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Products produced by additive manufacturing (AM) seek to exploit net shape manufacturing by eliminating or minimizing post-process stages such as machining. However, many applications which include turbo machinery components with tight dimensional tolerances and a smooth surface finish will require at least a light machine finishing stage. This paper investigates the machinability of the additively fabricated INCONEL718 (IN718) alloy produced by laser melting powder bed fusion (LM-PBF) with different levels of spherical porosity in the microstructure. The literature suggests that the band width for laser energy density, which combines the various scan process parameters to obtain a low spherical type porosity in the LM-PBF IN718 alloy (~1%), has wide breadth. With the increasing laser energy density and above a threshold, there is a rapid increase in the spherical pore size. In this paper, three tube samples each with different levels of spherical porosity were fabricated by varying the laser energy density for LM-PBF of the IN718 alloy within the stable and higher energy density range and the porosity measured. A low laser energy density was avoided due to balling up, which promotes highly irregular lack of fusion defects and poor consolidation within the alloy microstructure. An orthogonal turning test instrumented, with a three-component dynamometer to measure the cutting forces, was performed on AM produced IN718 tube samples under light cut conditions to simulate a finish machining process. The orthogonal turning tests were also performed on a tube sample obtained from the wrought extruded stock. The machining process parameters, which were studied include varying the cutting speed at three levels, at a fixed feed and under dry cut conditions for a short duration to avoid the tool wear. The results obtained were discussed and a notable finding was the higher rate of built-up-edge formation on the tool tip from the AM samples with a higher porosity and especially at a higher cutting speed. The paper also discusses the mechanisms that underpin the findings.
Paul Wood; Antonio Díaz-Álvarez; José. Díaz-Álvarez; María Henar Miguélez; Alexis Rusinek; Urvashi F. Gunputh; Gavin Williams; Slim Bahi; Judyta Sienkiewicz; Paweł Płatek. Machinability of INCONEL718 Alloy with a Porous Microstructure Produced by Laser Melting Powder Bed Fusion at Higher Energy Densities. Materials 2020, 13, 5730 .
AMA StylePaul Wood, Antonio Díaz-Álvarez, José. Díaz-Álvarez, María Henar Miguélez, Alexis Rusinek, Urvashi F. Gunputh, Gavin Williams, Slim Bahi, Judyta Sienkiewicz, Paweł Płatek. Machinability of INCONEL718 Alloy with a Porous Microstructure Produced by Laser Melting Powder Bed Fusion at Higher Energy Densities. Materials. 2020; 13 (24):5730.
Chicago/Turabian StylePaul Wood; Antonio Díaz-Álvarez; José. Díaz-Álvarez; María Henar Miguélez; Alexis Rusinek; Urvashi F. Gunputh; Gavin Williams; Slim Bahi; Judyta Sienkiewicz; Paweł Płatek. 2020. "Machinability of INCONEL718 Alloy with a Porous Microstructure Produced by Laser Melting Powder Bed Fusion at Higher Energy Densities." Materials 13, no. 24: 5730.
Induced damage during biocomposites drilling is significantly different to that produced on composites based on synthetic reinforcement such as carbon or glass fibers. In composites reinforced with carbon or glass fibers, induced damage increases with feed rate, however damage was observed to decrease with feed rate in biocomposites reinforced with natural fibers. This work is focused on the explanation of this differences between biocomposites and traditional composites based on the effect of strain rate on the material behavior during machining. A FEM model has been developed in ABAQUS/Explicit to verify this hypothesis. This numerical model has been used to explain the differences found between traditional composites and biocomposites in the influence of the main drilling parameters on induced damage during drilling. Experimental tests were conducted to validate the model through the comparison between thrust forces and damage factor for two different drills geometries on Flax/PLA bio composites. The results indicate that the decrease of induced damage with feed rate is only predicted when the constitutive model accounts for experimental behavior observed in this type of composites. Additionally, the numerical model demonstrated the ability to reproduce the effect of the different cutting conditions (cutting speed, feed, thickness and drill geometry) observed during experimental tests on induced damage during drilling.
A. Díaz-Álvarez; N. Feito; C. Santiuste. Drilling of biocomposite materials: Modelling and experimental validation. Simulation Modelling Practice and Theory 2020, 106, 102203 .
AMA StyleA. Díaz-Álvarez, N. Feito, C. Santiuste. Drilling of biocomposite materials: Modelling and experimental validation. Simulation Modelling Practice and Theory. 2020; 106 ():102203.
