Abstract: Daqu distiller's grains were co-fermented as raw materials by Trichoderma.koningii and Trichosporon cutaneum to produce microbial oils, which can provide raw materials for bio-diesel development. The singl...Abstract: Daqu distiller's grains were co-fermented as raw materials by Trichoderma.koningii and Trichosporon cutaneum to produce microbial oils, which can provide raw materials for bio-diesel development. The single factor tests were used to investigate the effects of ratio of strains, inoculum size, culture temperature and culture time on the production of microbial oils. The best processing conditions were obtained by orthogonal test through measuring the content of microbial oils in product. The result shows that the microbial oils content of the co-fermented product under the ratio of Trichoderma.koningii to Trichosporon cutaneum of 1:1, the inoculum size of strains of 11% at 28 ℃ for 6 d is 7.15 g/L. It is shown that the production of microbial oils co-fermented by Trichoderma.koningii and Trichosporon cutaneum with Daqu distiller's grains is possible. The research provides a new idea for the reuse of Daqu distiller's grains and also provides a new way for the development of microbial oils.展开更多
Cereal grains can contribute to maintain health and prevent chronic diseases by supplying biologically active components. The exact mechanism of action of these components is not completely understood,but extensive ev...Cereal grains can contribute to maintain health and prevent chronic diseases by supplying biologically active components. The exact mechanism of action of these components is not completely understood,but extensive evidence suggests the antioxidants that are present in the grains are the likely source of benefits. These activities or properties might protect against coronary heart disease and diabetes. The relationships of complex carbohydrates,whole grain products and the prevention of diseases,including type2 diabetes mellitus and coronary heart disease continue to challenge the scientific community. Though cereal grains contribute to a healthy diet there are some people that can not tolerate the proteins present in the grain. This can lead to food allergies and when severe can be diagnosed as celiac disease.展开更多
Nanograins are characterized by a typical grain size from 1 to 100 nm. Molecular dynamics simulations have been carried out for the nanograin sphere with the diameters from 1.45 to 10.12 nm. We study the influence of ...Nanograins are characterized by a typical grain size from 1 to 100 nm. Molecular dynamics simulations have been carried out for the nanograin sphere with the diameters from 1.45 to 10.12 nm. We study the influence of grain size on structure and diffusion properties of the nanograins. The results reveal that as the grain size is reduced, the fraction of grain surface increases significantly, and the surface width is approximately constant; the mean atomic energy of the surface increases distinctly, but that of the grain interior varies insignificantly; the diffusion coefficient is increased sharply, and the relation of the diffusion coefficient and the grain size is close to exponential relation below 10 nm.展开更多
This study investigates the differences in microstructural control between cryogenic forging combined with pre-deformation(PCF)and traditional thermal forging(TTF)for 7050 aluminum forgings intended for aerospace appl...This study investigates the differences in microstructural control between cryogenic forging combined with pre-deformation(PCF)and traditional thermal forging(TTF)for 7050 aluminum forgings intended for aerospace applications.The PCF process,utilizing cryogenic deformation,significantly refines the coarse grains at the surface of the forgings,resulting in a finer and more uniform microstructure,thereby effectively addressing the issue of surface coarse grains associated with traditional methods.The findings indicate that the PCF process can accumulate higher stored energy,facilitating static recrystallization(SRX)during subsequent heat treatment and enhancing the microstructural uniformity.Utilizing various analytical techniques,including optical microscopy(OM),electron backscatter diffraction(EBSD),and transmission electron microscopy(TEM).This study reveals the superiority of the PCF process in terms of strain accumulation,dislocation density,and grain refinement.In conclusion,this method offers advantages in enhancing the performance and microstructural uniformity of 7050 aluminum forgings,presenting new opportunities for applications in the aluminum forging industry.展开更多
The influence of grain size or grain refinement on the corrosion of Zr alloy is clarified by employing a series of electrochemical analyses and characterization techniques.The corrosion resistance,as a function of exp...The influence of grain size or grain refinement on the corrosion of Zr alloy is clarified by employing a series of electrochemical analyses and characterization techniques.The corrosion resistance,as a function of exposure time,F−concentration,and solution temperatures,of Zr alloys with different grain sizes is ascertained.The results confirm that refining the grain size can effectively enhance the short-time corrosion properties of Zr alloy in HNO_(3) with F−.The fine grained Zr alloy(~10μm in diameter)consistently exhibits a lower corrosion current density,ranging from 18%to 46%lower than that of the coarse-grained Zr alloy(~44μm).The enhanced corrosion resistance is attributed to the high density grain boundaries,which promote oxide stability,and accelerate the creation of the protective layer.The high corrosion rate and pseudo-passivation behavior of Zr alloys in fluorinated nitric acid originate from the accelerated“dissolution-passivation”of the oxide film.However,the grain refinement does not provide enduring anti-corrosion for Zr alloys.To meet the operation of spent fuel reprocessing,additional systematic efforts are required to evaluate the long term effect of grain refinement.展开更多
