The macrostructure and properties of the thin walled copper tube prepared by the downward continuous unidirectional solidification （DCUS） method were studied. The result shows that the macrostructure is closely rela...The macrostructure and properties of the thin walled copper tube prepared by the downward continuous unidirectional solidification （DCUS） method were studied. The result shows that the macrostructure is closely related to the solid-liquid interface profile, which is influenced by the distance between the cooling water location and the solidification front. The mechanical properties of the thin walled copper tube prepared by the DCUS method are near those of the normal cast copper, and it has good relative density, electrical conductivity, and elongation, which are not greatly affected by casting speed. The thin walled copper tube prepared by the DCUS method also has good processing properties that can be taken to further drawing procedures directly without an intermediate process, and obtains good mechanical properties with the total processing rate of 89.8%.展开更多
The effects of Ce addition(310 ppm and 1500 ppm)on the microstructure,texture and properties of ultrahigh-purity copper(99.99999%)were systematically studied using scanning electron microscopy(SEM),transmission electr...The effects of Ce addition(310 ppm and 1500 ppm)on the microstructure,texture and properties of ultrahigh-purity copper(99.99999%)were systematically studied using scanning electron microscopy(SEM),transmission electron microscopy(TEM)and electron backscattered diffraction(EBSD)analyses,combined with the microhardness and conductivity tests.Regarding the microstructure of the as-cast and as-extruded samples,the addition of Ce refines the grain size of the ultrahigh-purity copper and the refinement effect of 310Ce alloy is greater than that of 1500Ce alloy.This is due to the stronger compone nt supercooling and the accele rated recrystallization caused by lower Ce co ntent.In addition,Ce can react with Cu to form the Cu-Ce eutectic phases,which are deformable during the hot deformation.Furthermore,the added Ce can weaken the texture,showing a variation of brass recrystallization(BR),rotated cube,copper and S texture components,which depends on the recrystallization,the particle stimulated nucleation(PSN)as well as the stacking fault energy(SFE).Most remarkably,the introduction of Ce enhances the hardness of the ultrahigh-purity copper without obviously reducing its conductivity.The major{111}orientations and the stress distributions are responsible for such a superior conductivity of the Ce-containing alloys.展开更多
目的建立定量加酸-非线性拟合测定中性脱脂剂浓度的快速检测方法,解决滴定法和重量法在准确度和检测效率上不足的问题。方法采用脱脂剂原液配制成不同浓度的工作曲线溶液,在其中加入定量的酸后测定其pH值,将测得的pH值与脱脂剂浓度采用...目的建立定量加酸-非线性拟合测定中性脱脂剂浓度的快速检测方法,解决滴定法和重量法在准确度和检测效率上不足的问题。方法采用脱脂剂原液配制成不同浓度的工作曲线溶液,在其中加入定量的酸后测定其pH值,将测得的pH值与脱脂剂浓度采用非线性拟合得出关系函数,进而利用该函数计算得到现场脱脂液中的脱脂剂浓度。对酸的加入量、曲线拟合方式和拟合阶数进行探索并得出最佳试验条件。结果将该方法用于中性脱脂剂浓度的快速测定,测定结果相对标准偏差(Relative Standard Deviation,RSD)为0.85%~1.17%,回收率在98.52%~103.34%之间。结论本研究提出的新方法准确可靠、简便快速,克服了传统滴定法和重量法方法的不足,可以有效指导中性脱脂剂的应用,进而提高金属材料的表面质量。展开更多
文摘The macrostructure and properties of the thin walled copper tube prepared by the downward continuous unidirectional solidification （DCUS） method were studied. The result shows that the macrostructure is closely related to the solid-liquid interface profile, which is influenced by the distance between the cooling water location and the solidification front. The mechanical properties of the thin walled copper tube prepared by the DCUS method are near those of the normal cast copper, and it has good relative density, electrical conductivity, and elongation, which are not greatly affected by casting speed. The thin walled copper tube prepared by the DCUS method also has good processing properties that can be taken to further drawing procedures directly without an intermediate process, and obtains good mechanical properties with the total processing rate of 89.8%.
基金Project supported by the Henan Province Science and Technology Tackling Key Problems Project(222102230001)the Henan Province Young Talent Lifting Engineering Project(2021HYTP018)+1 种基金the Central Plain Scholar Workstation Project(224400510025)the National Natural Science Foundation of China(52071133,51904090 and 52071284)。
文摘The effects of Ce addition(310 ppm and 1500 ppm)on the microstructure,texture and properties of ultrahigh-purity copper(99.99999%)were systematically studied using scanning electron microscopy(SEM),transmission electron microscopy(TEM)and electron backscattered diffraction(EBSD)analyses,combined with the microhardness and conductivity tests.Regarding the microstructure of the as-cast and as-extruded samples,the addition of Ce refines the grain size of the ultrahigh-purity copper and the refinement effect of 310Ce alloy is greater than that of 1500Ce alloy.This is due to the stronger compone nt supercooling and the accele rated recrystallization caused by lower Ce co ntent.In addition,Ce can react with Cu to form the Cu-Ce eutectic phases,which are deformable during the hot deformation.Furthermore,the added Ce can weaken the texture,showing a variation of brass recrystallization(BR),rotated cube,copper and S texture components,which depends on the recrystallization,the particle stimulated nucleation(PSN)as well as the stacking fault energy(SFE).Most remarkably,the introduction of Ce enhances the hardness of the ultrahigh-purity copper without obviously reducing its conductivity.The major{111}orientations and the stress distributions are responsible for such a superior conductivity of the Ce-containing alloys.
文摘目的建立定量加酸-非线性拟合测定中性脱脂剂浓度的快速检测方法,解决滴定法和重量法在准确度和检测效率上不足的问题。方法采用脱脂剂原液配制成不同浓度的工作曲线溶液,在其中加入定量的酸后测定其pH值,将测得的pH值与脱脂剂浓度采用非线性拟合得出关系函数,进而利用该函数计算得到现场脱脂液中的脱脂剂浓度。对酸的加入量、曲线拟合方式和拟合阶数进行探索并得出最佳试验条件。结果将该方法用于中性脱脂剂浓度的快速测定,测定结果相对标准偏差(Relative Standard Deviation,RSD)为0.85%~1.17%,回收率在98.52%~103.34%之间。结论本研究提出的新方法准确可靠、简便快速,克服了传统滴定法和重量法方法的不足,可以有效指导中性脱脂剂的应用,进而提高金属材料的表面质量。
