Cardiovascular disease is the leading cause of human mortality,and calcified tissue blocking blood vessels is the main cause of major adverse cardiovascular events(MACE).Rotational Atherectomy(RA)is a minimally invasi...Cardiovascular disease is the leading cause of human mortality,and calcified tissue blocking blood vessels is the main cause of major adverse cardiovascular events(MACE).Rotational Atherectomy(RA)is a minimally invasive catheterbased treatment method that involves high-speed cutting of calcified tissue using miniature tools for removal.However,the cutting forces,heat,and debris can induce tissue damage and give rise to serious surgical complications.To enhance the effectiveness and efficiency of RA,a novel eccentric rotational cutting tool,with one side comprising axial and circumferential staggered micro-blades,was designed and fabricated in this study.In addition,a series of experiments were conducted to analyze their performance across five dimensions:tool kinematics,force,temperature,debris,and surface morphology of the specimens.Experimental results show that the force,temperature and debris size of the novel tool were well inhibited at the highest rotational speed.For the tool of standard clinical size(diameter 1.25 mm),the maximum force is 0.75 N,with a maximum temperature rise in the operation area of 1.09℃.Debris distribution followed a normal distribution pattern,with 90%of debris measuring smaller than 9.12μm.All tool metrics met clinical safety requirements,indicating its superior performance.This study provides a new idea for the design of calcified tissue removal tools,and contributes positively to the advancement of RA.展开更多
An advanced ceramic cutting tool material Al2O3/TiC/TiN （LTN） is developed by incorporation and dispersion of micro-scale TiC particle and nano-scale TiN particle in alumina matrix. With the optimal dispersing and f...An advanced ceramic cutting tool material Al2O3/TiC/TiN （LTN） is developed by incorporation and dispersion of micro-scale TiC particle and nano-scale TiN particle in alumina matrix. With the optimal dispersing and fabricating technology, this multi-scale and multi-phase nanocomposite ceramic tool material can get both higher flexural strength and fracture toughness than that of A1203/TiC （LZ） ceramic tool material without nano-scale TiN particle, especially the fracture toughness can reach to 7.8 MPa . m^0.5. The nano-scale TiN can lead to the grain fining effect and promote the sintering process to get a higher density. The coexisting transgranular and intergranular fracture mode induced by micro-scale TiC and nano-scale TiN, and the homogeneous and densified microstructure can result in a remarkable strengthening and toughening effect. The cutting performance and wear mechanisms of the advanced multi-scale and multi-phase nanocomposite ceramic cutting tool are researched.展开更多
This paper reports a Study carried out to substantiate or refute the belief that when coolant is applied, the cutting performance is actually improved. Experiments on cutting forces and chip geometry were conducted in...This paper reports a Study carried out to substantiate or refute the belief that when coolant is applied, the cutting performance is actually improved. Experiments on cutting forces and chip geometry were conducted in which AISI 1050 Steel was machined by turning using P30 uncoated tungsten carbide tools. Experiments were performed on a CNC Okuma LH35-N lathe undermachining conditions commonly used in workshops in Singapore and many other parts of the world.展开更多
Abrasiveness as an intrinsic property of rocks defines the extent of wear or loss when interacting with other materials.In engineering sectors like hard rock mining and tunnelling,comprehending rock abrasiveness holds...Abrasiveness as an intrinsic property of rocks defines the extent of wear or loss when interacting with other materials.In engineering sectors like hard rock mining and tunnelling,comprehending rock abrasiveness holds paramount importance due to its direct effect on tool wear during excavation.Among the diverse methods for assessing rock abrasiveness,the Cerchar abrasivity test emerges as the most widely used approach.Over time,the Cerchar test has garnered substantial attention from scholars,who have delved into the factors influencing test results due to testing conditions and examined the connection between the physical-mechanical parameters of rocks and their abrasiveness.Recent advancements in testing instrument have expanded our ability to measure additional parameters during rock cutting or drilling,yielding fresh insights for abrasiveness assessment,tool wear prediction,tool performance evaluation and rock excavatability estimation.The Cerchar abrasivity test,coupled with recent developments in testing instrument and parameter measurement,holds promising potential for enhancing our comprehension of rock abrasiveness and its practical implications.This review systematically traces the evolution of the test.It commences with an overview of the test origin and progression,emphasizing its pivotal role in assessing rock abrasiveness.Furthermore,it consolidates and categorizes the research contributions from various scholars regarding the test.This includes enhancements and refinements of the testing apparatus,as well as investigations into various testing orientations and their effects on different types of rocks.Moreover,this review illuminates the broader applications and interdisciplinary possibilities of this test,not only in material science but also in tribology.It underscores how the insights gleaned from the Cerchar test can be extrapolated to diverse areas of research beyond the scope of rock engineering.展开更多
