Pub Date : 2021-05-25DOI: 10.1177/25165984211015482
B. Muralidharan, K. Prabu, G. Rajamurugan
Nickel–Titanium (Ni-Ti) shape memory alloy, commonly called nitinol alloys, finds its primary application in the production of biomedical implants, mainly because of itsrare properties such asshape memory, superelasticity and superior biocompatibility. Laser cutting is anon-traditional machining process for the production ofparts with close tolerances andcomplex geometry. Electrical discharge machining (EDM) of nitinol is associated with more heat-affected zone (HAZ) and recast layer thickness. This article aims to study nitinol’s machining characteristics by alaser source with good beam quality to have a less HAZ, recast layer and striations. Experiments were designed and carried out using central composite designs (CCD) by a pulsed Nd:YAG laser. Analysis based on the different parameters chosen was conducted to determine the parameters; effects, including laser power, frequency and cutting speed concerning the surface roughness. From the results, it is observed that the presence of HAZ is measured up to1. 48 mm from the machined surface. The topography analysis reveals that the striation is identified at high speeds, with less pulse overlapping by columnar micro channels, which can be reduced at high pulse frequency.
{"title":"Pulsed Nd:YAG laser machining of nitinol: An experimental investigation","authors":"B. Muralidharan, K. Prabu, G. Rajamurugan","doi":"10.1177/25165984211015482","DOIUrl":"https://doi.org/10.1177/25165984211015482","url":null,"abstract":"Nickel–Titanium (Ni-Ti) shape memory alloy, commonly called nitinol alloys, finds its primary application in the production of biomedical implants, mainly because of itsrare properties such asshape memory, superelasticity and superior biocompatibility. Laser cutting is anon-traditional machining process for the production ofparts with close tolerances andcomplex geometry. Electrical discharge machining (EDM) of nitinol is associated with more heat-affected zone (HAZ) and recast layer thickness. This article aims to study nitinol’s machining characteristics by alaser source with good beam quality to have a less HAZ, recast layer and striations. Experiments were designed and carried out using central composite designs (CCD) by a pulsed Nd:YAG laser. Analysis based on the different parameters chosen was conducted to determine the parameters; effects, including laser power, frequency and cutting speed concerning the surface roughness. From the results, it is observed that the presence of HAZ is measured up to1. 48 mm from the machined surface. The topography analysis reveals that the striation is identified at high speeds, with less pulse overlapping by columnar micro channels, which can be reduced at high pulse frequency.","PeriodicalId":129806,"journal":{"name":"Journal of Micromanufacturing","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133242972","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-05-25DOI: 10.1177/25165984211015412
A. Mishra, Arvind Kumar
The infrastructure safety and response to the natural or man-caused calamities has always been a top consideration for any modern project. Impact energy absorption is one such area where advanced measures are being adopted to prevent any damage to the infrastructure from any impact caused by vehicles or other elements. Honeycomb structures have been primarily used in such high impact energy absorption applications. With the advent of modern additive manufacturing practices, drastic modifications to the simple honeycombs generally used are possible, thus expanding the reach and capability of these structures. In this article, in-plane uniaxial compression performance of hybrid and hierarchical hexagonal honeycombs has been studied in the context of strain energy absorption for in-plane impact such as the case of vehicle collision to the pillars of flyover or bridges. The polylactic acid (PLA) filament has been used to manufacture the honeycombs through fused deposition modeling (FDM) additive manufacturing technique. Simple hexagonal honeycombs have been studied first at low deformation speed to understand the deformation mechanics under uniaxial compression and its dependence on the unit cell dimensions and cell wall thickness. The effect of transition to the hybrid and hierarchical hexagonal honeycombs on the compression deformation has been highlighted next. While the hierarchical structures show better energy absorption capabilities and plateau stress, the hybrid hexagonal honeycombs show their high loadresistance. Dependence of the mechanical performance of such structures on the unit cell dimensions, orientation and wall thickness has also been examined through detailed experimental analysis.