An increase in RE element content in Mg alloys promotes the grain boundary precipitate,which affects the mechanical properties.However,the influence of grain boundary precipitates on microstructure of Mg-RE alloys dur...An increase in RE element content in Mg alloys promotes the grain boundary precipitate,which affects the mechanical properties.However,the influence of grain boundary precipitates on microstructure of Mg-RE alloys during ageing and their role on ductility of the aged alloy is unclear.In this work,hot extrusion and ageing treatment were performed for Mg-9Gd-2Y-xNd-0.2Zr(x=1 wt.%and 3 wt.%)alloys,and grain boundary precipitates were formed in the extruded Mg-9Gd-2Y-3Nd-0.2Zr alloy due to the increase of Nd content.The extruded alloys exhibit a complete dynamic recrystallization(DRX)microstructure and a texture with the<0001>orientation parallel to the extrusion direction(ED).In addition,a large amount of fiber microstructures distributed by the second phase along the ED were formed in the Mg-9Gd-2Y-3Nd-0.2Zr alloy,while only a small amount of the second phase was observed in the Mg-9Gd-2Y-1Nd-0.2Zr alloy.After ageing treatment,a large amount ofβ'phase precipitated inside the grains.The strength of the Mg-9Gd-2Y-1Nd-0.2Zr alloy increased from 202 MPa to 275 MPa but the elongation decreased from 12.8%to 2.6%,and the strength of the Mg-9Gd-2Y-3Nd-0.2Zr alloy increased from 212 MPa to 281 MPa but the elongation decreased from 13.7%to 6.2%.Among them,the Mg-9Gd-2Y-3Nd-0.2Zr alloy showed good overall mechanical properties,especially the elongation of the aged alloy was 58%higher than that of the Mg-9Gd-2Y-1Nd-0.2Zr alloy.The increase in ductility of the aged Mg-9Gd-2Y-3Nd-0.2Zr alloy attributed to the grain boundary precipitate promotes the formation of a large number of precipitation free zones(PFZs)with widths of 130-150 nm during ageing treatment.展开更多
The reverse design of solid rocket motor(SRM)propellant grain involves determining the grain geometry to closely match a predefined internal ballistic curve.While existing reverse design methods are feasible,they ofte...The reverse design of solid rocket motor(SRM)propellant grain involves determining the grain geometry to closely match a predefined internal ballistic curve.While existing reverse design methods are feasible,they often face challenges such as lengthy computation times and limited accuracy.To achieve rapid and accurate matching between the targeted ballistic curve and complex grain shape,this paper proposes a novel reverse design method for SRM propellant grain based on time-series data imaging and convolutional neural network(CNN).First,a finocyl grain shape-internal ballistic curve dataset is created using parametric modeling techniques to comprehensively cover the design space.Next,the internal ballistic time-series data is encoded into three-channel images,establishing a potential relationship between the ballistic curves and their image representations.A CNN is then constructed and trained using these encoded images.Once trained,the model enables efficient inference of propellant grain dimensions from a target internal ballistic curve.This paper conducts comparative experiments across various neural network models,validating the effectiveness of the feature extraction method that transforms internal ballistic time-series data into images,as well as its generalization capability across different CNN architectures.Ignition tests were performed based on the predicted propellant grain.The results demonstrate that the relative error between the experimental internal ballistic curves and the target curves is less than 5%,confirming the validity and feasibility of the proposed reverse design methodology.展开更多
This study examines the effects of friction stir welding(FSW)and post-weld heat treatment(PWHT)on the grain boundary character distribution and corrosion resistance of cross sectional(top and bottom)regions of nickel-...This study examines the effects of friction stir welding(FSW)and post-weld heat treatment(PWHT)on the grain boundary character distribution and corrosion resistance of cross sectional(top and bottom)regions of nickel-and molybdenum-free high-nitrogen austenitic stainless steel(HNASS).FSW at 400 rpm and 30 mm/min resulted in finer grains(4.18μm)and higher coincident site lattice(CSL)boundaries(32.3%)at the top of the stir zone(SZ)due to dynamic recrystallization(DRX).PWHT at 900℃for 1 h led to grain coarsening(12.91μm the bottom SZ)but enhanced CSL boundaries from 24.6%to 30.2%,improving grain boundary stability.PWHT reduced the kernel average misorientation(KAM)by 14.9%in the SZ-top layer and 20.4%in the SZ-bottom layer,accompanied by a 25%decrease in hardness in the SZ-top layer and 26.7%in the SZ-bottom layer,indicating strain recovery and reduced dislocation density.Potentiodynamic polarization tests(PDP)showed a 18%increase in pitting potential and a 76%reduction in corrosion rate after PWHT.The improvement in corrosion resistance is attributed to the increase inΣ3 twin boundaries,which enhance grain boundary stability and reduce susceptibility to localized corrosion.These findings highlight the role of PWHT in refining the microstructure and strengthening corrosion resistance,making HNASS a promising material for demanding applications.展开更多
