V. Sklenička, K. Kuchařová, M. Kvapilová, P. Král, J. Dvořák
{"title":"The transition from the power-law to the power-law breakdown regimes in thermal creep of Zr1%Nb cladding alloys","authors":"V. Sklenička, K. Kuchařová, M. Kvapilová, P. Král, J. Dvořák","doi":"10.4149/km_2021_5_279","DOIUrl":"https://doi.org/10.4149/km_2021_5_279","url":null,"abstract":"","PeriodicalId":18519,"journal":{"name":"Metallic Materials","volume":"11 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76892000","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}
The acoustic emission (AE) response of texture-free cast magnesium was studied in-situ during monotonic tension and compression tests at room temperature. The dependence of twinning evolution on loading mode is discussed in detail. Furthermore, it is shown that the contribution of twinning and dislocation slip to AE signal is distinguishable by means of analysis of AE parameters. The findings are corroborated by light optical microscopy and EBSD results, as well. K e y w o r d s: magnesium alloy, acoustic emission, twinning, electron backscattered diffraction
{"title":"Study of twinning in texture-free cast magnesium using acoustic emission technique","authors":"K. Máthis, J. Čapek, P. Harcuba, V. Šíma","doi":"10.4149/km_2013_5_269","DOIUrl":"https://doi.org/10.4149/km_2013_5_269","url":null,"abstract":"The acoustic emission (AE) response of texture-free cast magnesium was studied in-situ during monotonic tension and compression tests at room temperature. The dependence of twinning evolution on loading mode is discussed in detail. Furthermore, it is shown that the contribution of twinning and dislocation slip to AE signal is distinguishable by means of analysis of AE parameters. The findings are corroborated by light optical microscopy and EBSD results, as well. K e y w o r d s: magnesium alloy, acoustic emission, twinning, electron backscattered diffraction","PeriodicalId":18519,"journal":{"name":"Metallic Materials","volume":"5 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76981295","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}
This paper presents the assembly of the miniaturised direct impact compression test method (MDICT) developed at the Institute of Fundamental Technological Research at the Polish Academy of Sciences (IFTR PAS). Additionally, this method was used to investigate the mechanical properties of tantalum at the strain rate of 8× 10 s−1. To analyse the phenomena occurring during the tests, a numerical model of the testing stand was developed and validated. The finite element (FEM) model was expanded to estimate the sources of error achieved in the results using the analytical methods. The effects related to friction, inertia, specimen ratio, adiabatic heating, stress equilibration and strain rate on the stress-strain characteristic observed before and after the analytical correction were discussed. K e y w o r d s: miniaturised Hopkinson bar, tantalum, high strain rates, direct impact, finite element method
{"title":"Application of FEM in the assessment of phenomena associated with dynamic investigations on a miniaturised DICT testing stand","authors":"W. Moćko, Z. Kowalewski","doi":"10.4149/km_2013_1_71","DOIUrl":"https://doi.org/10.4149/km_2013_1_71","url":null,"abstract":"This paper presents the assembly of the miniaturised direct impact compression test method (MDICT) developed at the Institute of Fundamental Technological Research at the Polish Academy of Sciences (IFTR PAS). Additionally, this method was used to investigate the mechanical properties of tantalum at the strain rate of 8× 10 s−1. To analyse the phenomena occurring during the tests, a numerical model of the testing stand was developed and validated. The finite element (FEM) model was expanded to estimate the sources of error achieved in the results using the analytical methods. The effects related to friction, inertia, specimen ratio, adiabatic heating, stress equilibration and strain rate on the stress-strain characteristic observed before and after the analytical correction were discussed. K e y w o r d s: miniaturised Hopkinson bar, tantalum, high strain rates, direct impact, finite element method","PeriodicalId":18519,"journal":{"name":"Metallic Materials","volume":"51 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84689413","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}
V. Homolová, A. Výrostková, L. Čiripová, A. Kroupa
{"title":"Phase analysis of Fe-B-V system","authors":"V. Homolová, A. Výrostková, L. Čiripová, A. Kroupa","doi":"10.4149/km_2013_2_135","DOIUrl":"https://doi.org/10.4149/km_2013_2_135","url":null,"abstract":"","PeriodicalId":18519,"journal":{"name":"Metallic Materials","volume":"10 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85276697","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}
H. Farooq, M. Ahmad, Y. Jamil, A. Hafeez, M. Anwar
