E. Stoian, V. Bratu, R. Bratu, I. Petre, M. Enescu, C. Rusănescu
Abstract An important category of widely used steels is chromium alloy improvement steels (STAS 9382/4-89) intended for the execution of shafts, axles, cams, sprockets and sprockets subjected to operation at important demands. The properties of these steels are determined both by the chemical composition and by the way of plastic elaboration and deformation, but also by the way in which the structural transformations to the thermal treatments of tempering and recovery result. The properties of a certain steel are largely determined by the granulation size of the secondary structure, which in turn is dependent on the size of the austenitic granulation, respectively the hereditary granulation. At a given steel mark, the mode of heating (slow or fast) at the austenitization temperature is decisive regarding the dimensions of the austenitic grain respectively of the nature of the secondary granulation and of the operating properties. Studies and research were conducted on steels with an average content of 0.5% C (OLC 50, 40Cr10, 40Cr30), respectively alloys and chromium alloys. The experimental results show that the number of germs increases with the increase of the heating rate at austenitization. Along with the influence it has on the number of germs, the speed of heating manifests its effects on the critical temperatures of transformation. The presence of chromium additions is manifested by phenomena of carbide stabilization.
{"title":"Studies and Researches on Heating Microstructures of Some Steels","authors":"E. Stoian, V. Bratu, R. Bratu, I. Petre, M. Enescu, C. Rusănescu","doi":"10.2478/bsmm-2022-0001","DOIUrl":"https://doi.org/10.2478/bsmm-2022-0001","url":null,"abstract":"Abstract An important category of widely used steels is chromium alloy improvement steels (STAS 9382/4-89) intended for the execution of shafts, axles, cams, sprockets and sprockets subjected to operation at important demands. The properties of these steels are determined both by the chemical composition and by the way of plastic elaboration and deformation, but also by the way in which the structural transformations to the thermal treatments of tempering and recovery result. The properties of a certain steel are largely determined by the granulation size of the secondary structure, which in turn is dependent on the size of the austenitic granulation, respectively the hereditary granulation. At a given steel mark, the mode of heating (slow or fast) at the austenitization temperature is decisive regarding the dimensions of the austenitic grain respectively of the nature of the secondary granulation and of the operating properties. Studies and research were conducted on steels with an average content of 0.5% C (OLC 50, 40Cr10, 40Cr30), respectively alloys and chromium alloys. The experimental results show that the number of germs increases with the increase of the heating rate at austenitization. Along with the influence it has on the number of germs, the speed of heating manifests its effects on the critical temperatures of transformation. The presence of chromium additions is manifested by phenomena of carbide stabilization.","PeriodicalId":30754,"journal":{"name":"Scientific Bulletin of Valahia University Materials and Mechanics","volume":"28 1","pages":"7 - 11"},"PeriodicalIF":0.0,"publicationDate":"2022-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82867329","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}
F. Anghelina, I. Popescu, C. Popa, D. Ungureanu, I. Popa
Abstract Diffraction techniques and methods with X-rays and less diffraction of electrons, neutrons, etc. are frequently used to investigate the fine structure. X-ray techniques have the advantage that they are cheaper and provide statistical information at the level of fine ordered structure and are not significantly disturbed by the magnetic state of the substance. But the experimental reality complicates matters. The geometric divergence (vertical and horizontal) of the incident beam, the deviation from the ideal monochromatism and the diffraction geometry induce certain corrections for the expression of the integral diffraction intensity. This article addresses the calculation of the integral diffraction intensity affected by these factors for certain methods of X-ray structural analysis.
{"title":"Correction of the Expression of the Integral Diffraction Intensity for Certain Types of X-Ray Structural Analysis Methods","authors":"F. Anghelina, I. Popescu, C. Popa, D. Ungureanu, I. Popa","doi":"10.2478/bsmm-2022-0003","DOIUrl":"https://doi.org/10.2478/bsmm-2022-0003","url":null,"abstract":"Abstract Diffraction techniques and methods with X-rays and less diffraction of electrons, neutrons, etc. are frequently used to investigate the fine structure. X-ray techniques have the advantage that they are cheaper and provide statistical information at the level of fine ordered structure and are not significantly disturbed by the magnetic state of the substance. But the experimental reality complicates matters. The geometric divergence (vertical and horizontal) of the incident beam, the deviation from the ideal monochromatism and the diffraction geometry induce certain corrections for the expression of the integral diffraction intensity. This article addresses the calculation of the integral diffraction intensity affected by these factors for certain methods of X-ray structural analysis.","PeriodicalId":30754,"journal":{"name":"Scientific Bulletin of Valahia University Materials and Mechanics","volume":"48 1","pages":"21 - 25"},"PeriodicalIF":0.0,"publicationDate":"2022-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73529801","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}
Abstract The use of guide ways in apparatus, devices and machines construction is frequent that the aspects concerning their accuracy and durability are elements defining technical performances. The paper proposes a mathematical model for calculating the wear of torques with sliding motion. The proposed model makes it possible to establish a link between wear and tear and the accuracy of the movement of the moving part during operation. The model can be applied in the design phase for a known geometry and operating conditions.