{"title":"In-plane compression behavior of FDM-manufactured hierarchical and hybrid hierarchical hexagonal honeycombs for infrastructural safety applications","authors":"A. Mishra, Arvind Kumar","doi":"10.1177/25165984211015412","DOIUrl":"https://doi.org/10.1177/25165984211015412","url":null,"abstract":"The infrastructure safety and response to the natural or man-caused calamities has always been a top consideration for any modern project. Impact energy absorption is one such area where advanced measures are being adopted to prevent any damage to the infrastructure from any impact caused by vehicles or other elements. Honeycomb structures have been primarily used in such high impact energy absorption applications. With the advent of modern additive manufacturing practices, drastic modifications to the simple honeycombs generally used are possible, thus expanding the reach and capability of these structures. In this article, in-plane uniaxial compression performance of hybrid and hierarchical hexagonal honeycombs has been studied in the context of strain energy absorption for in-plane impact such as the case of vehicle collision to the pillars of flyover or bridges. The polylactic acid (PLA) filament has been used to manufacture the honeycombs through fused deposition modeling (FDM) additive manufacturing technique. Simple hexagonal honeycombs have been studied first at low deformation speed to understand the deformation mechanics under uniaxial compression and its dependence on the unit cell dimensions and cell wall thickness. The effect of transition to the hybrid and hierarchical hexagonal honeycombs on the compression deformation has been highlighted next. While the hierarchical structures show better energy absorption capabilities and plateau stress, the hybrid hexagonal honeycombs show their high loadresistance. Dependence of the mechanical performance of such structures on the unit cell dimensions, orientation and wall thickness has also been examined through detailed experimental analysis.","PeriodicalId":129806,"journal":{"name":"Journal of Micromanufacturing","volume":"53 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129603904","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-05-25DOI: 10.1177/25165984211015760
P. Mondal, Shweta Saundarkar, N. Khantwal, P. Tiwari, A. Srivastava
The microfluidic devices have attracted considerable attention for their wide range of applications in healthcare, disease diagnosis, and environmental monitoring. We present the fabrication technique, surface wetting, and bonding of a polydimethylsiloxane (PDMS) microfluidic device that will be used as an electroosmotic micromixerfor biomolecules. This technique essentially requires micromold preparation and casting of PDMS. The hardened mold was fabricated on SU-8 using X-ray lithography (XRL) beamline, BL-7, Indus-2 as the synchrotron radiation source at Raja Ramanna Centre for Advanced Technology(RRCAT). The PDMS casting and thermal cross-linking was performed by spin-coating, followed by heating with specific thermocycle. This cross-linked PDMS was bonded with smooth surfaces that were treated with different reactive plasmas using a deep reactive-ion etching (DRIE) system. In a micro fluidic channel, the flow is usually a highly ordered laminar flow and due to lack of turbulence the mixing is very difficult for larger molecules such as peptides, proteins and high-molecular-weight nucleic acids. Here, we propose a microscale mixing device where active mixers are moved by external forces, such as an applied electric field. The dimensions of the fabricated device were generated through computer simulation using the finite-element based COMSOL Multiphysics 5. 4 software. The hydrophobic nature of PDMS hinders the mobility of biomolecules through the microchannel. In this work, plasma-induced surface wettability of PDMS with application of sulfur hexafluoride (SF6) and oxygen (O2) gas recipes was investigated. As a result, the SF6 plasma–treated microchannels became stable hydrophilic and exhibited an increased adhesion or reduced air-bubble trapping during filling with aqueous solutions.