Nanosized spinel zinc ferrite was reproducibly synthesized via coprecipitation technique, and effects of variation in digestion temperature on the structural, dielectric and magnetic properties were studied. The crystallite size was found in the range of 4.4–15 nm. X-ray diffraction results revealed that the synthesized materials were of pure normal spinel structure. A very small value of coercivity was observed corresponding to the superparamagnetic behavior of the samples. The dielectric constant measured at 300 K in the frequency range of 600 Hz to 1 MHz showed an exponential decay with increasing frequency. It was observed that the particle size increased with an increase in digestion temperature while saturation magnetization (Ms) decreased. These particles are suitable to be used as Magnetic Resonance Imaging contrast agent. K e y w o r d s: spinel structures, zinc ferrites, coprecipitation, superparamagnetism, dielectric constant
{"title":"Structural, dielectric and magnetic properties of superparamagnetic zinc ferrite nanoparticles synthesized through coprecipitation technique","authors":"H. Farooq, M. Ahmad, Y. Jamil, A. Hafeez, M. Anwar","doi":"10.4149/km_2013_5_305","DOIUrl":"https://doi.org/10.4149/km_2013_5_305","url":null,"abstract":"Nanosized spinel zinc ferrite was reproducibly synthesized via coprecipitation technique, and effects of variation in digestion temperature on the structural, dielectric and magnetic properties were studied. The crystallite size was found in the range of 4.4–15 nm. X-ray diffraction results revealed that the synthesized materials were of pure normal spinel structure. A very small value of coercivity was observed corresponding to the superparamagnetic behavior of the samples. The dielectric constant measured at 300 K in the frequency range of 600 Hz to 1 MHz showed an exponential decay with increasing frequency. It was observed that the particle size increased with an increase in digestion temperature while saturation magnetization (Ms) decreased. These particles are suitable to be used as Magnetic Resonance Imaging contrast agent. K e y w o r d s: spinel structures, zinc ferrites, coprecipitation, superparamagnetism, dielectric constant","PeriodicalId":18519,"journal":{"name":"Metallic Materials","volume":"32 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84217299","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}
The effect of columnar to equiaxed transition (CET) on the microsegregation behaviour of main alloying elements (Ti, Al and Nb) was studied in a peritectic Ti-44Al-5Nb-0.2B-0.2C (at.%) alloy. CET microstructures formed in cylindrical samples prepared by power down technique at a constant cooling rate of 0.5 K s−1 in a Bridgman type apparatus and in a large as-cast ingot were analysed. Microstructural analysis showed that the CET is not sharp but develops gradually during solidification in the studied alloy. A mixed zone composed of columnar and equiaxed grains is formed between the columnar and equiaxed zones. The size of columnar and equiaxed grains depends on the position in the as-cast cast ingot. The severity of the microsegregation expressed by segregation deviation parameters calculated for Nb decreases from columnar to the equiaxed zone in the samples prepared by power down technique as well as in the as-cast ingot. While the calculated segregation deviation parameters for Al and Ti decrease from columnar to equiaxed zone in the samples prepared by power down technique, these parameters show no evolution with the local microstructure in the as-cast ingot. The calculated values of segregation deviation parameters for Al and Ti are significantly lower than those for Nb in all analysed columnar, mixed and equiaxed zones of the samples. K e y w o r d s: titanium aluminides, TiAl, solidification, CET, energy-dispersive spectrometry, microsegregation
在包晶Ti- 44al - 5nb -0.2 b-0.2 c (at.%)合金中，研究了柱状向等轴转变(CET)对主要合金元素(Ti、Al和Nb)显微偏析行为的影响。本文分析了在Bridgman型装置中以0.5 K s−1的恒定冷却速率断电技术制备的圆柱形样品和大型铸态铸锭中形成的CET显微组织。显微组织分析表明，在凝固过程中，锥体不明显，而是逐渐形成的。柱状和等轴晶粒之间形成柱状和等轴晶粒混合带。柱状和等轴晶粒的大小取决于在铸态铸锭中的位置。用偏析偏差参数表示的微偏析程度在降电法制备试样和铸态铸锭中由柱状区向等轴区递减。在降电制备的样品中，Al和Ti的偏析偏差参数从柱状区到等轴区逐渐减小，但在铸态铸锭中，这些参数并没有随着局部组织的变化而变化。在分析样品的柱状区、混合区和等轴区，Al和Ti的偏析偏差参数的计算值均显著低于Nb。主要研究方向:钛铝，TiAl，凝固，CET，能量色散光谱，微偏析
{"title":"Effect of columnar to equiaxed transition on microsegregation behaviour of main alloying elements in peritectic TiAl-based alloy","authors":"J. Lapin, A. Klimová, Z. Gabalcová","doi":"10.4149/km_2013_3_147","DOIUrl":"https://doi.org/10.4149/km_2013_3_147","url":null,"abstract":"The effect of columnar to equiaxed transition (CET) on the microsegregation behaviour of main alloying elements (Ti, Al and Nb) was studied in a peritectic Ti-44Al-5Nb-0.2B-0.2C (at.