The dynamic mechanical analyzer(DMA)was applied to investigate the damping properties of Mg-Cu based alloys.The results show that the as-cast hypoeutectic Mg-Cu binary alloys exhibit ultra-high damping capacities,whil...The dynamic mechanical analyzer(DMA)was applied to investigate the damping properties of Mg-Cu based alloys.The results show that the as-cast hypoeutectic Mg-Cu binary alloys exhibit ultra-high damping capacities,while the eutectic Mg-Cu alloy exhibits low damping capacity.The strain amplitude dependent damping performance reveals that the dislocation damping mainly dominates in Mg-Cu alloys.Furthermore,the influence of eutectic phase on damping mechanisms of Mg-Cu binary alloys was discussed in detail and the effect of Si addition on the damping of Mg-1%Cu based alloy was also reported.Two damping peaks are observed on the temperature dependent spectrum of Mg-Cu based alloys.One is located at room temperature,which is dislocation related peak;and the other is located at moderate temperature,which is caused by the grain boundary sliding.展开更多
The damping capacities (Q-1) of high silicon (6wt%) Zinc-27wt% Aluminia alloy prepared by spray deposition and conventional casting process were investigated. Three methods, free-decay, half-power band width and phase...The damping capacities (Q-1) of high silicon (6wt%) Zinc-27wt% Aluminia alloy prepared by spray deposition and conventional casting process were investigated. Three methods, free-decay, half-power band width and phase angles difference, have been ased to measure the damping capacities of the experimental materiale. The experimental results indicate that the damping capacity of spray deposited material is 3.7times larger than that of the conventional casting alloy ZA27 The machanism for its improvement was aiso investigated from a microstructvre viempoint.展开更多
Alloying is a good approach to increasing its strength but leads to a reduction of damping to pure magnesium.Classifying the alloying characteristics of various alloying elements in magnesium alloys and their combined...Alloying is a good approach to increasing its strength but leads to a reduction of damping to pure magnesium.Classifying the alloying characteristics of various alloying elements in magnesium alloys and their combined effects on the damping and mechanical properties of magnesium alloys is important.In this paper,the properties of the Mg-0.6wt%X binary alloys were analyzed through strength measurements and dynamic mechanical analysis.The effects of foreign atoms on solid-solution strengthening and dislocation damping were studied comprehensively.The effect of solid solubility on damping capacity can be considered from two perspectives:the effect of single solid-solution atoms on the damping capacities of the alloy,and the effect of solubility on the damping capacities of the alloy.The results provide significant information that is useful in developing high-strength,high-damping magnesium alloys.This study will provide scientific guidance regarding the development of new types of damping magnesium alloys.展开更多
High manganese steel has wide prospects in industry due to their excellent mechanical and damping properties. The quenching structures of high manganese steel are ε-martensite, γ-austenite and α'-martensite. Re...High manganese steel has wide prospects in industry due to their excellent mechanical and damping properties. The quenching structures of high manganese steel are ε-martensite, γ-austenite and α'-martensite. Researches show that the damping properties of high manganese steel are related to these microstructures. Besides, there are many ways to improve the damping property of damping alloys. This paper reviews the damping mechanism and the influences of the ad-dition of alloying elements, heat treatment, pre-deformation and other factors on their damping performance, hoping to provide methods and ideas for the study of damping properties of high manganese steel. .展开更多
A series of new Cr-Mn-Fe-V-Cu high-entropy alloys were prepared by arc melting and suction casting.It is found that with the addition of Cu, the structure of the alloys evolved from BCC ＋ BCC1 phases to BCC ＋ FCC ph...A series of new Cr-Mn-Fe-V-Cu high-entropy alloys were prepared by arc melting and suction casting.It is found that with the addition of Cu, the structure of the alloys evolved from BCC ＋ BCC1 phases to BCC ＋ FCC phases. With increase of Cu, the volume fraction of the Cu-Mn-rich FCC phase increased, and the morphology of the FCC phase transformed from granular particles to long strips and blocks. Compared with other reported HEAs, the Cr-Mn-Fe-V-Cu HEAs exhibit a good balance between strength and ductility. The CrMn0.3 FeVCu0.06 alloy with granular FCC particles exhibits the highest compressive yield strength（1273 MPa） and excellent ductility（εf= 50.7%）. Quantitative calculations for different strengthening mechanisms demonstrate that dislocation and precipitate strengthening are responsible for high strength of the CrMn0.3 FeVCu0.06 alloy, while the solid solution strengthening effect is very low because of its small atomic-size difference. In addition, the CrMn0.3 FeVCu0.06 alloy exhibits good damping capacity due to its high dislocation and interface damping effects. Therefore, the dislocation density and distribution of FCC phase are the crucial factors for improvement of both mechanical properties and damping capacity of the HEAs.展开更多