{"title":"Fabrication of microfluidic channel of polydimethylsiloxane using X-ray lithography and its surface nanostructuring","authors":"P. Mondal, Shweta Saundarkar, N. Khantwal, P. Tiwari, A. Srivastava","doi":"10.1177/25165984211015760","DOIUrl":"https://doi.org/10.1177/25165984211015760","url":null,"abstract":"The microfluidic devices have attracted considerable attention for their wide range of applications in healthcare, disease diagnosis, and environmental monitoring. We present the fabrication technique, surface wetting, and bonding of a polydimethylsiloxane (PDMS) microfluidic device that will be used as an electroosmotic micromixerfor biomolecules. This technique essentially requires micromold preparation and casting of PDMS. The hardened mold was fabricated on SU-8 using X-ray lithography (XRL) beamline, BL-7, Indus-2 as the synchrotron radiation source at Raja Ramanna Centre for Advanced Technology(RRCAT). The PDMS casting and thermal cross-linking was performed by spin-coating, followed by heating with specific thermocycle. This cross-linked PDMS was bonded with smooth surfaces that were treated with different reactive plasmas using a deep reactive-ion etching (DRIE) system. In a micro fluidic channel, the flow is usually a highly ordered laminar flow and due to lack of turbulence the mixing is very difficult for larger molecules such as peptides, proteins and high-molecular-weight nucleic acids. Here, we propose a microscale mixing device where active mixers are moved by external forces, such as an applied electric field. The dimensions of the fabricated device were generated through computer simulation using the finite-element based COMSOL Multiphysics 5. 4 software. The hydrophobic nature of PDMS hinders the mobility of biomolecules through the microchannel. In this work, plasma-induced surface wettability of PDMS with application of sulfur hexafluoride (SF6) and oxygen (O2) gas recipes was investigated. As a result, the SF6 plasma–treated microchannels became stable hydrophilic and exhibited an increased adhesion or reduced air-bubble trapping during filling with aqueous solutions.","PeriodicalId":129806,"journal":{"name":"Journal of Micromanufacturing","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132004021","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-05-22DOI: 10.1177/25165984211016281
Emmanuel Paneerselvam, Sree Harsha Choutapalli, H. Kumar, N. Vasa, D. Nakamura, M. Rao, H. Ikenoue, Tiju Thomas
Laser-assisted doping of intrinsic silicon carbide (SiC) films deposited on Si (100) substrates by pulsed laser deposition (PLD) method and its influence on simultaneous annealing of the thin film is studied. PLD grown intrinsic SiC films are transformed to p-type SiC and n-type SiC, using laser-assisted doping in aqueous aluminum chloride and phosphoric solutions, respectively. Simultaneous doping and annealing of the SiC film are observed during laser-assisted doping. By precisely positioning the selectively doped region, lateral p–n diodes are formed on the SiC films without using any mask. Electric characteristics confirmed the formation of a lateral p–n diode structure. Numerical analysis of temperature distribution along the depth of the SiC films explains the mechanism of simultaneous doping and annealing during the laser treatment.
{"title":"Simultaneous laser doping and annealing to form lateral p–n junction diode structure on silicon carbide films","authors":"Emmanuel Paneerselvam, Sree Harsha Choutapalli, H. Kumar, N. Vasa, D. Nakamura, M. Rao, H. Ikenoue, Tiju Thomas","doi":"10.1177/25165984211016281","DOIUrl":"https://doi.org/10.1177/25165984211016281","url":null,"abstract":"Laser-assisted doping of intrinsic silicon carbide (SiC) films deposited on Si (100) substrates by pulsed laser deposition (PLD) method and its influence on simultaneous annealing of the thin film is studied. PLD grown intrinsic SiC films are transformed to p-type SiC and n-type SiC, using laser-assisted doping in aqueous aluminum chloride and phosphoric solutions, respectively. Simultaneous doping and annealing of the SiC film are observed during laser-assisted doping. By precisely positioning the selectively doped region, lateral p–n diodes are formed on the SiC films without using any mask. Electric characteristics confirmed the formation of a lateral p–n diode structure. Numerical analysis of temperature distribution along the depth of the SiC films explains the mechanism of simultaneous doping and annealing during the laser treatment.","PeriodicalId":129806,"journal":{"name":"Journal of Micromanufacturing","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131007777","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-05-20DOI: 10.1177/25165984211015409
S. Prabu, I. Palani
The friction stir welding (FSW) is found to be an effective solid-state process to join Nickel Titanium (NiTi) shape memory alloy. The retention of shape memory effect has enabled the welded NiTi alloy to be exploited in various functional applications. In this article, the NiTi sheets of 1.2 mm thickness are welded using FSW. The tool selection, geometry design and process parameters required to weld NiTi sheets are explored. Interestingly, an attempt is made to actuate the welded NiTi alloy, using laser actuation technique. The laser beam is scanned over the sample at a particular speed, enabling the increase in temperature suitable for physical actuation. A minimum and maximum displacement of 10 mm and 28 mm are recorded for the laser powers of 10 W and 50 W, respectively. Apart from laser actuation, the dynamic mechanical analysis of the welded NiTi alloy is investigated.
