstrate that compared with the traditional oxygen lance, the swirl angle accelerates the attenuation of the jet. However, the tangential velocity of jet is conducive to the rapid melting of the slag in the steelmaking process. With the increase of swirl angle and inclination angle, the velocity of jet decreases, the temperature of jet increases and the independence between jets is improved. With the increase of the swirl angle, the tangential velocity of the swirl-type oxygen lance increases, but the possibility of slag adhering to the nozzle surface increases. The effective impact area varies non-monotonically with the swirl angle. The optimum inclination and swirl angle of the swirl-type oxygen lance for a 260 t converter are 15° and 10° respectively. When the oxygen flow rate increases, the decay of jet velocity decreases and the effective impact area increases.
{"title":"Effect of multi-angle parameter on fluid flow characteristics of swirl-type oxygen lance","authors":"Xi Wang, Peng Han, Kun Liu","doi":"10.1051/metal/2022029","DOIUrl":"https://doi.org/10.1051/metal/2022029","url":null,"abstract":"The supersonic jet characteristics of the oxygen lance nozzle play an important role in converter melting. In this study, the jet characteristics of swirl-type oxygen lance were investigated by numerical simulation. The velocity field, jet coalescence behavior and jet impact cavity area of swirl-type oxygen lance with different inclination and swirl angles were analyzed. The results demonstrate that compared with the traditional oxygen lance, the swirl angle accelerates the attenuation of the jet. However, the tangential velocity of jet is conducive to the rapid melting of the slag in the steelmaking process. With the increase of swirl angle and inclination angle, the velocity of jet decreases, the temperature of jet increases and the independence between jets is improved. With the increase of the swirl angle, the tangential velocity of the swirl-type oxygen lance increases, but the possibility of slag adhering to the nozzle surface increases. The effective impact area varies non-monotonically with the swirl angle. The optimum inclination and swirl angle of the swirl-type oxygen lance for a 260 t converter are 15° and 10° respectively. When the oxygen flow rate increases, the decay of jet velocity decreases and the effective impact area increases.","PeriodicalId":370509,"journal":{"name":"Metallurgical Research & Technology","volume":"159 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124453510","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}
Enhancing corrosion resistance in stainless-ssteel alloys is a paramount objective in the petroleum industry. This study investigated the effects of the previous cold working and welding processes on the mechanical properties and corrosion rates of 204 Cu stainless steel in different aggressive environments (crude oil, freshwater, and seawater). The experimental sets were supported by microstructure analysis. The mean weight loss method was employed to determine the corrosion rates, which were optimized using the Taguchi method. The ferrite and austenite phase bands, as well as the deformed portions of austenite, are pushed to flatten out during cold working, which increases the material’s hardness. Cold-worked steels were welded, creating an annealed area around the HAZ in addition to the usual weld zones, which demonstrated partial microstructure recovery and hardness reduction. HAZ showed signs of iron overload and chromium nitride precipitation. Cold-worked specimens only showed reduced corrosion resistance to 30% of the initial rate and reduced thickness. Moreover, the Taguchi optimization technique indicated that the corrosion environment has the most effect on the corrosion rate compared to the cold work ratio for welded and non-welded stainless-steel specimens.
{"title":"Optimize the corrosion behavior of AISI 204Cu stainless steel in different environments under previous cold working and welding","authors":"H. Lieth, M. Jabbar, R. Jassim, R. Al-Sabur","doi":"10.1051/metal/2023058","DOIUrl":"https://doi.org/10.1051/metal/2023058","url":null,"abstract":"Enhancing corrosion resistance in stainless-ssteel alloys is a paramount objective in the petroleum industry. This study investigated the effects of the previous cold working and welding processes on the mechanical properties and corrosion rates of 204 Cu stainless steel in different aggressive environments (crude oil, freshwater, and seawater). The experimental sets were supported by microstructure analysis. The mean weight loss method was employed to determine the corrosion rates, which were optimized using the Taguchi method. The ferrite and austenite phase bands, as well as the deformed portions of austenite, are pushed to flatten out during cold working, which increases the material’s hardness. Cold-worked steels were welded, creating an annealed area around the HAZ in addition to the usual weld zones, which demonstrated partial microstructure recovery and hardness reduction. HAZ showed signs of iron overload and chromium nitride precipitation. Cold-worked specimens only showed reduced corrosion resistance to 30% of the initial rate and reduced thickness. Moreover, the Taguchi optimization technique indicated that the corrosion environment has the most effect on the corrosion rate compared to the cold work ratio for welded and non-welded stainless-steel specimens.","PeriodicalId":370509,"journal":{"name":"Metallurgical Research & Technology","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128910825","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}
A. Moradi, A. Heidari, K. Amini, F. Aghadavoudi, R. Abedinzadeh