Chicago/Turabian StyleA. Díaz-Álvarez; N. Feito; C. Santiuste. 2020. "Drilling of biocomposite materials: Modelling and experimental validation." Simulation Modelling Practice and Theory 106, no. : 102203.
This work focuses on the combination of two complementary non-destructive techniques to analyse the final deformation and internal damage induced in aramid composite plates subjected to ballistic impact. The first analysis device, a 3D scanner, allows digitalising the surface of the tested specimen. Comparing with the initial geometry, the permanent residual deformation (PBFD) can be obtained according to the impact characteristics. This is a significant parameter in armours and shielding design. The second inspection technique is based on computed tomography (CT). It allows analysing the internal state of the impacted sample, being able to detect possible delamination and fibre failure through the specimen thickness. The proposed methodology has been validated with two projectile geometries at different impact velocities, being the reaction force history on the specimen determined with piezoelectric sensors. Different loading states and induced damages were observed according to the projectile type and impact velocity. In order to validate the use of the 3D scanner, a correlation between impact velocity and damage induced in terms of permanent back face deformation has been realised for both projectiles studied. In addition, a comparison of the results obtained through this measurement method and those obtained in similar works, has been performed in the same range of impact energy. The results showed that CT is needed to analyse the internal damage of the aramid sample; however, this is a highly expensive and time-consuming method. The use of 3D scanner and piezoelectric sensors is perfectly complementary with CT and could be relevant to develop numerical models or design armours.
Ignacio Rubio; Antonio Díaz-Álvarez; Richard Bernier; Alexis Rusinek; Jose Antonio Loya; Maria Henar Miguelez; Marcos Rodríguez-Millán. Postmortem Analysis Using Different Sensors and Technologies on Aramid Composites Samples after Ballistic Impact. Sensors 2020, 20, 2853 .
AMA StyleIgnacio Rubio, Antonio Díaz-Álvarez, Richard Bernier, Alexis Rusinek, Jose Antonio Loya, Maria Henar Miguelez, Marcos Rodríguez-Millán. Postmortem Analysis Using Different Sensors and Technologies on Aramid Composites Samples after Ballistic Impact. Sensors. 2020; 20 (10):2853.
Chicago/Turabian StyleIgnacio Rubio; Antonio Díaz-Álvarez; Richard Bernier; Alexis Rusinek; Jose Antonio Loya; Maria Henar Miguelez; Marcos Rodríguez-Millán. 2020. "Postmortem Analysis Using Different Sensors and Technologies on Aramid Composites Samples after Ballistic Impact." Sensors 20, no. 10: 2853.
Carbon Fiber-reinforced plastics (CFRPs) are widely used in the aerospace industry due to their highly mechanical properties and low density. Most of these materials are used in high-risk structures, where the damage caused by machining must be controlled and minimized. The optimization of these processes is still a challenge in the industry. In this work, a special cutting device, which allows for orthogonal cutting tests, with a linear displacement at a wide range of constant cutting speeds, has been developed by the authors. This paper describes the developed cutting device and its application to analyze the influence of tool geometry and cutting parameters on the material damage caused by the orthogonal cutting of a thick multidirectional CFRP laminate. The results show that a more robust geometry (higher cutting edge radius and lower rake angle) and higher feed cause an increase in the thrust force of a cutting tool, causing burrs and delamination damage. By reducing the cutting speed, the components with a higher machining force were also observed to have less surface integrity control.
Víctor Criado; Norberto Feito; José Luis Cantero Guisández; José Díaz-Álvarez. A New Cutting Device Design to Study the Orthogonal Cutting of CFRP Laminates at Different Cutting Speeds. Materials 2019, 12, 4074 .
AMA StyleVíctor Criado, Norberto Feito, José Luis Cantero Guisández, José Díaz-Álvarez. A New Cutting Device Design to Study the Orthogonal Cutting of CFRP Laminates at Different Cutting Speeds. Materials. 2019; 12 (24):4074.
Chicago/Turabian StyleVíctor Criado; Norberto Feito; José Luis Cantero Guisández; José Díaz-Álvarez. 2019. "A New Cutting Device Design to Study the Orthogonal Cutting of CFRP Laminates at Different Cutting Speeds." Materials 12, no. 24: 4074.