Based on the results of slot milling experiments on the DD5 Ni-based single crystal superalloy(001) crystal plane along the [110]crystal direction, in this paper, efforts were devoted to investigate the tool wear proc...Based on the results of slot milling experiments on the DD5 Ni-based single crystal superalloy(001) crystal plane along the [110]crystal direction, in this paper, efforts were devoted to investigate the tool wear process, wear mechanism and failure modes of the physical vapor deposition(PVD)-AlTiN and TiAlN coated tools under dry milling and water-based minimum quantity lubrication(MQL) conditions. The scanning electron microscope(SEM) morphological observation and energy dispersive X-ray spectroscopy(EDX) elements analysis methods were adopted. Moreover, under the water-based MQL condition, the surface integrity such as surface roughness, dimensional and shape accuracy, microhardness and microstructure alteration were researched. The results demonstrated that the tool edge severe adhesion with the work material, induced by the high Al content in the PVD-AlTiN coating caused the catastrophic tool tip fracture. In contrast, the PVD-TiAlN tool displayed a steady and uniform minor flank wear, even though the material peeling and slight chipping also occurred in the final stage. In addition, due to the high effective cooling and lubricating actions of the water-based MQL method, the PVD-TiAlN coated tool demonstrated intact tip geometry; consequently it could be repaired and reused even if the failure criterion was attained. Moreover, as the accumulative milling length and the tool wear increased, all indicators of the surface integrity forehand were deteriorated.展开更多
The increasingly frequent exchange of performance data in grid systems across heterogeneous platforms requires a uniform 搑epresentation?of various types of performance data. This paper reviews the current related res...The increasingly frequent exchange of performance data in grid systems across heterogeneous platforms requires a uniform 搑epresentation?of various types of performance data. This paper reviews the current related research, considers the defect of existing methods, and proposes a new portable description method: grid performance data description (GPDD) using an extensible markup language (XML)-based grid performance data representation language (XGPDRL). GPDD describes the abstract structure, which has excellent extensibility (all types of performance data can be described in one format), efficiency, and flexibil-ity. XGPDRL defines the grammar of the GPDD performance data representation, and is both extensible and portable. For benchmarking purposes, performance data can be collected during runtime, represented in XGPDRL, and analyzed visually using a browser across heterogeneous platforms. GPDD and XGPDRL can conveniently ensure data comprehension across various platforms, and are very suitable for grid per-formance data representation.展开更多
Edge preparation can remove cutting edge defects,such as burrs,chippings,and grinding marks,generated in the grinding process and improve the cutting performance and service life of tools.Various edge preparation meth...Edge preparation can remove cutting edge defects,such as burrs,chippings,and grinding marks,generated in the grinding process and improve the cutting performance and service life of tools.Various edge preparation methods have been proposed for different tool matrix materials,geometries,and application requirements.This study presents a scientific and systematic review of the development of tool edge preparation technology and provides ideas for its future development.First,typical edge characterization methods,which associate the microgeometric characteristics of the cutting edge with cutting performance,are briefly introduced.Then,edge preparation methods for cutting tools,in which materials at the cutting edge area are removed to decrease defects and obtain a suitable microgeometry of the cutting edge for machining,are discussed.New edge preparation methods are explored on the basis of existing processing technologies,and the principles,advantages,and limitations of these methods are systematically summarized and analyzed.Edge preparation methods are classified into two categories:mechanical processing methods and nontraditional processing methods.These methods are compared from the aspects of edge consistency,surface quality,efficiency,processing difficulty,machining cost,and general availability.In this manner,a more intuitive understanding of the characteristics can be gained.Finally,the future development direction of tool edge preparation technology is prospected.展开更多