The mechanical properties of many materials prepared by additive manufacturing technology have been greatly improved.High strength is attributed to grain refinement,formation of high density dislocation and existence ...The mechanical properties of many materials prepared by additive manufacturing technology have been greatly improved.High strength is attributed to grain refinement,formation of high density dislocation and existence of cellular structures with nanoscale during manufacturing.In addition,the super-saturated solid solution of elements in the matrix and the solid solution segregation along the wall of the cellular structures also promote the improvement of strength by enhancing dislocation pinning.Hence,the existence of cellular structure in grains leads to differences in the prediction of material strength by Hall-Petch relationship,and there is no unified calculation method to determine the d value as grain size or cell size.In this work,representative materials including austenite 316L SS were printed by selective laser melting(SLM),and the strength was predicted.The values of cell size and grain size were substituted into Hall-Petch formula,and the results showed that the calculation error for 316L is increased from 4.1%to 11.9%.Therefore,it is concluded that the strength predicted by grain size is more accurate than that predicted by cell size in additive manufacturing materials.When calculating the yield strength of laser additive manufacturing metal materials through the Hall-Petch formula,the grain size should be used as the basis for calculation.展开更多
To understand the solidification behavior of austenitic stainless steel in rotary electromagnetic-field, the influence of low-frequency rotary electromagnetic-field on solidification structure of austenitic stainless ...To understand the solidification behavior of austenitic stainless steel in rotary electromagnetic-field, the influence of low-frequency rotary electromagnetic-field on solidification structure of austenitic stainless steel in horizontal continuous casting was investigated based on industrial experiments. The results show that the solidification structure of austenitic stainless steel can be remarkably refined, the central porosity and shrinkage cavity can be remarkably decreased, and the equiaxed grains zone are enlarged by means of application of appropriate low-frequency electromagnetic-field parameters. The industrial trials verify that the stirring intensity of austenitic stainless steel should be higher compared with that of plain carbon steel. Electromagnetic stirring affects the macrostructure even if the average magnetic flux density of the electromagnetic stirring reaches 90 mT (amplitude reaches 141 mT) with the frequency of 3-4 Hz. Due to a higher viscosity, rotating speed of molten stainless steel is 20%-30% lower than that of molten carbon steel in the same magnetic flux density.展开更多
The experiment of ultrasonic treatment of roll casting aluminum strip on plane twin-roll cast-roller with double-heads ultrasonic tools was carried out, and the metallographic structure of the roll casting aluminum st...The experiment of ultrasonic treatment of roll casting aluminum strip on plane twin-roll cast-roller with double-heads ultrasonic tools was carried out, and the metallographic structure of the roll casting aluminum strip treated by ultrasonic was studied. The results show that ultrasonic treatment can refine the grain of the roll casting aluminum strips and make the structure of the strips more homogeneous. The effect is the best when the power of ultrasonic is 300 W and the incident angle of the guide rod is 45、. The mechanism of acoustic cavitations and acoustic flow on grain refinement was also discussed. The heat effect of intensity ultrasonic was studied. The present problems during ultrasonic roll casting process, such as the imperfect cooling system, the inaccurate calculation of ultrasonic energy, and the shape and position of the guide rod to be improved were pointed out.展开更多
基金Project(10A110) supported by Hunan Provincial Education Department of ChinaProject(2010JT4055) supported by Hunan Provincial Science & Technology Department of China
文摘Abstract: Daqu distiller's grains were co-fermented as raw materials by Trichoderma.koningii and Trichosporon cutaneum to produce microbial oils, which can provide raw materials for bio-diesel development. The single factor tests were used to investigate the effects of ratio of strains, inoculum size, culture temperature and culture time on the production of microbial oils. The best processing conditions were obtained by orthogonal test through measuring the content of microbial oils in product. The result shows that the microbial oils content of the co-fermented product under the ratio of Trichoderma.koningii to Trichosporon cutaneum of 1:1, the inoculum size of strains of 11% at 28 ℃ for 6 d is 7.15 g/L. It is shown that the production of microbial oils co-fermented by Trichoderma.koningii and Trichosporon cutaneum with Daqu distiller's grains is possible. The research provides a new idea for the reuse of Daqu distiller's grains and also provides a new way for the development of microbial oils.