The use of 100% biodegradable composites in the industry is increasing significantly over the years, mainly due to their excellent properties as well as to the growing ecologic concern. However, after their manufacture, the composite pieces do not always have the final shape, requiring subsequent processing operations, usually drilling and trimming. The performance of cutting processes on fully biodegradable composites are often limited by induced damage as fraying and delamination. This type of phenomena is related, among others, with the cutting parameters and geometries of the tool. Orthogonal cutting is a simplified process that could help in the understanding of damage mechanisms, it is a well-known technique in traditional composites but its use in biocomposites is an almost unexplored field. This work focuses on flax/PLA 100% biodegradable woven composites. The specimens have been manufactured with different angles of orientation, ranging from 0° to 60°, being subjected to orthogonal cutting in a special machine developed for that purpose that allows to develop cutting tests with linear displacement at high speeds. Damage extension, failure modes, and cutting forces are analyzed allowing the extraction of important experimental information.
A. Díaz-Álvarez; J.L. Cantero; C. Santiuste. Analysis of orthogonal cutting of biocomposites. Composite Structures 2019, 234, 111734 .
AMA StyleA. Díaz-Álvarez, J.L. Cantero, C. Santiuste. Analysis of orthogonal cutting of biocomposites. Composite Structures. 2019; 234 ():111734.
Chicago/Turabian StyleA. Díaz-Álvarez; J.L. Cantero; C. Santiuste. 2019. "Analysis of orthogonal cutting of biocomposites." Composite Structures 234, no. : 111734.
Nickel-based superalloys exhibit an exceptional combination of corrosion resistance, enhanced mechanical properties at high temperatures, and thermal stability. The mechanical behavior of nickel-based superalloys depends on the grain size and the precipitation state after aging. Haynes 282 was developed in order to improve the creep behavior, formability, and strain-age cracking of the other commonly used nickel-based superalloys. Nevertheless, taking into account the interest of the industry in the machinability of Haynes 282 because of its great mechanical properties, which is not found in other superalloys like Inconel 718 or Waspaloy, more research on this alloy is necessary. Cutting tools suffer extreme thermomechanical loading because of the high pressure and temperature localized in the cutting zone. The consequence is material adhesion during machining and strong abrasion due to the hard carbides included in the material. The main recommendations for finishing turning in Haynes 282 include the use of carbide tools, low cutting speeds, low depth of pass, and the use of cutting fluids. However, because of the growing interest in sustainable processes and cost reduction, dry machining is considered to be one of the best techniques for material removal. During the machining of Haynes 282, at both the finishing and roughing turning, cemented carbide inserts are most commonly used and are recommended all over the industry. This paper deals with the machining of Haynes 282 by means of coated carbide tools cutting fluids (dry condition). Different cutting speeds and feeds were tested to quantify the cutting forces, quality of surface, wear progression, and end of tool life. Tool life values similar to those obtained with a lubricant under similar conditions in other studies have been obtained for the most favorable conditions in dry environments.
Antonio Díaz-Álvarez; José Díaz-Álvarez; José Luis Cantero; Henar Miguélez. Sustainable High-Speed Finishing Turning of Haynes 282 Using Carbide Tools in Dry Conditions. Metals 2019, 9, 989 .
AMA StyleAntonio Díaz-Álvarez, José Díaz-Álvarez, José Luis Cantero, Henar Miguélez. Sustainable High-Speed Finishing Turning of Haynes 282 Using Carbide Tools in Dry Conditions. Metals. 2019; 9 (9):989.
Chicago/Turabian StyleAntonio Díaz-Álvarez; José Díaz-Álvarez; José Luis Cantero; Henar Miguélez. 2019. "Sustainable High-Speed Finishing Turning of Haynes 282 Using Carbide Tools in Dry Conditions." Metals 9, no. 9: 989.
Local delamination is the most undesirable damage associated with drilling carbon fiber reinforced composite materials (CFRPs). This defect reduces the structural integrity of the material, which affects the residual strength of the assembled components. A positive correlation between delamination extension and thrust force during the drilling process is reported in literature. The abrasive effect of the carbon fibers modifies the geometry of the fresh tool, which increases the thrust force and, in consequence, the induced damage in the workpiece. Using a control system based on an artificial neural network (ANN), an analysis of the influence of the tool wear in the thrust force during the drilling of CFRP laminate to reduce the damage is developed. The spindle speed, feed rate, and drill point angle are also included as input parameters of the study. The training and testing of the ANN model are carried out with experimental drilling tests using uncoated carbide helicoidal tools. The data were trained using error-back propagation-training algorithm (EBPTA). The use of the neural network rapidly provides results of the thrust force evolution in function of the tool wear and cutting parameters. The obtained results can be used by the industry as a guide to control the impact of the wear of the tool in the quality of the finished workpiece.