{"title":"Mathematical Modeling of Wear of Plane Translation Couples","authors":"I. Petre, M. Enescu, E. Stoian","doi":"10.2478/bsmm-2022-0006","DOIUrl":"https://doi.org/10.2478/bsmm-2022-0006","url":null,"abstract":"Abstract The use of guide ways in apparatus, devices and machines construction is frequent that the aspects concerning their accuracy and durability are elements defining technical performances. The paper proposes a mathematical model for calculating the wear of torques with sliding motion. The proposed model makes it possible to establish a link between wear and tear and the accuracy of the movement of the moving part during operation. The model can be applied in the design phase for a known geometry and operating conditions.","PeriodicalId":30754,"journal":{"name":"Scientific Bulletin of Valahia University Materials and Mechanics","volume":"72 1","pages":"38 - 41"},"PeriodicalIF":0.0,"publicationDate":"2022-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86260636","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}
M. Ardeleanu, Iulian Ilie, Emil Mihail Diaconu, A. Gheorghe
Abstract The possibility to work by using small objects, under the microscopic view, it is a challenge. The force’s spectrum differs from that of the macroscopic scale, and many unexpected force vectors will appear. A sharp tip must be the ideal pressure vector on different microscopic small object to push, roll, and brake and so on. The positioning of this tip must be a very precise one, comparatively with the working area dimensions and we consider that 10 microns can be a reasonable measuring unit for these moves that are executed into a specific way in these kinds of cases. The mechatronic system designed to actuate the tip, becomes this paper subject. Indisputable we will talk about an actuator with one or more than one freedom degrees. Mechanical aspects are secondary, but necessary to understand the impact of electrical parameters on the minimum possible unit of movement. Electronic control refers to a switching and PWM signal, through a software that develops both the effective part of generating the control signal and the HMI interface through a touch-screen. The aim of this paper was to determine the minimum micrometric travel distance that can be obtained with a 12-bit PWM signal generated by a Raspberry mini-computer
{"title":"Mechatronic System Integrating an Electromagnetic Actuator with the Possibility of Moving the Working Microscopic Tool at Submicrometric Resolutions","authors":"M. Ardeleanu, Iulian Ilie, Emil Mihail Diaconu, A. Gheorghe","doi":"10.2478/bsmm-2022-0007","DOIUrl":"https://doi.org/10.2478/bsmm-2022-0007","url":null,"abstract":"Abstract The possibility to work by using small objects, under the microscopic view, it is a challenge. The force’s spectrum differs from that of the macroscopic scale, and many unexpected force vectors will appear. A sharp tip must be the ideal pressure vector on different microscopic small object to push, roll, and brake and so on. The positioning of this tip must be a very precise one, comparatively with the working area dimensions and we consider that 10 microns can be a reasonable measuring unit for these moves that are executed into a specific way in these kinds of cases. The mechatronic system designed to actuate the tip, becomes this paper subject. Indisputable we will talk about an actuator with one or more than one freedom degrees. Mechanical aspects are secondary, but necessary to understand the impact of electrical parameters on the minimum possible unit of movement. Electronic control refers to a switching and PWM signal, through a software that develops both the effective part of generating the control signal and the HMI interface through a touch-screen. The aim of this paper was to determine the minimum micrometric travel distance that can be obtained with a 12-bit PWM signal generated by a Raspberry mini-computer","PeriodicalId":30754,"journal":{"name":"Scientific Bulletin of Valahia University Materials and Mechanics","volume":"85 1","pages":"42 - 44"},"PeriodicalIF":0.0,"publicationDate":"2022-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89593805","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Catangiu, I. Popescu, D. Ungureanu, A. Poinescu
Abstract The aim of this paper is to present a handmade laboratory device with data acquisition for estimating the thermomechanical characteristics (caused by dimensional changes in height) of polymeric materials. This experimental device is able to perform penetration tests, monitoring the expansion of the samples and based on experimental tests, the thermal expansivity or coefficient of thermal expansion (CTE) can be determined. A data acquisition instrument, which register (i) the deformation of the specimen, by using two displacement transducers (an inductive proximity transducer and an transmission type photoelectric linear encoder) as well as registers (ii) the temperature (at the base of the specimen and in the vicinity of the point of contact with the penetrator) is used. In order to test the device and to highlight its qualities, preliminary tests were carried out on a thermosetting polymeric material in various stages of polymerization.