TiNi-based shape memory alloys(SMAs)have been used as damping materials to eliminate noise and mechanical vibration.However,their application is limited by low working temperatures and damping capacity.In this work,tw...TiNi-based shape memory alloys(SMAs)have been used as damping materials to eliminate noise and mechanical vibration.However,their application is limited by low working temperatures and damping capacity.In this work,two novel Ti-Zr-Hf-Ni-Co-Cu high entropy shape memory alloys(HESMAs)with different transformation temperatures and damping properties were investigated.The results show that Ti_(25)Zr_(8)Hf_(17)Ni_(30)Co_(5)Cu_(15) has superior damping performance arising from martensitic transformation,shape memory effect(thermal cycle at constant load)as well as superelasticity.Compared to traditional TiNi-based SMAs,the as-cast HESMAs exhibit a much higher ultrahigh yield strength(∼2 GPa)and storage modulus(∼50 GPa).The high configuration entropy of the HESMAs with high uneven internal stress and severe lattice distortion is revealed as the underlying mechanisms governing distinctive damping performance.The effects of high configuration entropy and microheterogeneity on the martensitic transforma-tion behavior and damping performance of HESMAs are clarified in this work,which provides a basis for designing alloys with superior damping properties.展开更多
Mn-Cu alloys could exhibit high damping ability and excellent mechanical properties after proper heat treatment. In order to reduce the influence of impurity elements on damping capacity of Mn-Cu alloys, rare ele- men...Mn-Cu alloys could exhibit high damping ability and excellent mechanical properties after proper heat treatment. In order to reduce the influence of impurity elements on damping capacity of Mn-Cu alloys, rare ele- ment cerium （Ce） was added into MnCuNiFe alloys. It is indicated that the contents of C, S and Si which have adverse effects on the damping capacity decrease and the grains are refined with the Ce content increasing. The microstructure of the MnCuNiFeCe alloy was investigated by X-ray diffraction （XRD）, scanning electron microscope （SEM） and transmission electron microscopy （TEM）. The damping ability （tane） of the alloy was characterized by dynamical mechanical analyzer （DMA）. It is found that the damping ability （tane） retains a very high level which is all above 0.05 from the temperature of -50 to 75 ℃ with the addition of Ce element. It is expected that the Ce alloying MnCuNiFe alloy with refined grains could find wide applications in the field of industry.展开更多
基金Project(50671083)supported by the National Natural Science Foundation of China
文摘The dynamic mechanical analyzer(DMA)was applied to investigate the damping properties of Mg-Cu based alloys.The results show that the as-cast hypoeutectic Mg-Cu binary alloys exhibit ultra-high damping capacities,while the eutectic Mg-Cu alloy exhibits low damping capacity.The strain amplitude dependent damping performance reveals that the dislocation damping mainly dominates in Mg-Cu alloys.Furthermore,the influence of eutectic phase on damping mechanisms of Mg-Cu binary alloys was discussed in detail and the effect of Si addition on the damping of Mg-1%Cu based alloy was also reported.Two damping peaks are observed on the temperature dependent spectrum of Mg-Cu based alloys.One is located at room temperature,which is dislocation related peak;and the other is located at moderate temperature,which is caused by the grain boundary sliding.
文摘The damping capacities (Q-1) of high silicon (6wt%) Zinc-27wt% Aluminia alloy prepared by spray deposition and conventional casting process were investigated. Three methods, free-decay, half-power band width and phase angles difference, have been ased to measure the damping capacities of the experimental materiale. The experimental results indicate that the damping capacity of spray deposited material is 3.7times larger than that of the conventional casting alloy ZA27 The machanism for its improvement was aiso investigated from a microstructvre viempoint.
基金financially supported by the National Natural Science Foundation of China(Nos.51361010 and 51665012)the Jiangxi Province Science Fund for Distinguished Young Scholars(Nos.20171BCB23061 and 2018ACB21020)
文摘Alloying is a good approach to increasing its strength but leads to a reduction of damping to pure magnesium.Classifying the alloying characteristics of various alloying elements in magnesium alloys and their combined effects on the damping and mechanical properties of magnesium alloys is important.In this paper,the properties of the Mg-0.6wt%X binary alloys were analyzed through strength measurements and dynamic mechanical analysis.The effects of foreign atoms on solid-solution strengthening and dislocation damping were studied comprehensively.The effect of solid solubility on damping capacity can be considered from two perspectives:the effect of single solid-solution atoms on the damping capacities of the alloy,and the effect of solubility on the damping capacities of the alloy.The results provide significant information that is useful in developing high-strength,high-damping magnesium alloys.This study will provide scientific guidance regarding the development of new types of damping magnesium alloys.