Norberto Feito; Ana Muñoz-Sánchez; Antonio Díaz-Álvarez; José Antonio Loya. Analysis of the Machinability of Carbon Fiber Composite Materials in Function of Tool Wear and Cutting Parameters Using the Artificial Neural Network Approach. Materials 2019, 12, 2747 .
AMA StyleNorberto Feito, Ana Muñoz-Sánchez, Antonio Díaz-Álvarez, José Antonio Loya. Analysis of the Machinability of Carbon Fiber Composite Materials in Function of Tool Wear and Cutting Parameters Using the Artificial Neural Network Approach. Materials. 2019; 12 (17):2747.
Chicago/Turabian StyleNorberto Feito; Ana Muñoz-Sánchez; Antonio Díaz-Álvarez; José Antonio Loya. 2019. "Analysis of the Machinability of Carbon Fiber Composite Materials in Function of Tool Wear and Cutting Parameters Using the Artificial Neural Network Approach." Materials 12, no. 17: 2747.
This paper analyses the impact behavior of Inconel 718 through experimental and numerical approach. Different conical projectiles were tested in order to obtain the ballistic curves and failure mechanisms. A three-dimensional (3D) numerical model corresponding to the experimental tests was developed using the Johnson–Cook constitutive model. The experimental data (residual velocities, global, and local perforation mechanisms) were successfully predicted with the numerical simulations. The influence of the projectile’s nose angle was found to be important when designing ballistic protections. The projectile with the narrowest angle, 40°, developed a ballistic limit approximately 10 m/s lower than the projectile with a 72° nose. The use of double-nose projectile for the same nose angle, 72°, led to a ballistic limit 12 m/s lower than that obtained for the single nose.
Marcos Rodríguez-Millán; Antonio Díaz-Álvarez; Richard Bernier; María Henar Miguélez; José Antonio Loya; Rodríguez- Millán; Loya. Experimental and Numerical Analysis of Conical Projectile Impact on Inconel 718 Plates. Metals 2019, 9, 638 .
AMA StyleMarcos Rodríguez-Millán, Antonio Díaz-Álvarez, Richard Bernier, María Henar Miguélez, José Antonio Loya, Rodríguez- Millán, Loya. Experimental and Numerical Analysis of Conical Projectile Impact on Inconel 718 Plates. Metals. 2019; 9 (6):638.
Chicago/Turabian StyleMarcos Rodríguez-Millán; Antonio Díaz-Álvarez; Richard Bernier; María Henar Miguélez; José Antonio Loya; Rodríguez- Millán; Loya. 2019. "Experimental and Numerical Analysis of Conical Projectile Impact on Inconel 718 Plates." Metals 9, no. 6: 638.
Hybrid stack drilling is a very common operation used in the assembly of high-added-value components, which combines the use of composite materials and metallic alloys. This process entails the complexity of machining very dissimilar materials, simultaneously, on account of the interactions that are produced between them, during machining. This study analyzed the influence of Minimum Quantity Lubrication (MQL) on the performance of diamond-coated carbide tools when drilling Ti/carbon fiber reinforced plastics (CFRP)/Ti stacks. The main wear mechanism observed was diamond-coating detachment, followed by fragile breaks in the main cutting-edge. The tests done with the lower lubrication levels have shown an important adhesion of titanium (mainly on the secondary cutting-edge) and a higher friction between the tool and the workpiece, producing higher temperatures on the cutting region and a thermal softening effect on the workpiece. These phenomena affect the evolution of cutting power consumption with tool wear in the titanium layer. Regarding the quality of the test specimen, no significant differences were observed between the lubrication levels tested.
J. Fernández-Pérez; J. L. Cantero; J. Díaz-Álvarez; M. H. Miguélez. Hybrid Composite-Metal Stack Drilling with Different Minimum Quantity Lubrication Levels. Materials 2019, 12, 448 .
AMA StyleJ. Fernández-Pérez, J. L. Cantero, J. Díaz-Álvarez, M. H. Miguélez. Hybrid Composite-Metal Stack Drilling with Different Minimum Quantity Lubrication Levels. Materials. 2019; 12 (3):448.
Chicago/Turabian StyleJ. Fernández-Pérez; J. L. Cantero; J. Díaz-Álvarez; M. H. Miguélez. 2019. "Hybrid Composite-Metal Stack Drilling with Different Minimum Quantity Lubrication Levels." Materials 12, no. 3: 448.