Shot peening is a method that increases the surface compressive residual stress, controls the growth of surface micro-cracks, and improves surface properties such as increasing hardness of surface and wear resistance by fabricating a compact layer of nanostructure on the surface. In this study, the effect of shot peening process on compressive residual stress, microstructure, hardness of surface, wear, and surface roughness of Ti-6Al-4V alloy was investigated. Accordingly, specimens of Ti-6Al-4V alloy were shot peened with steel pellets with a diameter of 0.4 mm. Steel pellets were impinged on the surface of Ti-6Al-4V alloy with the nozzles air pressure of 1bar and the impinging angle of 90°. Then the samples were subjected to shot peening for 20, 40, and 60 min. Subsequently, the grain size, micro-strain and compressive residual stress of the surface were investigated by using X-ray diffraction (XRD) analysis. Also, microstructures formed on the surface were investigated with Scanning electron microscopy (SEM). In addition, mechanical properties of the surfaces were investigated by performing hardness and wear tests. The results showed that the grains were refined from the size of 150 nm in the raw specimen to 29.2, 28.5 and 28.3 nm over the shot peening times of 20, 40, and 60 min. Also, the shot peening operation led to the increase of 55%, 57%, and 63% hardness of surface, the increase of 32%, 37%, and 43% of surface wear resistance, and the increasing of surface roughness in comparison with raw specimen over the shot peening times of 20, 40, and 60 min. The reasons for improving the surface layer properties of titanium alloy include refining and nano-crystallization of the grains and creation of nanostructure on surface layer. On the other hand, as a compact layer of nanostructure is formed on the surface via shot peening, the amount of residual stress on the surface increased from 938 MPa during 20 min to 1232 MPa during 60 min of shot peening operation. Also, based on the surface wear investigation of titanium alloy the wear mechanisms included abrasive, adhesive, and tribo-chemical which decreased by increasing the hardness of surface in the shot peening process.
{"title":"The effect of shot peening time on mechanical properties and residual stress in Ti-6Al-4V alloy","authors":"A. Moradi, A. Heidari, K. Amini, F. Aghadavoudi, R. Abedinzadeh","doi":"10.1051/metal/2022036","DOIUrl":"https://doi.org/10.1051/metal/2022036","url":null,"abstract":"Shot peening is a method that increases the surface compressive residual stress, controls the growth of surface micro-cracks, and improves surface properties such as increasing hardness of surface and wear resistance by fabricating a compact layer of nanostructure on the surface. In this study, the effect of shot peening process on compressive residual stress, microstructure, hardness of surface, wear, and surface roughness of Ti-6Al-4V alloy was investigated. Accordingly, specimens of Ti-6Al-4V alloy were shot peened with steel pellets with a diameter of 0.4 mm. Steel pellets were impinged on the surface of Ti-6Al-4V alloy with the nozzles air pressure of 1bar and the impinging angle of 90°. Then the samples were subjected to shot peening for 20, 40, and 60 min. Subsequently, the grain size, micro-strain and compressive residual stress of the surface were investigated by using X-ray diffraction (XRD) analysis. Also, microstructures formed on the surface were investigated with Scanning electron microscopy (SEM). In addition, mechanical properties of the surfaces were investigated by performing hardness and wear tests. The results showed that the grains were refined from the size of 150 nm in the raw specimen to 29.2, 28.5 and 28.3 nm over the shot peening times of 20, 40, and 60 min. Also, the shot peening operation led to the increase of 55%, 57%, and 63% hardness of surface, the increase of 32%, 37%, and 43% of surface wear resistance, and the increasing of surface roughness in comparison with raw specimen over the shot peening times of 20, 40, and 60 min. The reasons for improving the surface layer properties of titanium alloy include refining and nano-crystallization of the grains and creation of nanostructure on surface layer. On the other hand, as a compact layer of nanostructure is formed on the surface via shot peening, the amount of residual stress on the surface increased from 938 MPa during 20 min to 1232 MPa during 60 min of shot peening operation. Also, based on the surface wear investigation of titanium alloy the wear mechanisms included abrasive, adhesive, and tribo-chemical which decreased by increasing the hardness of surface in the shot peening process.","PeriodicalId":370509,"journal":{"name":"Metallurgical Research & Technology","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129832740","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}
Muhammad Fawad, M. Sadiq, A. Nawaz, M. Arif, S. Bibi, Bilal Islam, S. Ahmad, S. Noor, Iftikhar Hussain
Sn-Ag3.0-Cu0.5 samples were initially prepared by melt mixing in induction furnace which were also re-melted and re-solidified. Afterwards, four Sn-Ag3.0-Cu0.5 specimens were additionally heat treated at 40, 60, 80 and 100 °C respectively for limited time span of 6 h. The Sn-Ag3.0-Cu0.5 specimens revealed 1.03, 1.10, 1.15 and 1.13 times improvement in hardness values relative to untreated or reference specimen. Similarly, ultimate tensile strength exhibited 1.08, 1.18, 1.25 and 1.21 correspondingly when compared with reference specimen. X-ray diffraction pattern further justified Sn-Ag3.0-Cu0.5 alloy and negated appearance of any new phase after heat treatment. Average crystallite sizes were also reduced to 1.06, 1.10, 1.42 and 1.09 folds after heat treatment at 40, 60, 80 and 100 °C for 6 h. Similarly, both phases (β-Sn and intermetallic compounds) also evidenced decrement in their crystallite sizes in comparison to reference specimen. Moreover, resistivity also depicted increase of 1.13, 1.24, 1.32 and 1.25 times accordingly. Hence, our results show that the SAC-305 samples treated at 80 °C for 6 h may prove effective in countering electromigration problems by minimizing tensile strain gradients as well as current densities. Hence the SAC-305 specimen treated at 80 °C for 6 h may be recommended as potential candidate in solder applications.