文摘Cereal grains can contribute to maintain health and prevent chronic diseases by supplying biologically active components. The exact mechanism of action of these components is not completely understood,but extensive evidence suggests the antioxidants that are present in the grains are the likely source of benefits. These activities or properties might protect against coronary heart disease and diabetes. The relationships of complex carbohydrates,whole grain products and the prevention of diseases,including type2 diabetes mellitus and coronary heart disease continue to challenge the scientific community. Though cereal grains contribute to a healthy diet there are some people that can not tolerate the proteins present in the grain. This can lead to food allergies and when severe can be diagnosed as celiac disease.
基金supported by the National Naturl Science Foundation of China(No.10172088)the Potdoctoral Saience Foundation of China
文摘Nanograins are characterized by a typical grain size from 1 to 100 nm. Molecular dynamics simulations have been carried out for the nanograin sphere with the diameters from 1.45 to 10.12 nm. We study the influence of grain size on structure and diffusion properties of the nanograins. The results reveal that as the grain size is reduced, the fraction of grain surface increases significantly, and the surface width is approximately constant; the mean atomic energy of the surface increases distinctly, but that of the grain interior varies insignificantly; the diffusion coefficient is increased sharply, and the relation of the diffusion coefficient and the grain size is close to exponential relation below 10 nm.
基金Project(2021GK1040) supported by the Major Projects of Scientific and Technology Innovation of Hunan Province,ChinaProjects(52375398,52171018) supported by the National Natural Science Foundation of China+1 种基金Project(Kfkt2023-09) supported by the Open Research Fund of State Key Laboratory of Precision Manufacturing for Extreme Service Performance,Central South University,ChinaProject(E2021203059) supported by the Natural Science Foundation of Hebei Province,China。
文摘This study investigates the differences in microstructural control between cryogenic forging combined with pre-deformation(PCF)and traditional thermal forging(TTF)for 7050 aluminum forgings intended for aerospace applications.The PCF process,utilizing cryogenic deformation,significantly refines the coarse grains at the surface of the forgings,resulting in a finer and more uniform microstructure,thereby effectively addressing the issue of surface coarse grains associated with traditional methods.The findings indicate that the PCF process can accumulate higher stored energy,facilitating static recrystallization(SRX)during subsequent heat treatment and enhancing the microstructural uniformity.Utilizing various analytical techniques,including optical microscopy(OM),electron backscatter diffraction(EBSD),and transmission electron microscopy(TEM).This study reveals the superiority of the PCF process in terms of strain accumulation,dislocation density,and grain refinement.In conclusion,this method offers advantages in enhancing the performance and microstructural uniformity of 7050 aluminum forgings,presenting new opportunities for applications in the aluminum forging industry.