Biocomposites are promising materials for traditional composites replacement in specific applications due to their interesting properties and sustainability. Although the composite components are manufactured near net shape, some machining operations, commonly drilling, are commonly required prior to mechanical joining of the components. Tool geometry, mainly the point angle of the drill, strongly affects the performance of the drilling process of composites in terms of machining induced damage. The aim of this work is analyzing the influence of the point angle of the drill on the damage generated during drilling of 100% biodegradable composite, using both numerical and experimental approaches. The novelty of the work relies on the lack of studies of drilling 100% biodegradable composites. The influence of the point angle on the thrust forces and hence in the machining induced damage was demonstrated.
José Díaz Álvarez; Carlos Santiuste; M.H. Miguélez. Experimental and numerical analysis of the influence of drill point angle when drilling biocomposites. Composite Structures 2018, 209, 700 -709.
AMA StyleJosé Díaz Álvarez, Carlos Santiuste, M.H. Miguélez. Experimental and numerical analysis of the influence of drill point angle when drilling biocomposites. Composite Structures. 2018; 209 ():700-709.
Chicago/Turabian StyleJosé Díaz Álvarez; Carlos Santiuste; M.H. Miguélez. 2018. "Experimental and numerical analysis of the influence of drill point angle when drilling biocomposites." Composite Structures 209, no. : 700-709.
In fatigue problems, an accurate estimation of the propagation direction is important for life prediction. We identify the most relevant factors that affect the crack orientation during the propagation stage of fretting fatigue cracks, arising from complete contacts. Contrary to what initially expected, parameters such as normal load, cyclic bulk load, etc. do not have a noticeable influence on the orientation. However the relative Young's moduli of indenter/specimen materials, the indenter width and the surface coefficient of friction are the most influencing factors. Analyses are performed through the extended finite element method (X-FEM) and an orientation criterion for non-proportional loading proposed by the authors. Experimental fretting fatigue tests confirm the predicted trends. An explanation of this behaviour is also given.
Miguel Marco; Diego Infante-Garcia; José Díaz Álvarez; Eugenio Giner. Relevant factors affecting the direction of crack propagation in complete contact problems under fretting fatigue. Tribology International 2018, 131, 343 -352.
AMA StyleMiguel Marco, Diego Infante-Garcia, José Díaz Álvarez, Eugenio Giner. Relevant factors affecting the direction of crack propagation in complete contact problems under fretting fatigue. Tribology International. 2018; 131 ():343-352.
Chicago/Turabian StyleMiguel Marco; Diego Infante-Garcia; José Díaz Álvarez; Eugenio Giner. 2018. "Relevant factors affecting the direction of crack propagation in complete contact problems under fretting fatigue." Tribology International 131, no. : 343-352.
Stab resistance is a crucial material property in the case of fabrics used in personal protection equipment due to the extensive occurrence of this threat. Personal Protection Equipments (PPE) are commonly based on woven aramids, where the stacking sequence is critical to improve the ratio between protection and weight. PPE should combine optimal penetration resistance with ergonomic requirements. This paper focuses on experimental characterisation of the stab protective efficiency of different architectures of aramid laminates. The influence of different stacking sequences, based on the combination of not treated (N) and thermoplastic aramids (TP), is analysed showing a significant influence of this factor. In the range of the impact energies analysed in this work, it can be concluded that the TP-N-TP sequence is the best choice for stabbing protection.
M. Rodríguez-Millán; Antonio Diaz; Josue Aranda-Ruiz; J.A. Loya. Experimental analysis for stabbing resistance of different aramid composite architectures. Composite Structures 2018, 208, 525 -534.
AMA StyleM. Rodríguez-Millán, Antonio Diaz, Josue Aranda-Ruiz, J.A. Loya. Experimental analysis for stabbing resistance of different aramid composite architectures. Composite Structures. 2018; 208 ():525-534.
Chicago/Turabian StyleM. Rodríguez-Millán; Antonio Diaz; Josue Aranda-Ruiz; J.A. Loya. 2018. "Experimental analysis for stabbing resistance of different aramid composite architectures." Composite Structures 208, no. : 525-534.