{"title":"Development of Experimental Device with Data Acquisition for Thermomechanical Characterization of Polymers","authors":"A. Catangiu, I. Popescu, D. Ungureanu, A. Poinescu","doi":"10.2478/bsmm-2022-0004","DOIUrl":"https://doi.org/10.2478/bsmm-2022-0004","url":null,"abstract":"Abstract The aim of this paper is to present a handmade laboratory device with data acquisition for estimating the thermomechanical characteristics (caused by dimensional changes in height) of polymeric materials. This experimental device is able to perform penetration tests, monitoring the expansion of the samples and based on experimental tests, the thermal expansivity or coefficient of thermal expansion (CTE) can be determined. A data acquisition instrument, which register (i) the deformation of the specimen, by using two displacement transducers (an inductive proximity transducer and an transmission type photoelectric linear encoder) as well as registers (ii) the temperature (at the base of the specimen and in the vicinity of the point of contact with the penetrator) is used. In order to test the device and to highlight its qualities, preliminary tests were carried out on a thermosetting polymeric material in various stages of polymerization.","PeriodicalId":30754,"journal":{"name":"Scientific Bulletin of Valahia University Materials and Mechanics","volume":"12 1","pages":"26 - 32"},"PeriodicalIF":0.0,"publicationDate":"2022-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84781524","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}
Abstract In this part of the paper, we will study the behavior of PUR polyurethane at different mechanical and thermal stresses, stresses for which this material behaves very well. It is known that this material behaves well as a protective material against shocks, so it is used as protection against mechanical elements. PUR behaves excellently at uneven static stresses and dynamic stresses. That is why it is used in the construction of the rollers of medium weight mobile devices or rollers that have cam functionality, strongly required for static and dynamic contact. PUR has very good thermal properties, it is used as a thermal insulator when it is in the form of high-density polyurethane foam (PUR / PIR).
{"title":"Virtual Studies on the Behavior of Polyurethane on Mechanical Stresses","authors":"A. Negrea, M. Enescu, E. Stoian, I. Petre","doi":"10.2478/bsmm-2022-0008","DOIUrl":"https://doi.org/10.2478/bsmm-2022-0008","url":null,"abstract":"Abstract In this part of the paper, we will study the behavior of PUR polyurethane at different mechanical and thermal stresses, stresses for which this material behaves very well. It is known that this material behaves well as a protective material against shocks, so it is used as protection against mechanical elements. PUR behaves excellently at uneven static stresses and dynamic stresses. That is why it is used in the construction of the rollers of medium weight mobile devices or rollers that have cam functionality, strongly required for static and dynamic contact. PUR has very good thermal properties, it is used as a thermal insulator when it is in the form of high-density polyurethane foam (PUR / PIR).","PeriodicalId":30754,"journal":{"name":"Scientific Bulletin of Valahia University Materials and Mechanics","volume":"3 1","pages":"45 - 52"},"PeriodicalIF":0.0,"publicationDate":"2022-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78996768","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}
Abstract The cultural heritage field represents a witness to artifacts values in a continuous evolution, it strongly influences our sense of identity and our behavior as people. To protect these archaeological treasures, different conservation and restoration methods are required. Considering the field of priceless artifacts, our research direction led us to preliminary studies of metallic coins from 20th century through non–destructive techniques. Copper–based coins were subjected to the surface characterization through optical microscopy (OM) in transmitted light, elemental composition analysis using Wavelength Dispersive X-ray Fluorescence (WDXRF) and electrochemical corrosion using Tafel extrapolarization technique. The microscopic investigations showed that the patina layer is due to presence of copper content in coins composition confirmed by X-ray fluorescence spectroscopy technique. Also, the electrochemical tests disclosed different corrosion rate according to each chemical composition of coins. This study provide a broad overview of ancient coins to preserve their value in the future.
{"title":"Surface, Elemental and Electrochemical Characterizations of Ancient Coins By Non – Destructive Techniques","authors":"R. Ion, M. David, A. Gheboianu","doi":"10.2478/bsmm-2022-0002","DOIUrl":"https://doi.org/10.2478/bsmm-2022-0002","url":null,"abstract":"Abstract The cultural heritage field represents a witness to artifacts values in a continuous evolution, it strongly influences our sense of identity and our behavior as people. To protect these archaeological treasures, different conservation and restoration methods are required. Considering the field of priceless artifacts, our research direction led us to preliminary studies of metallic coins from 20th century through non–destructive techniques. Copper–based coins were subjected to the surface characterization through optical microscopy (OM) in transmitted light, elemental composition analysis using Wavelength Dispersive X-ray Fluorescence (WDXRF) and electrochemical corrosion using Tafel extrapolarization technique. The microscopic investigations showed that the patina layer is due to presence of copper content in coins composition confirmed by X-ray fluorescence spectroscopy technique. Also, the electrochemical tests disclosed different corrosion rate according to each chemical composition of coins. This study provide a broad overview of ancient coins to preserve their value in the future.","PeriodicalId":30754,"journal":{"name":"Scientific Bulletin of Valahia University Materials and Mechanics","volume":"54 1","pages":"12 - 20"},"PeriodicalIF":0.0,"publicationDate":"2022-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80059245","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}
Abstract The present work aims to study the adsorption processes and the photochemical depollution of the waters contaminated with Direct Orange textile dyes - 26 released into the water. Also, the paper shows the polysulfone (PSf) membranes, used for adsorption processes of the textile dyes azo - direct-orange-26, presenting the kinetics and experimental adsorption conditions for such processes. Advanced oxidation processes (AOP) processes used in photochemical depollution technologies are studied for water contaminated with Direct Orange 26 textile dye, after a preliminary adsorption process, with ZnFe2O4 ferrite photocatalysts.