基金Supported by National Natural Science Foundation of China(Grant No.52205455)Fujian Provincial Health Technology Project(Grant Nos.2022CXA005,2022CXA015)。
文摘Cardiovascular disease is the leading cause of human mortality,and calcified tissue blocking blood vessels is the main cause of major adverse cardiovascular events(MACE).Rotational Atherectomy(RA)is a minimally invasive catheterbased treatment method that involves high-speed cutting of calcified tissue using miniature tools for removal.However,the cutting forces,heat,and debris can induce tissue damage and give rise to serious surgical complications.To enhance the effectiveness and efficiency of RA,a novel eccentric rotational cutting tool,with one side comprising axial and circumferential staggered micro-blades,was designed and fabricated in this study.In addition,a series of experiments were conducted to analyze their performance across five dimensions:tool kinematics,force,temperature,debris,and surface morphology of the specimens.Experimental results show that the force,temperature and debris size of the novel tool were well inhibited at the highest rotational speed.For the tool of standard clinical size(diameter 1.25 mm),the maximum force is 0.75 N,with a maximum temperature rise in the operation area of 1.09℃.Debris distribution followed a normal distribution pattern,with 90%of debris measuring smaller than 9.12μm.All tool metrics met clinical safety requirements,indicating its superior performance.This study provides a new idea for the design of calcified tissue removal tools,and contributes positively to the advancement of RA.
基金Selected from Proceedings of the 7th International Conference on Frontiers of DesignManufacturing(ICFDM'2006)This project is supported by National Natural Science Foundation of China(No.50275086)the University of New South Wales Visiting Professorship Scheme,Australia.
文摘An advanced ceramic cutting tool material Al2O3/TiC/TiN （LTN） is developed by incorporation and dispersion of micro-scale TiC particle and nano-scale TiN particle in alumina matrix. With the optimal dispersing and fabricating technology, this multi-scale and multi-phase nanocomposite ceramic tool material can get both higher flexural strength and fracture toughness than that of A1203/TiC （LZ） ceramic tool material without nano-scale TiN particle, especially the fracture toughness can reach to 7.8 MPa . m^0.5. The nano-scale TiN can lead to the grain fining effect and promote the sintering process to get a higher density. The coexisting transgranular and intergranular fracture mode induced by micro-scale TiC and nano-scale TiN, and the homogeneous and densified microstructure can result in a remarkable strengthening and toughening effect. The cutting performance and wear mechanisms of the advanced multi-scale and multi-phase nanocomposite ceramic cutting tool are researched.
文摘This paper reports a Study carried out to substantiate or refute the belief that when coolant is applied, the cutting performance is actually improved. Experiments on cutting forces and chip geometry were conducted in which AISI 1050 Steel was machined by turning using P30 uncoated tungsten carbide tools. Experiments were performed on a CNC Okuma LH35-N lathe undermachining conditions commonly used in workshops in Singapore and many other parts of the world.
文摘Abrasiveness as an intrinsic property of rocks defines the extent of wear or loss when interacting with other materials.In engineering sectors like hard rock mining and tunnelling,comprehending rock abrasiveness holds paramount importance due to its direct effect on tool wear during excavation.Among the diverse methods for assessing rock abrasiveness,the Cerchar abrasivity test emerges as the most widely used approach.Over time,the Cerchar test has garnered substantial attention from scholars,who have delved into the factors influencing test results due to testing conditions and examined the connection between the physical-mechanical parameters of rocks and their abrasiveness.Recent advancements in testing instrument have expanded our ability to measure additional parameters during rock cutting or drilling,yielding fresh insights for abrasiveness assessment,tool wear prediction,tool performance evaluation and rock excavatability estimation.The Cerchar abrasivity test,coupled with recent developments in testing instrument and parameter measurement,holds promising potential for enhancing our comprehension of rock abrasiveness and its practical implications.This review systematically traces the evolution of the test.It commences with an overview of the test origin and progression,emphasizing its pivotal role in assessing rock abrasiveness.Furthermore,it consolidates and categorizes the research contributions from various scholars regarding the test.This includes enhancements and refinements of the testing apparatus,as well as investigations into various testing orientations and their effects on different types of rocks.Moreover,this review illuminates the broader applications and interdisciplinary possibilities of this test,not only in material science but also in tribology.It underscores how the insights gleaned from the Cerchar test can be extrapolated to diverse areas of research beyond the scope of rock engineering.