Nickel-based superalloys are widely used in the aeronautical industry, especially in components requiring excellent corrosion resistance, enhanced thermal fatigue properties, and thermal stability. Haynes 282 is a nickel-based superalloy that was developed to improve the low weldability, formability, and creep strength of other γ’-strengthened Ni superalloys. Despite the industrial interest in Haynes 282, there is a lack of research that is focused on this alloy. Moreover, it is difficult to find studies dealing with the machinability of Haynes 282. Although Haynes 282 is considered an alloy with improved formability when compared with other nickel alloys, its machining performance should be analyzed. High pressure and temperature localized in the cutting zone, the abrasion generated by the hard carbides included in the material, and the tendency toward adhesion during machining are phenomena that generate extreme thermomechanical loading on the tool during the cutting process. Excessive wear results in reduced tool life, leading to frequent tool change, low productivity, and a high consumption of energy; consequentially, there are increased costs. With regard to tool materials, cemented carbide tools are widely used in different applications, and carbide is a recommended cutting material for turning Haynes 282, for both finishing and roughing operations. This work focuses on the finishing turning of Haynes 282 using coated carbide tools with conventional coolant. Machining forces, surface roughness, tool wear, and tool life were quantified for different cutting speeds and feeds.
José Díaz-Álvarez; Antonio Díaz-Álvarez; Henar Miguélez; José Luis Cantero. Finishing Turning of Ni Superalloy Haynes 282. Metals 2018, 8, 843 .
AMA StyleJosé Díaz-Álvarez, Antonio Díaz-Álvarez, Henar Miguélez, José Luis Cantero. Finishing Turning of Ni Superalloy Haynes 282. Metals. 2018; 8 (10):843.
Chicago/Turabian StyleJosé Díaz-Álvarez; Antonio Díaz-Álvarez; Henar Miguélez; José Luis Cantero. 2018. "Finishing Turning of Ni Superalloy Haynes 282." Metals 8, no. 10: 843.
Aramid composites are increasingly used alone or combined with other composites in structural and personal protections due to the current demand of these applications against ballistic or fragment hazards. Drilling is a common operation required prior to mechanical joining of components, however this operation has been poorly analyzed in the case of aramid composites. Drilling induced damage of this family of composites is analyzed in the present work considering the effect of the drill geometry and cutting parameters. Fuzzing was the dominant damage mechanism both at hole entry and exit being also found delamination in most cases. Drill geometry and feed were influential parameters on resultant composite damage. Main contribution of this work is the obtainment of phenomelogical expressions derived from experimental data, allowing the prediction of damage extension as a function of cutting parameters.
Antonio Diaz; M. Rodríguez-Millán; M.H. Miguélez. Experimental analysis of drilling induced damage in aramid composites. Composite Structures 2018, 202, 1136 -1144.
AMA StyleAntonio Diaz, M. Rodríguez-Millán, M.H. Miguélez. Experimental analysis of drilling induced damage in aramid composites. Composite Structures. 2018; 202 ():1136-1144.
Chicago/Turabian StyleAntonio Diaz; M. Rodríguez-Millán; M.H. Miguélez. 2018. "Experimental analysis of drilling induced damage in aramid composites." Composite Structures 202, no. : 1136-1144.
Inconel 718 is a nickel-based superalloy widely used in the aerospace industry, nuclear plants and gas turbines due to the exceptional mechanical properties and resistance to corrosion at elevated temperature. For these reasons Inconel 718 have a low machinability due to the high temperatures that appear in the cutting area in addition to the wear caused in the tools as abrasion, chemical affinity, diffusion, flank and notch wear. Carbide and recently Polycrystalline Cubic Boron Nitride (PCBN), are the cutting tool materials used in finishing operations of nickel-based superalloys. This paper focuses on the comparative analysis of carbide and PCBN tools in finishing operations on Inconel 718 using cutting fluid at conventional pressure (7.5 bar). Experimental tests were performed at different cutting speeds, feed rate and depths of cut depending of the cutting tool. PCBN tools were used at speeds within the range of 250-300 m/min, feed between 0.1 and 0.15 mm/rev and depth of 0.15mm. Carbide tools are not used at such speeds because of their lower hardness at high temperature. Speeds five times lower than those were used for PCBN (50-70 m/min), the same feeds (between 0.1 and 0.15 mm/rev) and a depth of 0.25 mm were used. Tool life and machined surface has been analyzed with the aim of studying the viability of these tools in finishing conditions of Inconel 718. The results indicate that PCBN tools have a shorter life in minutes than carbide tools; however, the machined surface by cutting edge is larger at higher cutting speeds, so PCBN tools are an interesting alternative in this type of machining.