{"title":"Investigations on the actuation behaviour of friction stir–welded nickel titanium shape memory alloy using continuous fibre laser","authors":"S. Prabu, I. Palani","doi":"10.1177/25165984211015409","DOIUrl":"https://doi.org/10.1177/25165984211015409","url":null,"abstract":"The friction stir welding (FSW) is found to be an effective solid-state process to join Nickel Titanium (NiTi) shape memory alloy. The retention of shape memory effect has enabled the welded NiTi alloy to be exploited in various functional applications. In this article, the NiTi sheets of 1.2 mm thickness are welded using FSW. The tool selection, geometry design and process parameters required to weld NiTi sheets are explored. Interestingly, an attempt is made to actuate the welded NiTi alloy, using laser actuation technique. The laser beam is scanned over the sample at a particular speed, enabling the increase in temperature suitable for physical actuation. A minimum and maximum displacement of 10 mm and 28 mm are recorded for the laser powers of 10 W and 50 W, respectively. Apart from laser actuation, the dynamic mechanical analysis of the welded NiTi alloy is investigated.","PeriodicalId":129806,"journal":{"name":"Journal of Micromanufacturing","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115472937","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-05-14DOI: 10.1177/25165984211015372
Pradeep Kumar, R. Mittal, R. Singh, S. Joshi
Sapphire is an important ceramic material which finds applications in fields such as temperature sensing, optics, electronics, and ceramic bearings. Polishing of sapphire has always been a difficult task for industries and research communities. Hydrodynamic polishing (HDP) is one of the prominent methods used for polishing of hard and profiled surfaces, whereas rigid tool-based methods such as diamond turning, grinding, and honing have many limitations. The HDP process involves deterministic flow of abrasive particles in the slurry between the workpiece surface and a rotating soft tool to obtain the desired surface finish. A novel experimental setup has been fabricated to realize the conformal hydrodynamic nanopolishing on single crystal sapphire cavity. In this study, the experiments were conducted to understand the effect of abrasive particle size, basicity of slurry, and change in temperature of slurry on the polishing of machined sapphire cavity. The effect of the initial surface roughness of the machined cavity on conformal hydrodynamic nanopolishing has also been investigated. A microcrack/pit-free surface has been found after the final polishing of the sapphire cavity. An improvement of 21% is found in surface finish after the final polishing using abrasive particle size of 0.06 µm. Abrasive slurry with higher basicity (pH 13) does not improve the surface finish. By heating the abrasive slurry to a temperature of 70°C–75°C, surface finish improves by ∼26% as compared to improvement of ∼ 21% at room temperature polishing.
{"title":"Experimental characterization of conformal hydrodynamic nanopolishing of a machined single crystal sapphire cavity","authors":"Pradeep Kumar, R. Mittal, R. Singh, S. Joshi","doi":"10.1177/25165984211015372","DOIUrl":"https://doi.org/10.1177/25165984211015372","url":null,"abstract":"Sapphire is an important ceramic material which finds applications in fields such as temperature sensing, optics, electronics, and ceramic bearings. Polishing of sapphire has always been a difficult task for industries and research communities. Hydrodynamic polishing (HDP) is one of the prominent methods used for polishing of hard and profiled surfaces, whereas rigid tool-based methods such as diamond turning, grinding, and honing have many limitations. The HDP process involves deterministic flow of abrasive particles in the slurry between the workpiece surface and a rotating soft tool to obtain the desired surface finish. A novel experimental setup has been fabricated to realize the conformal hydrodynamic nanopolishing on single crystal sapphire cavity. In this study, the experiments were conducted to understand the effect of abrasive particle size, basicity of slurry, and change in temperature of slurry on the polishing of machined sapphire cavity. The effect of the initial surface roughness of the machined cavity on conformal hydrodynamic nanopolishing has also been investigated. A microcrack/pit-free surface has been found after the final polishing of the sapphire cavity. An improvement of 21% is found in surface finish after the final polishing using abrasive particle size of 0.06 µm. Abrasive slurry with higher basicity (pH 13) does not improve the surface finish. By heating the abrasive slurry to a temperature of 70°C–75°C, surface finish improves by ∼26% as compared to improvement of ∼ 21% at room temperature polishing.","PeriodicalId":129806,"journal":{"name":"Journal of Micromanufacturing","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116137286","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-04-22DOI: 10.1177/25165984211008168
Sooraj Shiby, N. Vasa, Matsuo Shigeki
