Pub Date : 2025-03-18DOI: 10.1016/j.powtec.2025.120944
Nastaran Khazali, Thomas Russell, Pavel Bedrikovetsky
This study evaluates the effectiveness of n-particle filtration models in approximating the behaviour of heterogeneous colloidal suspension flows in porous media. Using a numerical investigation, the study examines binary (n = 2) and ternary (n = 3) particle models to approximate breakthrough curves and retention profiles of systems with varying filtration coefficient distributions. The results show that binary and ternary models can effectively replicate the behaviour of systems with lower heterogeneity, where the ratio of maximum to minimum filtration coefficients remains moderate. However, as heterogeneity increases (higher coefficients of variation), the accuracy of lower-particle models decreases, and more particles are required to maintain model fidelity. The study highlights practical guidelines for model selection, recommending binary models for moderate heterogeneity and ternary models for high heterogeneity. It cautions against oversimplifying highly heterogeneous systems with low-particle models and provides a framework for iterative model refinement based on experimental data. This work offers a robust approach for modelling particle transport and retention in porous media, with applications in aquifer recharge, oil recovery, and environmental engineering.
{"title":"Approximating heterogeneous colloidal transport by n-population filtration models","authors":"Nastaran Khazali, Thomas Russell, Pavel Bedrikovetsky","doi":"10.1016/j.powtec.2025.120944","DOIUrl":"10.1016/j.powtec.2025.120944","url":null,"abstract":"<div><div>This study evaluates the effectiveness of n-particle filtration models in approximating the behaviour of heterogeneous colloidal suspension flows in porous media. Using a numerical investigation, the study examines binary (<em>n</em> = 2) and ternary (<em>n</em> = 3) particle models to approximate breakthrough curves and retention profiles of systems with varying filtration coefficient distributions. The results show that binary and ternary models can effectively replicate the behaviour of systems with lower heterogeneity, where the ratio of maximum to minimum filtration coefficients remains moderate. However, as heterogeneity increases (higher coefficients of variation), the accuracy of lower-particle models decreases, and more particles are required to maintain model fidelity. The study highlights practical guidelines for model selection, recommending binary models for moderate heterogeneity and ternary models for high heterogeneity. It cautions against oversimplifying highly heterogeneous systems with low-particle models and provides a framework for iterative model refinement based on experimental data. This work offers a robust approach for modelling particle transport and retention in porous media, with applications in aquifer recharge, oil recovery, and environmental engineering.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"458 ","pages":"Article 120944"},"PeriodicalIF":4.5,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143725913","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-17DOI: 10.1016/j.powtec.2025.120940
Hongfa Sun , Siliang Zhou , Jibo Long , Li Zeng
The process of loading and unloading bulk materials is common in industrial production. This process has become a major source of dust fugitive in industrial plants. In order to understand its dust production mechanism, this paper establishes a physical model of particles flow impacting on the material heap. The CFD-DEM coupling method is validated using experimental data. The effects of heap angle, particle velocity, and hopper outlet diameter on the characteristics of entrained airflow and particle motion are analyzed. The index of ‘entrained flux’ is proposed to assess the influence range of entrained air at the material heap tail. The results indicate that the entrained air velocity exhibits a Gaussian distribution along the normal direction of the material heap surface, with significant fluctuations at the upper part of the material heap and the formation of vortex motion at the material heap tail. The magnitude of the entrained flux is primarily influenced by the location of the vortex, which gradually moves away from the material heap as particle velocity and hopper outlet diameter increase. Conversely, as the heap angle increases, the vortex movement tends to approach the material heap. An objective weighting method is used to analyze the influence weights of the entrained flux, revealing that particle velocity has the highest weight of 39 %, while the hopper outlet diameter has the lowest weight of 26 %.