基金supported by the National Natural Science Foundation of China(Grant No.51375082)
文摘Based on the results of slot milling experiments on the DD5 Ni-based single crystal superalloy(001) crystal plane along the [110]crystal direction, in this paper, efforts were devoted to investigate the tool wear process, wear mechanism and failure modes of the physical vapor deposition(PVD)-AlTiN and TiAlN coated tools under dry milling and water-based minimum quantity lubrication(MQL) conditions. The scanning electron microscope(SEM) morphological observation and energy dispersive X-ray spectroscopy(EDX) elements analysis methods were adopted. Moreover, under the water-based MQL condition, the surface integrity such as surface roughness, dimensional and shape accuracy, microhardness and microstructure alteration were researched. The results demonstrated that the tool edge severe adhesion with the work material, induced by the high Al content in the PVD-AlTiN coating caused the catastrophic tool tip fracture. In contrast, the PVD-TiAlN tool displayed a steady and uniform minor flank wear, even though the material peeling and slight chipping also occurred in the final stage. In addition, due to the high effective cooling and lubricating actions of the water-based MQL method, the PVD-TiAlN coated tool demonstrated intact tip geometry; consequently it could be repaired and reused even if the failure criterion was attained. Moreover, as the accumulative milling length and the tool wear increased, all indicators of the surface integrity forehand were deteriorated.
基金the National High-Tech Research and Devel-opment (863) Program of China (No. 2002AA104230)
文摘The increasingly frequent exchange of performance data in grid systems across heterogeneous platforms requires a uniform 搑epresentation?of various types of performance data. This paper reviews the current related research, considers the defect of existing methods, and proposes a new portable description method: grid performance data description (GPDD) using an extensible markup language (XML)-based grid performance data representation language (XGPDRL). GPDD describes the abstract structure, which has excellent extensibility (all types of performance data can be described in one format), efficiency, and flexibil-ity. XGPDRL defines the grammar of the GPDD performance data representation, and is both extensible and portable. For benchmarking purposes, performance data can be collected during runtime, represented in XGPDRL, and analyzed visually using a browser across heterogeneous platforms. GPDD and XGPDRL can conveniently ensure data comprehension across various platforms, and are very suitable for grid per-formance data representation.
基金the National Natural Science Foundation of China(Grant No.52175441).
文摘Edge preparation can remove cutting edge defects,such as burrs,chippings,and grinding marks,generated in the grinding process and improve the cutting performance and service life of tools.Various edge preparation methods have been proposed for different tool matrix materials,geometries,and application requirements.This study presents a scientific and systematic review of the development of tool edge preparation technology and provides ideas for its future development.First,typical edge characterization methods,which associate the microgeometric characteristics of the cutting edge with cutting performance,are briefly introduced.Then,edge preparation methods for cutting tools,in which materials at the cutting edge area are removed to decrease defects and obtain a suitable microgeometry of the cutting edge for machining,are discussed.New edge preparation methods are explored on the basis of existing processing technologies,and the principles,advantages,and limitations of these methods are systematically summarized and analyzed.Edge preparation methods are classified into two categories:mechanical processing methods and nontraditional processing methods.These methods are compared from the aspects of edge consistency,surface quality,efficiency,processing difficulty,machining cost,and general availability.In this manner,a more intuitive understanding of the characteristics can be gained.Finally,the future development direction of tool edge preparation technology is prospected.
