To get a deep understanding of the evolution behavior of equiaxedαphase in Ti−8Al−1Mo−1V alloy during annealing,its static coarsening mechanism was studied based on the calculations of coarsening exponent n and the a...To get a deep understanding of the evolution behavior of equiaxedαphase in Ti−8Al−1Mo−1V alloy during annealing,its static coarsening mechanism was studied based on the calculations of coarsening exponent n and the activation energy forαboundary migration.The result of n=6 indicates a special coarsening mechanism of equiaxedαphase.The activation energy forαboundary migration is calculated to be 138 kJ/mol,which is close to the activation energy for grain growth of pureα-Ti.It is revealed that the coarsening of equiaxedαcan be mainly attributed to the self-diffusion of Ti atoms across theα/αboundaries.Based on the experimental findings,a static coarsening kinetics model of equiaxedαgrains in theα+βfield is established.At last,the effects of the coarsening behavior of equiaxedαon tensile properties were studied.展开更多
The mechanism of the staple yarn's drafting waves during roller drafting is analyzed in this paper.It's concluded that the dynamic friction coefficient is greater than the static friction coefficient on the fr...The mechanism of the staple yarn's drafting waves during roller drafting is analyzed in this paper.It's concluded that the dynamic friction coefficient is greater than the static friction coefficient on the friction behavior of fibers,and the difference is largely responsible for the "stick-slip" motion of fibers which causes the drafting waves during drafting.In this paper,it's expected that when a high frequency undulating wave is imposed on the fiber strand in the drafting zone of roller system,the friction among fibers is dominated by the dynamic friction rather than the static friction,and thus the "stick-slip" motion will be eliminated.As a result,the fiber binding effect causing drafting waves can be significantly reduced.This hypothesis is verified by an experiment,and it can be applied in developing new spinning drafting device.展开更多
基金financial supports from the China Scholarship Council(No.201906935013)the National Natural Science Foundation of China(No.51801132).
文摘To get a deep understanding of the evolution behavior of equiaxedαphase in Ti−8Al−1Mo−1V alloy during annealing,its static coarsening mechanism was studied based on the calculations of coarsening exponent n and the activation energy forαboundary migration.The result of n=6 indicates a special coarsening mechanism of equiaxedαphase.The activation energy forαboundary migration is calculated to be 138 kJ/mol,which is close to the activation energy for grain growth of pureα-Ti.It is revealed that the coarsening of equiaxedαcan be mainly attributed to the self-diffusion of Ti atoms across theα/αboundaries.Based on the experimental findings,a static coarsening kinetics model of equiaxedαgrains in theα+βfield is established.At last,the effects of the coarsening behavior of equiaxedαon tensile properties were studied.
基金National Natural Science Foundation of China(No.50775034)
文摘The mechanism of the staple yarn's drafting waves during roller drafting is analyzed in this paper.It's concluded that the dynamic friction coefficient is greater than the static friction coefficient on the friction behavior of fibers,and the difference is largely responsible for the "stick-slip" motion of fibers which causes the drafting waves during drafting.In this paper,it's expected that when a high frequency undulating wave is imposed on the fiber strand in the drafting zone of roller system,the friction among fibers is dominated by the dynamic friction rather than the static friction,and thus the "stick-slip" motion will be eliminated.As a result,the fiber binding effect causing drafting waves can be significantly reduced.This hypothesis is verified by an experiment,and it can be applied in developing new spinning drafting device.