{"title":"CFD-DEM coupled study on the characteristics of entrained air and particles dispersion during the particles flow impacting on a heap surface process","authors":"Hongfa Sun , Siliang Zhou , Jibo Long , Li Zeng","doi":"10.1016/j.powtec.2025.120940","DOIUrl":"10.1016/j.powtec.2025.120940","url":null,"abstract":"<div><div>The process of loading and unloading bulk materials is common in industrial production. This process has become a major source of dust fugitive in industrial plants. In order to understand its dust production mechanism, this paper establishes a physical model of particles flow impacting on the material heap. The CFD-DEM coupling method is validated using experimental data. The effects of heap angle, particle velocity, and hopper outlet diameter on the characteristics of entrained airflow and particle motion are analyzed. The index of ‘entrained flux’ is proposed to assess the influence range of entrained air at the material heap tail. The results indicate that the entrained air velocity exhibits a Gaussian distribution along the normal direction of the material heap surface, with significant fluctuations at the upper part of the material heap and the formation of vortex motion at the material heap tail. The magnitude of the entrained flux is primarily influenced by the location of the vortex, which gradually moves away from the material heap as particle velocity and hopper outlet diameter increase. Conversely, as the heap angle increases, the vortex movement tends to approach the material heap. An objective weighting method is used to analyze the influence weights of the entrained flux, revealing that particle velocity has the highest weight of 39 %, while the hopper outlet diameter has the lowest weight of 26 %.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"457 ","pages":"Article 120940"},"PeriodicalIF":4.5,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143686958","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-17DOI: 10.1016/j.powtec.2025.120912
Jianxin Hu , Jingjing Xu , Jiafeng Xie , Dingyi Pan
Cohesive forces lead to widespread particle flocculation, significantly altering the settling dynamics of particle clouds. The microscopic dynamics of cloud settling require further investigation, especially considering inter-particle cohesion and poly-dispersity caused by particle density variations in practical engineering applications. Motivated by this, we employ an Eulerian–Lagrangian computational fluid dynamics-discrete element method (CFD–DEM) coupling model to investigate the settling behavior of bi-disperse cohesive particle clouds in a stationary flow field. The results indicate that, for non-cohesive clouds, the large inertia of heavy particles prevents them from following the vortex back into the cloud, resulting in the upward segregation and leakage of heavy particles. The introduction of cohesion reduces the vertical particle segregation at low density ratios and intensifies segregation at high density ratios. This behavior is associated with floc formation and vortex structures. These segregation characteristics provide valuable insights into the directional recovery of heavy metal particles from wastewater. Furthermore, involving cohesion promotes the horizontal dispersion of particles by influencing the vortex structure. It contributes to a better understanding of particle dispersion in aquatic environments and providing guidance for the use of flocculants in engineering applications.
{"title":"Numerical investigation on settling process of bi-disperse cohesive particle clouds","authors":"Jianxin Hu , Jingjing Xu , Jiafeng Xie , Dingyi Pan","doi":"10.1016/j.powtec.2025.120912","DOIUrl":"10.1016/j.powtec.2025.120912","url":null,"abstract":"<div><div>Cohesive forces lead to widespread particle flocculation, significantly altering the settling dynamics of particle clouds. The microscopic dynamics of cloud settling require further investigation, especially considering inter-particle cohesion and poly-dispersity caused by particle density variations in practical engineering applications. Motivated by this, we employ an Eulerian–Lagrangian computational fluid dynamics-discrete element method (CFD–DEM) coupling model to investigate the settling behavior of bi-disperse cohesive particle clouds in a stationary flow field. The results indicate that, for non-cohesive clouds, the large inertia of heavy particles prevents them from following the vortex back into the cloud, resulting in the upward segregation and leakage of heavy particles. The introduction of cohesion reduces the vertical particle segregation at low density ratios and intensifies segregation at high density ratios. This behavior is associated with floc formation and vortex structures. These segregation characteristics provide valuable insights into the directional recovery of heavy metal particles from wastewater. Furthermore, involving cohesion promotes the horizontal dispersion of particles by influencing the vortex structure. It contributes to a better understanding of particle dispersion in aquatic environments and providing guidance for the use of flocculants in engineering applications.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"457 ","pages":"Article 120912"},"PeriodicalIF":4.5,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143686386","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-17DOI: 10.1016/j.powtec.2025.120931
Michael W. Stocker , Anne Marie Healy , Steven Ferguson
Solidification of room temperature ionic liquids provides advantages in terms of handling and utilisation in the context of solid dosage forms. Encapsulating drug-based ionic liquids by direct spray operations represents a promising platform for solidifying and formulating these challenging materials. Previous studies have focused on solidification of room temperature active pharmaceutical ingredient (API) ionic liquids (API-ILs) by spray drying. This approach typically results in the production of fine powders that tend to require further processing before they can be incorporated into final solid dosage forms. Fluidised bed granulation is an alternative technology that combines a direct spray operation with a particle size enlargement process. Successfully encapsulating an API-IL using this approach would circumvent suboptimal bulk powder properties of spray dried materials associated with their fine particle size and poor flowability, with the possibility of coating the granular cores with controlled release polymers and blending with additional excipients to yield a highly engineered drug product suitable for direct compression. In the current work a model API-IL was successfully granulated by adapting the spray encapsulation process to operate in a fluidised bed granulator and incorporating an inert filler material in the granulated product. The spray granulated API-IL products from this process were characterised with regard to their particle size, composition, and powder flow properties, and preliminary tabletting studies were performed using the granulates. This is the first demonstrated example of a composite drug product of its kind.