基金Project(U2067217)supported by the National Natural Science Foundation of ChinaProject(SASTIND)supported by the State Administration of Science,Technology and Industry for National Defense,ChinaProject(2020M683572)supported by China Postdoctoral Science Foundation。
文摘The influence of grain size or grain refinement on the corrosion of Zr alloy is clarified by employing a series of electrochemical analyses and characterization techniques.The corrosion resistance,as a function of exposure time,F−concentration,and solution temperatures,of Zr alloys with different grain sizes is ascertained.The results confirm that refining the grain size can effectively enhance the short-time corrosion properties of Zr alloy in HNO_(3) with F−.The fine grained Zr alloy(~10μm in diameter)consistently exhibits a lower corrosion current density,ranging from 18%to 46%lower than that of the coarse-grained Zr alloy(~44μm).The enhanced corrosion resistance is attributed to the high density grain boundaries,which promote oxide stability,and accelerate the creation of the protective layer.The high corrosion rate and pseudo-passivation behavior of Zr alloys in fluorinated nitric acid originate from the accelerated“dissolution-passivation”of the oxide film.However,the grain refinement does not provide enduring anti-corrosion for Zr alloys.To meet the operation of spent fuel reprocessing,additional systematic efforts are required to evaluate the long term effect of grain refinement.
基金Project(2021YFB3701103) supported by the National Key R&D Program of China。
文摘An increase in RE element content in Mg alloys promotes the grain boundary precipitate,which affects the mechanical properties.However,the influence of grain boundary precipitates on microstructure of Mg-RE alloys during ageing and their role on ductility of the aged alloy is unclear.In this work,hot extrusion and ageing treatment were performed for Mg-9Gd-2Y-xNd-0.2Zr(x=1 wt.%and 3 wt.%)alloys,and grain boundary precipitates were formed in the extruded Mg-9Gd-2Y-3Nd-0.2Zr alloy due to the increase of Nd content.The extruded alloys exhibit a complete dynamic recrystallization(DRX)microstructure and a texture with the<0001>orientation parallel to the extrusion direction(ED).In addition,a large amount of fiber microstructures distributed by the second phase along the ED were formed in the Mg-9Gd-2Y-3Nd-0.2Zr alloy,while only a small amount of the second phase was observed in the Mg-9Gd-2Y-1Nd-0.2Zr alloy.After ageing treatment,a large amount ofβ'phase precipitated inside the grains.The strength of the Mg-9Gd-2Y-1Nd-0.2Zr alloy increased from 202 MPa to 275 MPa but the elongation decreased from 12.8%to 2.6%,and the strength of the Mg-9Gd-2Y-3Nd-0.2Zr alloy increased from 212 MPa to 281 MPa but the elongation decreased from 13.7%to 6.2%.Among them,the Mg-9Gd-2Y-3Nd-0.2Zr alloy showed good overall mechanical properties,especially the elongation of the aged alloy was 58%higher than that of the Mg-9Gd-2Y-1Nd-0.2Zr alloy.The increase in ductility of the aged Mg-9Gd-2Y-3Nd-0.2Zr alloy attributed to the grain boundary precipitate promotes the formation of a large number of precipitation free zones(PFZs)with widths of 130-150 nm during ageing treatment.
文摘The reverse design of solid rocket motor(SRM)propellant grain involves determining the grain geometry to closely match a predefined internal ballistic curve.While existing reverse design methods are feasible,they often face challenges such as lengthy computation times and limited accuracy.To achieve rapid and accurate matching between the targeted ballistic curve and complex grain shape,this paper proposes a novel reverse design method for SRM propellant grain based on time-series data imaging and convolutional neural network(CNN).First,a finocyl grain shape-internal ballistic curve dataset is created using parametric modeling techniques to comprehensively cover the design space.Next,the internal ballistic time-series data is encoded into three-channel images,establishing a potential relationship between the ballistic curves and their image representations.A CNN is then constructed and trained using these encoded images.Once trained,the model enables efficient inference of propellant grain dimensions from a target internal ballistic curve.This paper conducts comparative experiments across various neural network models,validating the effectiveness of the feature extraction method that transforms internal ballistic time-series data into images,as well as its generalization capability across different CNN architectures.Ignition tests were performed based on the predicted propellant grain.The results demonstrate that the relative error between the experimental internal ballistic curves and the target curves is less than 5%,confirming the validity and feasibility of the proposed reverse design methodology.