Pulsed laser-based material removal is a preferred technique for microscribing of copper (Cu) film coated on polymers, as the pulse width limits the heat diffusion. However, experimental studies have shown that microscribing of Cu in air results in recast/redeposit formation and oxidation. Although the water medium can reduce these effects to a certain extent, the material removal rate is lesser for Cu. This article reports the influence of laser pulse duration on a hybrid method to enhance the pulsed laser-assisted microscribing of a copper thin film in the presence of an environmentally friendly sodium chloride salt solution (NaCl). The focused laser beam irradiation of Cu film results in ablation with a temperature of the zone well above the boiling point of Cu, which in turn, can assist in accelerating the chemical reaction. In this hybrid scribing technique, along with laser-based material removal, laser-activated chemical etching also helps in removing the material selectively. A sub-nanosecond laser with a pulse width of 500 ps (picosecond [ps] laser) and a nanosecond laser with a pulse width of 6 ns (nanosecond [ns] laser), with a wavelength of 532 nm, are used to understand the influence of laser pulse duration on this hybrid material removal mechanism. Hybrid microscribing with the ps- and ns lasers in salt solution resulted in an increase in the channel depth by ≈5 µm and ≈9 µm, respectively, compared to the channel depth obtained in deionized water. The theoretical model shows that during the ns laser ablation, the cooling rate is slower, resulting in a high temperature in the ablation zone for a longer duration and improved material removal.
{"title":"Nanosecond and sub-nanosecond laser-assisted microscribing of Cu thin films in a salt solution","authors":"Sooraj Shiby, N. Vasa, Matsuo Shigeki","doi":"10.1177/25165984211008168","DOIUrl":"https://doi.org/10.1177/25165984211008168","url":null,"abstract":"Pulsed laser-based material removal is a preferred technique for microscribing of copper (Cu) film coated on polymers, as the pulse width limits the heat diffusion. However, experimental studies have shown that microscribing of Cu in air results in recast/redeposit formation and oxidation. Although the water medium can reduce these effects to a certain extent, the material removal rate is lesser for Cu. This article reports the influence of laser pulse duration on a hybrid method to enhance the pulsed laser-assisted microscribing of a copper thin film in the presence of an environmentally friendly sodium chloride salt solution (NaCl). The focused laser beam irradiation of Cu film results in ablation with a temperature of the zone well above the boiling point of Cu, which in turn, can assist in accelerating the chemical reaction. In this hybrid scribing technique, along with laser-based material removal, laser-activated chemical etching also helps in removing the material selectively. A sub-nanosecond laser with a pulse width of 500 ps (picosecond [ps] laser) and a nanosecond laser with a pulse width of 6 ns (nanosecond [ns] laser), with a wavelength of 532 nm, are used to understand the influence of laser pulse duration on this hybrid material removal mechanism. Hybrid microscribing with the ps- and ns lasers in salt solution resulted in an increase in the channel depth by ≈5 µm and ≈9 µm, respectively, compared to the channel depth obtained in deionized water. The theoretical model shows that during the ns laser ablation, the cooling rate is slower, resulting in a high temperature in the ablation zone for a longer duration and improved material removal.","PeriodicalId":129806,"journal":{"name":"Journal of Micromanufacturing","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134243020","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-04-20DOI: 10.1177/25165984211008059
Pranesh Dutta, G. Bartarya
In hard turning, the cutting forces are large, which leads to tool wear and tensile nature of residual stresses. Vibration-assisted machining (VAM), where the tool is provided with a low amplitude vibration at significantly high frequency, might improve the process performance of hard turning in terms of cutting forces, residual stress, etc., as VAM helps in reduction of cutting forces and tool wear significantly. To improve the machining operation, a comparative study of VAM with conventional machining is undertaken to study and improve the hard turning performance. A two-dimensional (2D) finite element (FE) model is developed to understand the effect of process parameters better and to study the effect on machining performance by applying one-dimensional ultrasonic vibration to the tool. The model developed is validated with results from a previous work for continuous hard turning conditions. The effect of vibrations induced in cutting velocity direction is studied on the cutting forces and residual stresses induced on the machined workpiece. The ratio of cutting velocity to critical vibrating velocity is an important process parameter that affects the average cutting forces during hard turning using VAM. The nature of cutting force and temperature for a complete cycle of vibration is also studied. The simulation results establish that hard turning using VAM yields lower average cutting forces and more compressive residual stresses in comparison to conventional hard turning.