{"title":"Adsorption Processes Coupled with Photochemical Depolution of Waters Contaminated with Direct Orange-26 Azo Dye","authors":"R. Ion, L. Iancu, R. Grigorescu, M. David","doi":"10.2478/bsmm-2022-0005","DOIUrl":"https://doi.org/10.2478/bsmm-2022-0005","url":null,"abstract":"Abstract The present work aims to study the adsorption processes and the photochemical depollution of the waters contaminated with Direct Orange textile dyes - 26 released into the water. Also, the paper shows the polysulfone (PSf) membranes, used for adsorption processes of the textile dyes azo - direct-orange-26, presenting the kinetics and experimental adsorption conditions for such processes. Advanced oxidation processes (AOP) processes used in photochemical depollution technologies are studied for water contaminated with Direct Orange 26 textile dye, after a preliminary adsorption process, with ZnFe2O4 ferrite photocatalysts.","PeriodicalId":30754,"journal":{"name":"Scientific Bulletin of Valahia University Materials and Mechanics","volume":"6 1","pages":"33 - 37"},"PeriodicalIF":0.0,"publicationDate":"2022-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80160221","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}
Abstract This scientific paper presents the progressive conceptions of the future from Mechatronics to Cyber-Mechatronics and from Mechatronics Systems to Cyber-Mechatronics Systems, highlighting the scientific and technological advances in the mentioned fields, the new and complex innovative concepts of science and Mechatronics and Cyber-Mechatronics engineering and the constructive and applied architectures of the Mechatronics and Cyber-Mechatronics Systems, which will develop and merge the Physical World (Mechatronics) with the virtual world.
{"title":"Progressive Conceptions of the Future in Cyber-Mix Mechatronics Industry and Claytronics Engineering (I)","authors":"G. Gheorghe, V. Despa","doi":"10.2478/bsmm-2022-0009","DOIUrl":"https://doi.org/10.2478/bsmm-2022-0009","url":null,"abstract":"Abstract This scientific paper presents the progressive conceptions of the future from Mechatronics to Cyber-Mechatronics and from Mechatronics Systems to Cyber-Mechatronics Systems, highlighting the scientific and technological advances in the mentioned fields, the new and complex innovative concepts of science and Mechatronics and Cyber-Mechatronics engineering and the constructive and applied architectures of the Mechatronics and Cyber-Mechatronics Systems, which will develop and merge the Physical World (Mechatronics) with the virtual world.","PeriodicalId":30754,"journal":{"name":"Scientific Bulletin of Valahia University Materials and Mechanics","volume":"27 1","pages":"53 - 57"},"PeriodicalIF":0.0,"publicationDate":"2022-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84854498","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}
Abstract The present study refers to a plane circular plate, provided with equidistant radial ribs, placed on one side (fig. 1), these having the same geometry of the cross section (thickness and height) along their entire length (fig.2). There is a change in the position of the neutral fiber of the ribbed plate and also in its bending rigidity, along the radius of the plate, in different cases.
{"title":"Rigidity of Circular Plates with Radial Ribs, Placed on One Side, Neglecting the Influence of Welding Seams. Nerves with Constant Thickness and Height Along the Entire Length","authors":"C. Popa, V. Anghelina, V. Despa","doi":"10.2478/bsmm-2022-0010","DOIUrl":"https://doi.org/10.2478/bsmm-2022-0010","url":null,"abstract":"Abstract The present study refers to a plane circular plate, provided with equidistant radial ribs, placed on one side (fig. 1), these having the same geometry of the cross section (thickness and height) along their entire length (fig.2). There is a change in the position of the neutral fiber of the ribbed plate and also in its bending rigidity, along the radius of the plate, in different cases.","PeriodicalId":30754,"journal":{"name":"Scientific Bulletin of Valahia University Materials and Mechanics","volume":"31 1","pages":"58 - 62"},"PeriodicalIF":0.0,"publicationDate":"2022-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84018881","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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