{"title":"A fluidised bed particle engineering approach for simultaneous encapsulation and granulation of an API-based ionic liquid","authors":"Michael W. Stocker , Anne Marie Healy , Steven Ferguson","doi":"10.1016/j.powtec.2025.120931","DOIUrl":"10.1016/j.powtec.2025.120931","url":null,"abstract":"<div><div>Solidification of room temperature ionic liquids provides advantages in terms of handling and utilisation in the context of solid dosage forms. Encapsulating drug-based ionic liquids by direct spray operations represents a promising platform for solidifying and formulating these challenging materials. Previous studies have focused on solidification of room temperature active pharmaceutical ingredient (API) ionic liquids (API-ILs) by spray drying. This approach typically results in the production of fine powders that tend to require further processing before they can be incorporated into final solid dosage forms. Fluidised bed granulation is an alternative technology that combines a direct spray operation with a particle size enlargement process. Successfully encapsulating an API-IL using this approach would circumvent suboptimal bulk powder properties of spray dried materials associated with their fine particle size and poor flowability, with the possibility of coating the granular cores with controlled release polymers and blending with additional excipients to yield a highly engineered drug product suitable for direct compression. In the current work a model API-IL was successfully granulated by adapting the spray encapsulation process to operate in a fluidised bed granulator and incorporating an inert filler material in the granulated product. The spray granulated API-IL products from this process were characterised with regard to their particle size, composition, and powder flow properties, and preliminary tabletting studies were performed using the granulates. This is the first demonstrated example of a composite drug product of its kind.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"457 ","pages":"Article 120931"},"PeriodicalIF":4.5,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143686387","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-17DOI: 10.1016/j.powtec.2025.120937
Jun Xie, Lijuan Hou, Qiang Ma, Yanchen Li, Jinlin Bian, Rundong Li
Coal, as a principal fossil energy source, occupies a crucial role in the global energy landscape. Nevertheless, the fine particles generated during the combustion of coal have exerted severe negative influences on human health, air visibility, and equipment safety. This paper focuses on wet flue gas desulfurization and collaborative dust removal technology as the research context. High-speed photography technology was employed to record the motion behavior of silica (SiO2) particles impacting deionized water, thereby the suspension/sinking phase diagram of the particles was obtained, and a fitting relationship between the particle size and the critical sinking velocity was established. The relationship was employed as the boundary condition and integrated with the Discrete Phase Model (DPM) in Computational Fluid Dynamics (CFD), and then the capture efficiency of micron-sized particles depositing onto the surface of liquid droplets was studied quantitatively. Moreover, the deposition distribution was explored by developing User Defined Functions (UDF). Finally, the influence of parameters such as particle sphericity, droplet diameter, airflow velocity, temperature difference, and droplet deformation rate on the capture efficiency, deposition distribution, and capture mechanism was elucidated, thereby providing theoretical support for the efficient removal of fine particles.