{"title":"On the improvement of process performance of hard turning using vibration-assisted machining","authors":"Pranesh Dutta, G. Bartarya","doi":"10.1177/25165984211008059","DOIUrl":"https://doi.org/10.1177/25165984211008059","url":null,"abstract":"In hard turning, the cutting forces are large, which leads to tool wear and tensile nature of residual stresses. Vibration-assisted machining (VAM), where the tool is provided with a low amplitude vibration at significantly high frequency, might improve the process performance of hard turning in terms of cutting forces, residual stress, etc., as VAM helps in reduction of cutting forces and tool wear significantly. To improve the machining operation, a comparative study of VAM with conventional machining is undertaken to study and improve the hard turning performance. A two-dimensional (2D) finite element (FE) model is developed to understand the effect of process parameters better and to study the effect on machining performance by applying one-dimensional ultrasonic vibration to the tool. The model developed is validated with results from a previous work for continuous hard turning conditions. The effect of vibrations induced in cutting velocity direction is studied on the cutting forces and residual stresses induced on the machined workpiece. The ratio of cutting velocity to critical vibrating velocity is an important process parameter that affects the average cutting forces during hard turning using VAM. The nature of cutting force and temperature for a complete cycle of vibration is also studied. The simulation results establish that hard turning using VAM yields lower average cutting forces and more compressive residual stresses in comparison to conventional hard turning.","PeriodicalId":129806,"journal":{"name":"Journal of Micromanufacturing","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126641853","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-04-20DOI: 10.1177/25165984211008173
Manjesh Kumar, Hari Narayan Singh Yadav, Abhinav Kumar, M. Das
Surface quality is the most crucial factor affecting the product lifespan and performance of any component. Most earlier technologies display accuracy in the micrometre or submicrometre range, surface roughness in the nanometre range, and almost no surface defects in the production of optical, mechanical and electronic parts. Such finishing methods incorporate a magnetic field to control the finishing forces using magnetorheological fluid as the polishing medium. Magnetorheological fluid (MR) consists of ferromagnetic and abrasive particles. It is a type of modern intelligent fluid. An optimum selection of magnetorheological fluid constituents and their volume concentration plays an essential role for the ultra-fine finishing of newly developed engineering products. Rheological characteristics of magnetorheological fluid can change rapidly and effortlessly with the support of an activated magnetic field. Traditional finishing methods are comparatively inferior in finishing complex freeform surfaces, due to the lack of controlling finishing forces and limitations of polishing tool movement over the complex freeform contour of the components. There are different types of processes based on the magnetorheological fluid including magnetorheological finishing, magnetorheological abrasive flow finishing, rotational magnetorheological abrasive flow finishing and ball end magnetorheological finishing. This article discusses the development of different types of magnetorheological-fluid-based finishing processes and their modes of operation. The MR fluid devices developed in the last decade are thoroughly reviewed for their working principles, characteristics and applications. This article also highlights the study of rheological characterization of magnetorheological fluid and its applications in different polishing methods appropriate for finishing various complex freeform components.