Víctor Criado; José Díaz-Álvarez; José Luis Cantero; María Henar Miguélez. Study of the performance of PCBN and carbide tools in finishing machining of Inconel 718 with cutting fluid at conventional pressures. Procedia CIRP 2018, 77, 634 -637.
AMA StyleVíctor Criado, José Díaz-Álvarez, José Luis Cantero, María Henar Miguélez. Study of the performance of PCBN and carbide tools in finishing machining of Inconel 718 with cutting fluid at conventional pressures. Procedia CIRP. 2018; 77 ():634-637.
Chicago/Turabian StyleVíctor Criado; José Díaz-Álvarez; José Luis Cantero; María Henar Miguélez. 2018. "Study of the performance of PCBN and carbide tools in finishing machining of Inconel 718 with cutting fluid at conventional pressures." Procedia CIRP 77, no. : 634-637.
Inconel 718 is a difficult-to-cut material due to its poor thermal conductivity, severe work hardening and high strength at high temperature. Machining of Inconel 718 with Polycrystalline Cubic Boron Nitride (PCBN) tools at high speed in finishing operations may lead to brittle fracture in the cutting tool because of the low toughness of PCBN inserts in comparison to other cutting materials. PCBN inserts shaped with large tip radius are commonly used to remove small values of depth of cut in order to counteract these aspects. When applying multipass turning strategies with this configuration, a significant peak may occur in the response of the machining forces at the end of the pass in the second and successive passes. This fact may also be present when turning inner profiles or into a shoulder. The increase of the undeformed chip cross section and the high specific cutting forces of Inconel 718 give rise to this peak of the machining forces. In this work, different tests involving multipass finishing turning in Inconel 718 have been carried out in order to study the magnitude of the peak forces for different cutting conditions. A PCBN tool at high cutting speed with coolant has been employed at different feed rates and depths of cut. On the other hand, an analytical study of the undeformed chip section at the end of each turning pass has been performed in order to determine its relation to the machining peak forces. The results have shown that these peaks in the machining forces are strongly related to the tool tip radius and the cutting parameters. The machining force at the end of a turning pass can increase significantly their values during a short interval. Consequently, this effect may influence tool wear progression leading to a premature breakage of the tool.
Diego Infante-Garcia; José Diaz-Álvarez; José-Luis Cantero; Ana Muñoz-Sánchez; Maria-Henar Miguélez. Influence of the undeformed chip cross section in finishing turning of Inconel 718 with PCBN tools. Procedia CIRP 2018, 77, 122 -125.
AMA StyleDiego Infante-Garcia, José Diaz-Álvarez, José-Luis Cantero, Ana Muñoz-Sánchez, Maria-Henar Miguélez. Influence of the undeformed chip cross section in finishing turning of Inconel 718 with PCBN tools. Procedia CIRP. 2018; 77 ():122-125.
Chicago/Turabian StyleDiego Infante-Garcia; José Diaz-Álvarez; José-Luis Cantero; Ana Muñoz-Sánchez; Maria-Henar Miguélez. 2018. "Influence of the undeformed chip cross section in finishing turning of Inconel 718 with PCBN tools." Procedia CIRP 77, no. : 122-125.
In this work, two educational resources for self-learning of Descriptive Geometry are presented: the “Zero Course” and the “Support Course”. The creation of this e-learning material responds to the need that our students at University Carlos III de Madrid have to reach a minimum level at the beginning (Zero Course), and during (Support Course) the first course on technical drawing. First, the need is made out through results of surveys carried out in previous years. Then, some e-learning applications are exposed, among which the most appropriate to the need are chosen. Finally, the designed courses are described including all the technical resources. The results of the surveys carried out on the students of these courses, as well as some statistics of their qualifications, are also presented.
C. Álvarez-Caldas; J. Meneses; S. Santos; A. M. Gómez; A. Díaz; J. A. Calvo; A. Muñoz. Educational Resources for Self-learning of Descriptive Geometry. Mechanical Engineering and Materials 2018, 186 -194.
AMA StyleC. Álvarez-Caldas, J. Meneses, S. Santos, A. M. Gómez, A. Díaz, J. A. Calvo, A. Muñoz. Educational Resources for Self-learning of Descriptive Geometry. Mechanical Engineering and Materials. 2018; ():186-194.
Chicago/Turabian StyleC. Álvarez-Caldas; J. Meneses; S. Santos; A. M. Gómez; A. Díaz; J. A. Calvo; A. Muñoz. 2018. "Educational Resources for Self-learning of Descriptive Geometry." Mechanical Engineering and Materials , no. : 186-194.
