{"title":"深度过冷镍和铜熔体中枝晶尖端扰动状态的参数","authors":"O. Shablovsky, D. Kroll","doi":"10.52928/2070-1624-2024-42-1-60-68","DOIUrl":null,"url":null,"abstract":"The object of study is the morphological stability of the tip of a free dendrite in a supercooled melt of a pure \nsubstance. Areas of deep supercooling are considered: for nickel DT > 166 K, for copper – DT > 180 K. A distinctive \nfeature of the processes being studied is the presence of two propagation velocities of small disturbances \n(velocities of “sound”). The dependences of these rates on the supercooling of the melt were determined. The periodic \nand coordinate-aperiodic modes of perturbation of the growth line have been studied in detail. For these stable \nregimes, the possibility of observing the same speed of the disturbance wave in two processes, differing from each \nother in the size of the spatial inhomogeneity of the background in front of the wave and the characteristic wave \nattenuation times, was discovered. It is shown that aperiodic instability appears if, after the passage of the wave \nfront, the width of the growth line inhomogeneity zone decreases. The resonant excitation mode of the dendrite tip \ndemonstrates important differences between the properties of the nickel and copper melts. First of all, this relates \nto the temperature dependences of the resonant frequency and the speed of a standing wave formed in the vicinity \nof the vertex. Numerical calculations are presented and graphic information is presented illustrating the patterns \nof growth of nickel and copper dendrites.","PeriodicalId":386243,"journal":{"name":"HERALD OF POLOTSK STATE UNIVERSITY. Series С FUNDAMENTAL SCIENCES","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"2024-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"PARAMETERS OF THE PERTURBED STATE OF THE DENDRITE TIP \\nIN DEEPLY SUPERCOOLED NICKEL AND COPPER MELTS\",\"authors\":\"O. Shablovsky, D. Kroll\",\"doi\":\"10.52928/2070-1624-2024-42-1-60-68\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"The object of study is the morphological stability of the tip of a free dendrite in a supercooled melt of a pure \\nsubstance. Areas of deep supercooling are considered: for nickel DT > 166 K, for copper – DT > 180 K. A distinctive \\nfeature of the processes being studied is the presence of two propagation velocities of small disturbances \\n(velocities of “sound”). The dependences of these rates on the supercooling of the melt were determined. The periodic \\nand coordinate-aperiodic modes of perturbation of the growth line have been studied in detail. For these stable \\nregimes, the possibility of observing the same speed of the disturbance wave in two processes, differing from each \\nother in the size of the spatial inhomogeneity of the background in front of the wave and the characteristic wave \\nattenuation times, was discovered. It is shown that aperiodic instability appears if, after the passage of the wave \\nfront, the width of the growth line inhomogeneity zone decreases. The resonant excitation mode of the dendrite tip \\ndemonstrates important differences between the properties of the nickel and copper melts. First of all, this relates \\nto the temperature dependences of the resonant frequency and the speed of a standing wave formed in the vicinity \\nof the vertex. Numerical calculations are presented and graphic information is presented illustrating the patterns \\nof growth of nickel and copper dendrites.\",\"PeriodicalId\":386243,\"journal\":{\"name\":\"HERALD OF POLOTSK STATE UNIVERSITY. Series С FUNDAMENTAL SCIENCES\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2024-04-24\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"HERALD OF POLOTSK STATE UNIVERSITY. Series С FUNDAMENTAL SCIENCES\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/10.52928/2070-1624-2024-42-1-60-68\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"HERALD OF POLOTSK STATE UNIVERSITY. Series С FUNDAMENTAL SCIENCES","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.52928/2070-1624-2024-42-1-60-68","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
PARAMETERS OF THE PERTURBED STATE OF THE DENDRITE TIP
IN DEEPLY SUPERCOOLED NICKEL AND COPPER MELTS
The object of study is the morphological stability of the tip of a free dendrite in a supercooled melt of a pure
substance. Areas of deep supercooling are considered: for nickel DT > 166 K, for copper – DT > 180 K. A distinctive
feature of the processes being studied is the presence of two propagation velocities of small disturbances
(velocities of “sound”). The dependences of these rates on the supercooling of the melt were determined. The periodic
and coordinate-aperiodic modes of perturbation of the growth line have been studied in detail. For these stable
regimes, the possibility of observing the same speed of the disturbance wave in two processes, differing from each
other in the size of the spatial inhomogeneity of the background in front of the wave and the characteristic wave
attenuation times, was discovered. It is shown that aperiodic instability appears if, after the passage of the wave
front, the width of the growth line inhomogeneity zone decreases. The resonant excitation mode of the dendrite tip
demonstrates important differences between the properties of the nickel and copper melts. First of all, this relates
to the temperature dependences of the resonant frequency and the speed of a standing wave formed in the vicinity
of the vertex. Numerical calculations are presented and graphic information is presented illustrating the patterns
of growth of nickel and copper dendrites.