The damping behavior of extruded Mg-xY(x=0.5,1.0,3.0 wt.%)sheets were investigated in detail concerning the effects of Y addition and temperature,and the relationship between damping capacity and yield strength was di...The damping behavior of extruded Mg-xY(x=0.5,1.0,3.0 wt.%)sheets were investigated in detail concerning the effects of Y addition and temperature,and the relationship between damping capacity and yield strength was discussed.At room temperature(RT),with Y content increasing from 0.5%to 3.0%,the damping capacity(Q-1)significantly decreased from 0.037 to 0.015.For all the studied sheets,the relationship between strain amplitude and Q-1 fitted well with the Granato and Liicke(G-L)dislocation damping model.With temperature increased,the G-L plots deviated from linearity indicating that the dislocation damping was not the only dominate mechanism,and the grain boundary sliding(GBS)could contribute to damping capacity.Consequently,the Q-1 increased remarkably above the critical temperature,and the critical temperature increased significantly from 50℃ to 290℃ with increasing Y contents from 0 to 3.0wt.%.This result implied that the segregation of Y solutes at grain boundary could depress the GBS,which was consistent with the recent finding of segregation tendency for rare-earth solutes.The extruded Mg-IY sheet exhibited slightly higher yield strength(Rp0.2)and Q-1 comparing with high-damping Mg-0.6Zr at RT.At an elevated temperature of 325℃,the Mg-IY sheet had similar Q-1 but over 3 times larger Rp0.2 than that of the pure Mg.The present study indicated that the extruded Mg-Y based alloys exhibited promising potential for developing high-performance damping alloys,especially for the elevated-temperature application.展开更多
Strengthening in Inconel 718 superalloy is derived from dislocation interaction withγ"precipitates,which exist in disk-shaped three possible orientation variants with their{100}habit plane normal to each other.T...Strengthening in Inconel 718 superalloy is derived from dislocation interaction withγ"precipitates,which exist in disk-shaped three possible orientation variants with their{100}habit plane normal to each other.The interactions between dislocations andγ"precipitates vary according to theγ"orienta-tion variants,which makes the deformation behaviour complicated and difficult to reveal experimentally.In this work,γ"variant distributions of Inconel 718 samples were tailored by ageing heat treatment under either tensile or compressive stress.Theγ"variant-sensitive deformation behaviours were then studied by in situ tensile tests via neutron diffraction at room temperature.It is demonstrated that yield-ing first takes place in grains oriented with<110>parallel to the loading direction.An identical lattice strain response to applied stress of both theγmatrix and theγ"precipitates was observed during yield-ing,suggesting that dislocations shearing through theγ"precipitates is predominant at this stage.Vari-ations in yield strength for samples with differentγ"variant distributions were observed,which can be attributed to different strengthening that arises from interactions between dislocation and differentγ"variants.展开更多
基金This work was supported by National Natural Science Foundation of China(Nos.51401172 and 51601003)National University Student Innovation Experimental Project(No.201710613005)Sichuan Science and Technology Program(No.2019YJ0238).
文摘The damping behavior of extruded Mg-xY(x=0.5,1.0,3.0 wt.%)sheets were investigated in detail concerning the effects of Y addition and temperature,and the relationship between damping capacity and yield strength was discussed.At room temperature(RT),with Y content increasing from 0.5%to 3.0%,the damping capacity(Q-1)significantly decreased from 0.037 to 0.015.For all the studied sheets,the relationship between strain amplitude and Q-1 fitted well with the Granato and Liicke(G-L)dislocation damping model.With temperature increased,the G-L plots deviated from linearity indicating that the dislocation damping was not the only dominate mechanism,and the grain boundary sliding(GBS)could contribute to damping capacity.Consequently,the Q-1 increased remarkably above the critical temperature,and the critical temperature increased significantly from 50℃ to 290℃ with increasing Y contents from 0 to 3.0wt.%.This result implied that the segregation of Y solutes at grain boundary could depress the GBS,which was consistent with the recent finding of segregation tendency for rare-earth solutes.The extruded Mg-IY sheet exhibited slightly higher yield strength(Rp0.2)and Q-1 comparing with high-damping Mg-0.6Zr at RT.At an elevated temperature of 325℃,the Mg-IY sheet had similar Q-1 but over 3 times larger Rp0.2 than that of the pure Mg.The present study indicated that the extruded Mg-Y based alloys exhibited promising potential for developing high-performance damping alloys,especially for the elevated-temperature application.
基金support from the Guangdong Introducing Innovative and Entrepreneurial Teams(No.2016ZT06G025)and the financial support from the Centre for Doctoral Training in Innovative Metal Processing(IMPaCT)funded by the UK Engineering and Physical Sciences Research Council(EPSRC,No.EP/L016206/1).The authors also acknowledge useful discussions by Dr.Xingzhong Liang and the allocation of beam time(RB1820207)at ENGIN-X,ISIS,Rutherford Appleton Labora-tory.Chinnapat Panwisawas would like to acknowledge the funding from Innovation Fellowship by EPSRC,UK Research and Innovation(UKRI,No.EP/S000828/2).Shuyan Zhang gratefully acknowledges the support from the Guangdong Major Project of Basic and Ap-plied Basic Research(No.2020B0301030001)and the Strategic Pri-ority Research Program of the Chinese Academy of Sciences(No.XDC04000000).
文摘Strengthening in Inconel 718 superalloy is derived from dislocation interaction withγ"precipitates,which exist in disk-shaped three possible orientation variants with their{100}habit plane normal to each other.The interactions between dislocations andγ"precipitates vary according to theγ"orienta-tion variants,which makes the deformation behaviour complicated and difficult to reveal experimentally.In this work,γ"variant distributions of Inconel 718 samples were tailored by ageing heat treatment under either tensile or compressive stress.Theγ"variant-sensitive deformation behaviours were then studied by in situ tensile tests via neutron diffraction at room temperature.It is demonstrated that yield-ing first takes place in grains oriented with<110>parallel to the loading direction.An identical lattice strain response to applied stress of both theγmatrix and theγ"precipitates was observed during yield-ing,suggesting that dislocations shearing through theγ"precipitates is predominant at this stage.Vari-ations in yield strength for samples with differentγ"variant distributions were observed,which can be attributed to different strengthening that arises from interactions between dislocation and differentγ"variants.