{"title":"Experimental and simulation studies on the capture of micro-particles by a single droplet","authors":"Jun Xie, Lijuan Hou, Qiang Ma, Yanchen Li, Jinlin Bian, Rundong Li","doi":"10.1016/j.powtec.2025.120937","DOIUrl":"10.1016/j.powtec.2025.120937","url":null,"abstract":"<div><div>Coal, as a principal fossil energy source, occupies a crucial role in the global energy landscape. Nevertheless, the fine particles generated during the combustion of coal have exerted severe negative influences on human health, air visibility, and equipment safety. This paper focuses on wet flue gas desulfurization and collaborative dust removal technology as the research context. High-speed photography technology was employed to record the motion behavior of silica (SiO<sub>2</sub>) particles impacting deionized water, thereby the suspension/sinking phase diagram of the particles was obtained, and a fitting relationship between the particle size and the critical sinking velocity was established. The relationship was employed as the boundary condition and integrated with the Discrete Phase Model (DPM) in Computational Fluid Dynamics (CFD), and then the capture efficiency of micron-sized particles depositing onto the surface of liquid droplets was studied quantitatively. Moreover, the deposition distribution was explored by developing User Defined Functions (UDF). Finally, the influence of parameters such as particle sphericity, droplet diameter, airflow velocity, temperature difference, and droplet deformation rate on the capture efficiency, deposition distribution, and capture mechanism was elucidated, thereby providing theoretical support for the efficient removal of fine particles.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"457 ","pages":"Article 120937"},"PeriodicalIF":4.5,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143686388","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-16DOI: 10.1016/j.powtec.2025.120935
Jie Mao , Nan Ye , Zichun Wu , Ziyi Gong , Haiou Zhuo , Wentan Zhu , Jiancheng Tang
Developing spherical W-Cu composite powders offers a promising solution for achieving additive manufacturing to prepare W-Cu composites with finer microstructures and superior properties. However, the melting point difference and poor wettability of W and Cu hinder traditional powder preparation methods. Spray drying with sintering densification provides an efficient, cost-effective, and eco-friendly approach to producing dense spherical powders for additive manufacturing. This study developed spherical W-Cu composite powders for additive manufacturing using WO3 and CuO as raw materials. Initially, a spherical W-Cu precursor powder was synthesized from WO3 and CuO via spray-drying granulation. The precursor powder was then subjected to a three-stage reduction procedure. Finally, high-performance powders were produced via cold isostatic pressing and high-temperature sintering with ultrafine WO3 as the sintering barrier. The resulting powders exhibited high sphericity, good dispersion, high densification, and fine-grained microstructures with uniform elemental distribution, as well as excellent fluidity (11.6 s/50 g), high loose apparent density (7.65 g/cm3), and low oxygen content (225 ppm), rendering them ideal for additive manufacturing. Laser-directed energy deposition (L-DED)-fabricated parts exhibited outstanding properties, including high densification (relative density 96.2 %), excellent tensile strength (512.57 MPa), hardness (260.6 HV0.5), electrical conductivity (37.93 % IACS), and thermal conductivity (215.35 W/mK), comparable to the W-Cu parts produced using conventional processes. The proposed method offers a promising approach for the development of advanced materials tailored to AM technologies.
{"title":"High-performance spherical W-Cu composite powders for additive manufacturing via spray granulation and cold isostatic pressure sintering","authors":"Jie Mao , Nan Ye , Zichun Wu , Ziyi Gong , Haiou Zhuo , Wentan Zhu , Jiancheng Tang","doi":"10.1016/j.powtec.2025.120935","DOIUrl":"10.1016/j.powtec.2025.120935","url":null,"abstract":"<div><div>Developing spherical W-Cu composite powders offers a promising solution for achieving additive manufacturing to prepare W-Cu composites with finer microstructures and superior properties. However, the melting point difference and poor wettability of W and Cu hinder traditional powder preparation methods. Spray drying with sintering densification provides an efficient, cost-effective, and eco-friendly approach to producing dense spherical powders for additive manufacturing. This study developed spherical W-Cu composite powders for additive manufacturing using WO<sub>3</sub> and CuO as raw materials. Initially, a spherical W-Cu precursor powder was synthesized from WO<sub>3</sub> and CuO via spray-drying granulation. The precursor powder was then subjected to a three-stage reduction procedure. Finally, high-performance powders were produced via cold isostatic pressing and high-temperature sintering with ultrafine WO<sub>3</sub> as the sintering barrier. The resulting powders exhibited high sphericity, good dispersion, high densification, and fine-grained microstructures with uniform elemental distribution, as well as excellent fluidity (11.6 s/50 g), high loose apparent density (7.65 g/cm<sup>3</sup>), and low oxygen content (225 ppm), rendering them ideal for additive manufacturing. Laser-directed energy deposition (L-DED)-fabricated parts exhibited outstanding properties, including high densification (relative density 96.2 %), excellent tensile strength (512.57 MPa), hardness (260.6 HV<sub>0.5</sub>), electrical conductivity (37.93 % IACS), and thermal conductivity (215.35 W/mK), comparable to the W-Cu parts produced using conventional processes. The proposed method offers a promising approach for the development of advanced materials tailored to AM technologies.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"457 ","pages":"Article 120935"},"PeriodicalIF":4.5,"publicationDate":"2025-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143687460","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Particle density is a fundamental and important physical property of powders. However, the widely used gas displacement pycnometry (GDP) method typically requires sample volumes in the gram range. In this study, we developed a method for evaluating the density of milligram-scale samples using X-ray computed tomography (XRCT). We used pharmaceutical powders, consisting of organic and light metallic elements, as subjects. The volumes of 24 pharmaceutical powders (2–160 mg) with various particle sizes and shapes were measured using an XRCT device with a resolution of 0.65–2.6 μm (field of view: 1.33–5.32 mm). Copper and molybdenum targets were used as X-ray sources, providing high-contrast imaging for materials with low electron densities. The densities obtained using XRCT correlated well with those obtained using GDP, as indicated by a linear regression line with a slope of 1.0 passing through the origin. The coefficient of variation for six sequential measurements was 0.0070, suggesting high repeatability. Additionally, we investigated optimal experimental conditions, such as spatial resolution, X-ray sources, and measurement time, to enhance the quality of three-dimensional XRCT images. We found that images with a grayscale histogram peak separation of approximately one between the sample and other components (sample tube and air) yielded optimal results. This non-destructive technique has the potential to accurately measure the densities of small sample quantities and can contribute not only to the pharmaceutical field but also to other industries handling organic and light metallic powders.