%) alloy. CET microstructures formed in cylindrical samples prepared by power down technique at a constant cooling rate of 0.5 K s−1 in a Bridgman type apparatus and in a large as-cast ingot were analysed. Microstructural analysis showed that the CET is not sharp but develops gradually during solidification in the studied alloy. A mixed zone composed of columnar and equiaxed grains is formed between the columnar and equiaxed zones. The size of columnar and equiaxed grains depends on the position in the as-cast cast ingot. The severity of the microsegregation expressed by segregation deviation parameters calculated for Nb decreases from columnar to the equiaxed zone in the samples prepared by power down technique as well as in the as-cast ingot. While the calculated segregation deviation parameters for Al and Ti decrease from columnar to equiaxed zone in the samples prepared by power down technique, these parameters show no evolution with the local microstructure in the as-cast ingot. The calculated values of segregation deviation parameters for Al and Ti are significantly lower than those for Nb in all analysed columnar, mixed and equiaxed zones of the samples. K e y w o r d s: titanium aluminides, TiAl, solidification, CET, energy-dispersive spectrometry, microsegregation","PeriodicalId":18519,"journal":{"name":"Metallic Materials","volume":"1743 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86521712","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}
{"title":"An investigation into the effect of welding current on the plasma arc welding of pure titanium","authors":"N. Kahraman, M. Taşkin, B. Gülenç, A. Durgutlu","doi":"10.4149/km_2010_3_179","DOIUrl":"https://doi.org/10.4149/km_2010_3_179","url":null,"abstract":"","PeriodicalId":18519,"journal":{"name":"Metallic Materials","volume":"26 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86101729","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}
E. Balcı, B. Sarikan, M. Übeyli, N. Çamuşcu, R. Yildirim
{"title":"On the ballistic performance of the AA7075 based functionally gradeinforcement","authors":"E. Balcı, B. Sarikan, M. Übeyli, N. Çamuşcu, R. Yildirim","doi":"10.4149/km_2013_4_257","DOIUrl":"https://doi.org/10.4149/km_2013_4_257","url":null,"abstract":"","PeriodicalId":18519,"journal":{"name":"Metallic Materials","volume":"29 3 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80492349","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}
{"title":"Investigation of microstructure and strength of AZ80 magnesium alloy by ECAP and aging treatment","authors":"D. Yin, L. K. Weng, J. Liu, J. Wang","doi":"10.4149/km_2011_1_37","DOIUrl":"https://doi.org/10.4149/km_2011_1_37","url":null,"abstract":"","PeriodicalId":18519,"journal":{"name":"Metallic Materials","volume":"66 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74792865","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}
K. Iždinský, L. Senčeková, F. Simančík, M. Nosko, A. Schoberth
Reactions during infiltration of Mo/Mo silicide wires with Ni and subsequent compaction with HIP were qualitatively assessed in this work. Intense reactions of Ni with Mo/Mo silicide composites were recorded. The extent of these reactions is determined by the amount of available Ni. If excessive Ni is available, Mo and Mo silicides are dissolved with detrimental effect on the composite structure. If less Ni is applied and the intimate contact of Ni with Mo/Mo silicides is shortened substantially, less intense reaction takes place providing the structure with MoSi2 laths crystallized in Ni2Si matrix and ternary MoNiSi appearing as intermediate phase between Mo5Si3 and Ni2Si matrix. HIP moves the system further to equilibrium. Additional diffusion leads to the growth of ternary MoNiSi phase on the cost of Ni2Si binary and Mo silicide phases. HIP improved the structural integrity of the Mo/Mo silicide/Ni composite, however, the oxidation resistance of newly formed phases should be further examined. K e y w o r d s: Mo silicides, infiltration, hot isostatic pressing, structural analysis
{"title":"Structure of Mo/Mo silicide composites infiltrated with molten Ni and subsequently compacted by HIP","authors":"K. Iždinský, L. Senčeková, F. Simančík, M. Nosko, A. Schoberth","doi":"10.4149/km_2013_6_327","DOIUrl":"https://doi.org/10.4149/km_2013_6_327","url":null,"abstract":"Reactions during infiltration of Mo/Mo silicide wires with Ni and subsequent compaction with HIP were qualitatively assessed in this work. Intense reactions of Ni with Mo/Mo silicide composites were recorded. The extent of these reactions is determined by the amount of available Ni. If excessive Ni is available, Mo and Mo silicides are dissolved with detrimental effect on the composite structure. If less Ni is applied and the intimate contact of Ni with Mo/Mo silicides is shortened substantially, less intense reaction takes place providing the structure with MoSi2 laths crystallized in Ni2Si matrix and ternary MoNiSi appearing as intermediate phase between Mo5Si3 and Ni2Si matrix. HIP moves the system further to equilibrium. Additional diffusion leads to the growth of ternary MoNiSi phase on the cost of Ni2Si binary and Mo silicide phases. HIP improved the structural integrity of the Mo/Mo silicide/Ni composite, however, the oxidation resistance of newly formed phases should be further examined. K e y w o r d s: Mo silicides, infiltration, hot isostatic pressing, structural analysis","PeriodicalId":18519,"journal":{"name":"Metallic Materials","volume":"53 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76246077","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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