Inconel 718 is a Ni superalloy widely used in high responsibility components requiring excellent mechanical properties at high temperature and elevated corrosion resistance. Inconel 718 is a difficult to cut material due to the elevated temperature generated during cutting, its low thermal conductivity, and the strong abrasive tool wear during cutting process. Finishing operations should ensure surface integrity of the component commonly requiring the use of hard metal tools with sharp tool edges and moderate cutting speeds. Polycrystalline cubic boron nitride (PCBN) tools recently developed an enhanced toughness suitable for these final operations. This paper focuses on the study of PCBN tools performance in finishing turning of Inconel 718. Several inserts representative of different manufacturers were tested and compared to a reference carbide tool. The evolution of tool wear, surface roughness, and cutting forces was analyzed and discussed. PCBN tools demonstrated their suitability for finishing operations, presenting reasonable removal rates and surface quality.
José Díaz-Álvarez; Víctor Criado; Henar Miguélez; José Luis Cantero. PCBN Performance in High Speed Finishing Turning of Inconel 718. Metals 2018, 8, 582 .
AMA StyleJosé Díaz-Álvarez, Víctor Criado, Henar Miguélez, José Luis Cantero. PCBN Performance in High Speed Finishing Turning of Inconel 718. Metals. 2018; 8 (8):582.
Chicago/Turabian StyleJosé Díaz-Álvarez; Víctor Criado; Henar Miguélez; José Luis Cantero. 2018. "PCBN Performance in High Speed Finishing Turning of Inconel 718." Metals 8, no. 8: 582.
Inconel 718 is a superalloy, considered one of the least machinable materials. Tools must withstand a high level of temperatures and pressures in a very localized area, the abrasiveness of the hard carbides contained in the Inconel 718 microstructure and the adhesion tendency during its machining. Mechanical properties along with the low thermal conductivity become an important issue for the tool wear. The finishing operations for Inconel 718 are usually performed after solution heat treatment and age hardening of the material to give the superalloy a higher level of hardness. Carbide tools, cutting fluid (at normal or high pressures) and low cutting speed are the main recommendations for finish turning of Inconel 718. However, dry machining is preferable to the use of cutting fluids, because of its lower environmental impact and cost. Previous research has concluded that the elimination of cutting fluid in these processes is feasible when using hard carbide tools. Recent development of new PCBN (Polycrystalline Cubic Boron Nitride) grades for cutting tools with higher tenacity has allowed the application of these tool grades in the finishing operations of Inconel 718. This work studies the performance of commercial PCBN tools from four different tool manufacturers as well as an additional grade with equivalent performance during finish turning of Inconel 718 under dry conditions. Wear tests were carried out with different cutting conditions, determining the evolution of machining forces, surface roughness and tool wear. It is concluded that it is not industrially viable the high-speed finishing of Inconel 718 in a dry environment.
José Luis Cantero; José Díaz-Álvarez; Diego Infante-Garcia; Marcos Rodríguez; Víctor Criado. High Speed Finish Turning of Inconel 718 Using PCBN Tools under Dry Conditions. Metals 2018, 8, 192 .
AMA StyleJosé Luis Cantero, José Díaz-Álvarez, Diego Infante-Garcia, Marcos Rodríguez, Víctor Criado. High Speed Finish Turning of Inconel 718 Using PCBN Tools under Dry Conditions. Metals. 2018; 8 (3):192.
Chicago/Turabian StyleJosé Luis Cantero; José Díaz-Álvarez; Diego Infante-Garcia; Marcos Rodríguez; Víctor Criado. 2018. "High Speed Finish Turning of Inconel 718 Using PCBN Tools under Dry Conditions." Metals 8, no. 3: 192.
N. Feito; José Díaz Álvarez; J. López-Puente; M.H. Miguelez. Experimental and numerical analysis of step drill bit performance when drilling woven CFRPs. Composite Structures 2018, 184, 1147 -1155.
AMA StyleN. Feito, José Díaz Álvarez, J. López-Puente, M.H. Miguelez. Experimental and numerical analysis of step drill bit performance when drilling woven CFRPs. Composite Structures. 2018; 184 ():1147-1155.
Chicago/Turabian StyleN. Feito; José Díaz Álvarez; J. López-Puente; M.H. Miguelez. 2018. "Experimental and numerical analysis of step drill bit performance when drilling woven CFRPs." Composite Structures 184, no. : 1147-1155.