{"title":"Measurement of the particle density of small amounts of pharmaceutical powders using high-contrast micro X-ray computed tomography","authors":"Tamaki Miyazaki , Yoshihiro Takeda , Daisuke Ando , Tatsuo Koide , Yoji Sato , Eiichi Yamamoto","doi":"10.1016/j.powtec.2025.120929","DOIUrl":"10.1016/j.powtec.2025.120929","url":null,"abstract":"<div><div>Particle density is a fundamental and important physical property of powders. However, the widely used gas displacement pycnometry (GDP) method typically requires sample volumes in the gram range. In this study, we developed a method for evaluating the density of milligram-scale samples using X-ray computed tomography (XRCT). We used pharmaceutical powders, consisting of organic and light metallic elements, as subjects. The volumes of 24 pharmaceutical powders (2–160 mg) with various particle sizes and shapes were measured using an XRCT device with a resolution of 0.65–2.6 μm (field of view: 1.33–5.32 mm). Copper and molybdenum targets were used as X-ray sources, providing high-contrast imaging for materials with low electron densities. The densities obtained using XRCT correlated well with those obtained using GDP, as indicated by a linear regression line with a slope of 1.0 passing through the origin. The coefficient of variation for six sequential measurements was 0.0070, suggesting high repeatability. Additionally, we investigated optimal experimental conditions, such as spatial resolution, X-ray sources, and measurement time, to enhance the quality of three-dimensional XRCT images. We found that images with a grayscale histogram peak separation of approximately one between the sample and other components (sample tube and air) yielded optimal results. This non-destructive technique has the potential to accurately measure the densities of small sample quantities and can contribute not only to the pharmaceutical field but also to other industries handling organic and light metallic powders.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"457 ","pages":"Article 120929"},"PeriodicalIF":4.5,"publicationDate":"2025-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143687410","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-15DOI: 10.1016/j.powtec.2025.120936
Ce Zhang , Hanlin Wang , Rui Liu , Jiazhen Zhang , Xin Lu
In this work, a novel low-cost blend powder system including spherical Ti powder, irregular TiAl3 powder, and TiH2 powder is used to prepare MIM Ti48Al alloy. The optimum powder loading of the blend powder reaches 59 %, which is essentially equivalent as pre-alloyed spherical powder. The viscosity of feedstock using this powder system meets the requirement of injection molding operation. By including a suitable quantity of ultrafine TiH2 powder, the sinterability is greatly enhanced, resulting in a relative density above 98 % at a temperature of 1350 °C when the addition ratio is 4.5–9 wt%. The microstructure evolution at different sintering temperatures is also studied in detail. The original TiAl3 particles undergo a transformation into the γ phase, whereas the Ti powder particles ultimately form α2 + γ lamellar colonies. As the sintering temperature increases, the lamellar colonies grow and merge to form near- lamellar and full- lamellar structure.