文摘High manganese steel has wide prospects in industry due to their excellent mechanical and damping properties. The quenching structures of high manganese steel are ε-martensite, γ-austenite and α'-martensite. Researches show that the damping properties of high manganese steel are related to these microstructures. Besides, there are many ways to improve the damping property of damping alloys. This paper reviews the damping mechanism and the influences of the ad-dition of alloying elements, heat treatment, pre-deformation and other factors on their damping performance, hoping to provide methods and ideas for the study of damping properties of high manganese steel. .
基金support with testing materials and facilities from the Interdisciplinary Research Center for Advanced Structural and Biomaterials, Beihang University
文摘A series of new Cr-Mn-Fe-V-Cu high-entropy alloys were prepared by arc melting and suction casting.It is found that with the addition of Cu, the structure of the alloys evolved from BCC ＋ BCC1 phases to BCC ＋ FCC phases. With increase of Cu, the volume fraction of the Cu-Mn-rich FCC phase increased, and the morphology of the FCC phase transformed from granular particles to long strips and blocks. Compared with other reported HEAs, the Cr-Mn-Fe-V-Cu HEAs exhibit a good balance between strength and ductility. The CrMn0.3 FeVCu0.06 alloy with granular FCC particles exhibits the highest compressive yield strength（1273 MPa） and excellent ductility（εf= 50.7%）. Quantitative calculations for different strengthening mechanisms demonstrate that dislocation and precipitate strengthening are responsible for high strength of the CrMn0.3 FeVCu0.06 alloy, while the solid solution strengthening effect is very low because of its small atomic-size difference. In addition, the CrMn0.3 FeVCu0.06 alloy exhibits good damping capacity due to its high dislocation and interface damping effects. Therefore, the dislocation density and distribution of FCC phase are the crucial factors for improvement of both mechanical properties and damping capacity of the HEAs.
基金supported by the National Natural Science Foundation of China (NSFC) (Grant Nos.51971178,52271153 and 51871132)the Natural Science Basic Research Plan for Distinguished Young Scholars in Shaanxi Province (Grant No.2021JC-12)+1 种基金the Natural Science Foundation of Chongqing (Grant No.cstc2020jcyj-jqX0001)the Youth Innovation Promotion Association CAS (2021188).
文摘TiNi-based shape memory alloys(SMAs)have been used as damping materials to eliminate noise and mechanical vibration.However,their application is limited by low working temperatures and damping capacity.In this work,two novel Ti-Zr-Hf-Ni-Co-Cu high entropy shape memory alloys(HESMAs)with different transformation temperatures and damping properties were investigated.The results show that Ti_(25)Zr_(8)Hf_(17)Ni_(30)Co_(5)Cu_(15) has superior damping performance arising from martensitic transformation,shape memory effect(thermal cycle at constant load)as well as superelasticity.Compared to traditional TiNi-based SMAs,the as-cast HESMAs exhibit a much higher ultrahigh yield strength(∼2 GPa)and storage modulus(∼50 GPa).The high configuration entropy of the HESMAs with high uneven internal stress and severe lattice distortion is revealed as the underlying mechanisms governing distinctive damping performance.The effects of high configuration entropy and microheterogeneity on the martensitic transforma-tion behavior and damping performance of HESMAs are clarified in this work,which provides a basis for designing alloys with superior damping properties.
基金financially supported by Beijing Natural Science Foundation (No. 2142037)
文摘Mn-Cu alloys could exhibit high damping ability and excellent mechanical properties after proper heat treatment. In order to reduce the influence of impurity elements on damping capacity of Mn-Cu alloys, rare ele- ment cerium （Ce） was added into MnCuNiFe alloys. It is indicated that the contents of C, S and Si which have adverse effects on the damping capacity decrease and the grains are refined with the Ce content increasing. The microstructure of the MnCuNiFeCe alloy was investigated by X-ray diffraction （XRD）, scanning electron microscope （SEM） and transmission electron microscopy （TEM）. The damping ability （tane） of the alloy was characterized by dynamical mechanical analyzer （DMA）. It is found that the damping ability （tane） retains a very high level which is all above 0.05 from the temperature of -50 to 75 ℃ with the addition of Ce element. It is expected that the Ce alloying MnCuNiFe alloy with refined grains could find wide applications in the field of industry.