文摘This study examines the effects of friction stir welding(FSW)and post-weld heat treatment(PWHT)on the grain boundary character distribution and corrosion resistance of cross sectional(top and bottom)regions of nickel-and molybdenum-free high-nitrogen austenitic stainless steel(HNASS).FSW at 400 rpm and 30 mm/min resulted in finer grains(4.18μm)and higher coincident site lattice(CSL)boundaries(32.3%)at the top of the stir zone(SZ)due to dynamic recrystallization(DRX).PWHT at 900℃for 1 h led to grain coarsening(12.91μm the bottom SZ)but enhanced CSL boundaries from 24.6%to 30.2%,improving grain boundary stability.PWHT reduced the kernel average misorientation(KAM)by 14.9%in the SZ-top layer and 20.4%in the SZ-bottom layer,accompanied by a 25%decrease in hardness in the SZ-top layer and 26.7%in the SZ-bottom layer,indicating strain recovery and reduced dislocation density.Potentiodynamic polarization tests(PDP)showed a 18%increase in pitting potential and a 76%reduction in corrosion rate after PWHT.The improvement in corrosion resistance is attributed to the increase inΣ3 twin boundaries,which enhance grain boundary stability and reduce susceptibility to localized corrosion.These findings highlight the role of PWHT in refining the microstructure and strengthening corrosion resistance,making HNASS a promising material for demanding applications.
基金Projects(51505166,51871249)supported by the National Natural Science Foundation of ChinaProject(Guike AB19050002)supported by the Guangxi Key Research and Development Program,China+1 种基金Project(2020JJ2046)supported by the Hunan Science Fund for Distinguished Young Scholars,ChinaProject(2020WK2027)supported by the Hunan Key R&D Plan,China。
文摘The mechanical properties of many materials prepared by additive manufacturing technology have been greatly improved.High strength is attributed to grain refinement,formation of high density dislocation and existence of cellular structures with nanoscale during manufacturing.In addition,the super-saturated solid solution of elements in the matrix and the solid solution segregation along the wall of the cellular structures also promote the improvement of strength by enhancing dislocation pinning.Hence,the existence of cellular structure in grains leads to differences in the prediction of material strength by Hall-Petch relationship,and there is no unified calculation method to determine the d value as grain size or cell size.In this work,representative materials including austenite 316L SS were printed by selective laser melting(SLM),and the strength was predicted.The values of cell size and grain size were substituted into Hall-Petch formula,and the results showed that the calculation error for 316L is increased from 4.1%to 11.9%.Therefore,it is concluded that the strength predicted by grain size is more accurate than that predicted by cell size in additive manufacturing materials.When calculating the yield strength of laser additive manufacturing metal materials through the Hall-Petch formula,the grain size should be used as the basis for calculation.
基金Project(CSTC2007BB4216) supported by the Natural Science Foundation of Chongqing,China
文摘To understand the solidification behavior of austenitic stainless steel in rotary electromagnetic-field, the influence of low-frequency rotary electromagnetic-field on solidification structure of austenitic stainless steel in horizontal continuous casting was investigated based on industrial experiments. The results show that the solidification structure of austenitic stainless steel can be remarkably refined, the central porosity and shrinkage cavity can be remarkably decreased, and the equiaxed grains zone are enlarged by means of application of appropriate low-frequency electromagnetic-field parameters. The industrial trials verify that the stirring intensity of austenitic stainless steel should be higher compared with that of plain carbon steel. Electromagnetic stirring affects the macrostructure even if the average magnetic flux density of the electromagnetic stirring reaches 90 mT (amplitude reaches 141 mT) with the frequency of 3-4 Hz. Due to a higher viscosity, rotating speed of molten stainless steel is 20%-30% lower than that of molten carbon steel in the same magnetic flux density.
基金Projects(IRT0549) supported by Program for Changjiang Scholars and Innovative Research Team in University, China
文摘The experiment of ultrasonic treatment of roll casting aluminum strip on plane twin-roll cast-roller with double-heads ultrasonic tools was carried out, and the metallographic structure of the roll casting aluminum strip treated by ultrasonic was studied. The results show that ultrasonic treatment can refine the grain of the roll casting aluminum strips and make the structure of the strips more homogeneous. The effect is the best when the power of ultrasonic is 300 W and the incident angle of the guide rod is 45、. The mechanism of acoustic cavitations and acoustic flow on grain refinement was also discussed. The heat effect of intensity ultrasonic was studied. The present problems during ultrasonic roll casting process, such as the imperfect cooling system, the inaccurate calculation of ultrasonic energy, and the shape and position of the guide rod to be improved were pointed out.