{"title":"Study on sintering density and microstructure of metal injection molding of TiAl alloy using a new blend powder combination","authors":"Ce Zhang , Hanlin Wang , Rui Liu , Jiazhen Zhang , Xin Lu","doi":"10.1016/j.powtec.2025.120936","DOIUrl":"10.1016/j.powtec.2025.120936","url":null,"abstract":"<div><div>In this work, a novel low-cost blend powder system including spherical Ti powder, irregular TiAl<sub>3</sub> powder, and TiH<sub>2</sub> powder is used to prepare MIM Ti<img>48Al alloy. The optimum powder loading of the blend powder reaches 59 %, which is essentially equivalent as pre-alloyed spherical powder. The viscosity of feedstock using this powder system meets the requirement of injection molding operation. By including a suitable quantity of ultrafine TiH<sub>2</sub> powder, the sinterability is greatly enhanced, resulting in a relative density above 98 % at a temperature of 1350 °C when the addition ratio is 4.5–9 wt%. The microstructure evolution at different sintering temperatures is also studied in detail. The original TiAl<sub>3</sub> particles undergo a transformation into the γ phase, whereas the Ti powder particles ultimately form α<sub>2</sub> + γ lamellar colonies. As the sintering temperature increases, the lamellar colonies grow and merge to form near- lamellar and full- lamellar structure.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"457 ","pages":"Article 120936"},"PeriodicalIF":4.5,"publicationDate":"2025-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143687453","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-15DOI: 10.1016/j.powtec.2025.120919
Santiago Garrido Nuñez , Dingena L. Schott , Johan T. Padding
High-energy ball milling is a versatile method utilized in mechanochemical reactions and material transformations. Understanding and characterizing the relevant mechanical variables is crucial for the optimization and up-scaling of these processes. To achieve this, the present study delves into differentiating the contributions of normal and tangential interactions during high-energy collisions. Using Discrete Element Method (DEM) simulations, we characterize how operational parameters influence these energy dissipation modes, emphasizing the significance of tangential interactions. Our analysis also reveals how different operational parameters such as ball size, fill ratio, and rotational speed affect the mechanical action inside the milling jar giving rise to multiple operating zones where different modes of energy dissipation can thrive. Finally, we present master curves that generalize findings across a wide range of configurations, offering a tool for characterizing and predicting mechanochemical processes beyond the presented cases. These results provide a robust framework for improving mechanochemical reaction efficiency, and equipment design.
{"title":"Predictive models for energy dissipation in mechanochemical ball milling","authors":"Santiago Garrido Nuñez , Dingena L. Schott , Johan T. Padding","doi":"10.1016/j.powtec.2025.120919","DOIUrl":"10.1016/j.powtec.2025.120919","url":null,"abstract":"<div><div>High-energy ball milling is a versatile method utilized in mechanochemical reactions and material transformations. Understanding and characterizing the relevant mechanical variables is crucial for the optimization and up-scaling of these processes. To achieve this, the present study delves into differentiating the contributions of normal and tangential interactions during high-energy collisions. Using Discrete Element Method (DEM) simulations, we characterize how operational parameters influence these energy dissipation modes, emphasizing the significance of tangential interactions. Our analysis also reveals how different operational parameters such as ball size, fill ratio, and rotational speed affect the mechanical action inside the milling jar giving rise to multiple operating zones where different modes of energy dissipation can thrive. Finally, we present master curves that generalize findings across a wide range of configurations, offering a tool for characterizing and predicting mechanochemical processes beyond the presented cases. These results provide a robust framework for improving mechanochemical reaction efficiency, and equipment design.</div></div>","PeriodicalId":407,"journal":{"name":"Powder Technology","volume":"457 ","pages":"Article 120919"},"PeriodicalIF":4.5,"publicationDate":"2025-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143687459","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-15DOI: 10.1016/j.powtec.2025.120932
Yan Hu , Jincheng Zhang , Youyu Liu , Bowen Wu , Jiabao Pan
Suction multiphase jet machining (MJM) technology is a particulate erosion machining process utilizing vacuum to entrain slurry, wherein the motive tube is a pivotal unit that determines the jet nozzle performances. This paper presented an innovative MJM nozzle design featuring a Laval-shape motive tube, as well as the other three shapes: cylindrical, convergent and convergent-cylindrical. The work focused on investigating and comparing the performances of jet nozzles equipped with different motive tubes by experiments and simulations. It is found that the nozzle equipped with Laval-shape motive tube could generate the strongest vacuum while sucking the least slurry mixture, whereas these for nozzles equipped with cylindrical or convergent-cylindrical motive tube were opposite. The use of nozzle with Laval-shape motive tube was beneficial for rapid material removal owing to large velocity, enabling the fast machining of deep features, whereas the use of nozzles with cylindrical or convergent-cylindrical motive tube promoted the material's micro-removal to afford a relatively smooth surface. The significance of this work is that these findings are expected to provide a general guideline for MJM nozzle design and application.
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