{"title":"An overview of magnetorheological polishing fluid applied in nano-finishing of components","authors":"Manjesh Kumar, Hari Narayan Singh Yadav, Abhinav Kumar, M. Das","doi":"10.1177/25165984211008173","DOIUrl":"https://doi.org/10.1177/25165984211008173","url":null,"abstract":"Surface quality is the most crucial factor affecting the product lifespan and performance of any component. Most earlier technologies display accuracy in the micrometre or submicrometre range, surface roughness in the nanometre range, and almost no surface defects in the production of optical, mechanical and electronic parts. Such finishing methods incorporate a magnetic field to control the finishing forces using magnetorheological fluid as the polishing medium. Magnetorheological fluid (MR) consists of ferromagnetic and abrasive particles. It is a type of modern intelligent fluid. An optimum selection of magnetorheological fluid constituents and their volume concentration plays an essential role for the ultra-fine finishing of newly developed engineering products. Rheological characteristics of magnetorheological fluid can change rapidly and effortlessly with the support of an activated magnetic field. Traditional finishing methods are comparatively inferior in finishing complex freeform surfaces, due to the lack of controlling finishing forces and limitations of polishing tool movement over the complex freeform contour of the components. There are different types of processes based on the magnetorheological fluid including magnetorheological finishing, magnetorheological abrasive flow finishing, rotational magnetorheological abrasive flow finishing and ball end magnetorheological finishing. This article discusses the development of different types of magnetorheological-fluid-based finishing processes and their modes of operation. The MR fluid devices developed in the last decade are thoroughly reviewed for their working principles, characteristics and applications. This article also highlights the study of rheological characterization of magnetorheological fluid and its applications in different polishing methods appropriate for finishing various complex freeform components.","PeriodicalId":129806,"journal":{"name":"Journal of Micromanufacturing","volume":"411 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121816956","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-26DOI: 10.1177/2516598420984362
A. Sen, B. Doloi, B. Bhattacharyya
The present article deals with the generation of micro-grooves on 316L stainless steel (SS) by a nanosecond pulsed fiber laser system. Fabrication of micro-grooves on 316L SS has immensely contributed to the biomedical and automotive industries through improving the mechanical, lubrication, and corrosion resistance properties. In the present work, the considered process parameters are the preheating temperature (100°C and 200°C), along with the room temperature (24°C), cutting speed, sawing angle, pulse frequency, and laser power. The ranges of cutting speed and sawing angle are 0.1–1.1 mm s−1 and 0.1°–1°, respectively. Besides, pulse frequency and laser power vary from 55 kHz to 85 kHz and from 15 W to 45 W, respectively. The constant parameters are the pulse width of 99% and assist air pressure of 6 kgf cm−2. The variable parameters for the analysis are cut width and heat-affected zone (HAZ) width. The article aims to showcase a comprehensive study of fiber laser process parameters at different temperatures (preheated condition and room temperature) with variable sawing angles to produce better process control and bring about each considered process parameter’s critical value. The experimental results show that higher dimensions of cut width and HAZ width are observed at 200°C with the increment of sawing angle and laser power, compared to other temperatures. With the increment of cutting speed and laser power, the HAZ width tends to rise sharply. A significant drop in cut width and HAZ width dimensions is observed with the increment in pulse frequency for any temperature.
本文研究了用纳秒脉冲光纤激光系统在316L不锈钢(SS)上产生微凹槽。在316L SS上制造微凹槽通过改善机械，润滑和耐腐蚀性，为生物医学和汽车工业做出了巨大贡献。在本工作中，考虑的工艺参数为预热温度(100°C和200°C)，以及室温(24°C)，切割速度，锯切角度，脉冲频率和激光功率。切割速度范围为0.1 ~ 1.1 mm s−1，锯切角度范围为0.1°~ 1°。脉冲频率为55 kHz ~ 85 kHz，激光功率为15 W ~ 45 W。恒定参数为脉冲宽度为99%，辅助气压为6 kgf cm−2。用于分析的可变参数是切割宽度和热影响区宽度。本文旨在全面研究不同温度(预热状态和室温)、不同锯切角度下的光纤激光工艺参数，以便更好地进行工艺控制，并得出所考虑的各个工艺参数的临界值。实验结果表明，与其他温度相比，在200°C时，随着锯切角度和激光功率的增加，切割宽度和热影响区宽度的尺寸增大。随着切割速度和激光功率的增加，热影响区宽度有急剧上升的趋势。在任何温度下，随着脉冲频率的增加，切割宽度和热影响区宽度尺寸显著下降。
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