{"title":"Effects of heat treatment on mechanical, electrical properties and curtailment of electromigration in Sn-Ag3.0-Cu0.5 soldering based alloys","authors":"Muhammad Fawad, M. Sadiq, A. Nawaz, M. Arif, S. Bibi, Bilal Islam, S. Ahmad, S. Noor, Iftikhar Hussain","doi":"10.1051/metal/2022084","DOIUrl":"https://doi.org/10.1051/metal/2022084","url":null,"abstract":"Sn-Ag3.0-Cu0.5 samples were initially prepared by melt mixing in induction furnace which were also re-melted and re-solidified. Afterwards, four Sn-Ag3.0-Cu0.5 specimens were additionally heat treated at 40, 60, 80 and 100 °C respectively for limited time span of 6 h. The Sn-Ag3.0-Cu0.5 specimens revealed 1.03, 1.10, 1.15 and 1.13 times improvement in hardness values relative to untreated or reference specimen. Similarly, ultimate tensile strength exhibited 1.08, 1.18, 1.25 and 1.21 correspondingly when compared with reference specimen. X-ray diffraction pattern further justified Sn-Ag3.0-Cu0.5 alloy and negated appearance of any new phase after heat treatment. Average crystallite sizes were also reduced to 1.06, 1.10, 1.42 and 1.09 folds after heat treatment at 40, 60, 80 and 100 °C for 6 h. Similarly, both phases (β-Sn and intermetallic compounds) also evidenced decrement in their crystallite sizes in comparison to reference specimen. Moreover, resistivity also depicted increase of 1.13, 1.24, 1.32 and 1.25 times accordingly. Hence, our results show that the SAC-305 samples treated at 80 °C for 6 h may prove effective in countering electromigration problems by minimizing tensile strain gradients as well as current densities. Hence the SAC-305 specimen treated at 80 °C for 6 h may be recommended as potential candidate in solder applications.","PeriodicalId":370509,"journal":{"name":"Metallurgical Research & Technology","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130711965","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}
The utilization of low-grade laterite ores has become necessary due to the intensive mining of high-grade nickel sulphide ores for a long time. In this study, metallic reduction roasting followed by magnetic separation to produce ferronickel alloy and abandon gangue minerals provides an effectively treatment for laterite ores. The experimental results indicate that ferronickel alloy containing more than 7.5% Ni with its recovery of 95% and more than 70% Fe with its recovery of 90% was produced successfully from the low-grade laterite ore. In the metallic reduction roasting process, the thermodynamic analysis displayed that the higher temperature promotes the conversion percentage of the oxidic nickel and iron to metallic nickel and iron. The ferronickel particle morphology with a liquid-solid growth and aggregation mechanism in the reduced laterite ore were investigated by SEM/EDS. XRD analysis revealed that the nickel laterite ore was transformed from hortonolite (MgOx · FeO2-x · SiO2) to forsterite (MgOx · CaOy · SiO2) during the metallic reduction process.
{"title":"Phase transformation in the metallic reduction process of low-grade laterite nickel ores for ferronickel alloy production","authors":"Tang Biao, L. Bing, Y. Hui","doi":"10.1051/metal/2023023","DOIUrl":"https://doi.org/10.1051/metal/2023023","url":null,"abstract":"The utilization of low-grade laterite ores has become necessary due to the intensive mining of high-grade nickel sulphide ores for a long time. In this study, metallic reduction roasting followed by magnetic separation to produce ferronickel alloy and abandon gangue minerals provides an effectively treatment for laterite ores. The experimental results indicate that ferronickel alloy containing more than 7.5% Ni with its recovery of 95% and more than 70% Fe with its recovery of 90% was produced successfully from the low-grade laterite ore. In the metallic reduction roasting process, the thermodynamic analysis displayed that the higher temperature promotes the conversion percentage of the oxidic nickel and iron to metallic nickel and iron. The ferronickel particle morphology with a liquid-solid growth and aggregation mechanism in the reduced laterite ore were investigated by SEM/EDS. XRD analysis revealed that the nickel laterite ore was transformed from hortonolite (MgOx · FeO2-x · SiO2) to forsterite (MgOx · CaOy · SiO2) during the metallic reduction process.","PeriodicalId":370509,"journal":{"name":"Metallurgical Research & Technology","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129539023","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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