The effect of IB element additions [Ag] on the corrosion behavior of AlZn alloy has been investigated. The potentiodynamic polarization curves revealed that the corrosion behavior of SSAl, SSZn and AgZn3 phases was si...The effect of IB element additions [Ag] on the corrosion behavior of AlZn alloy has been investigated. The potentiodynamic polarization curves revealed that the corrosion behavior of SSAl, SSZn and AgZn3 phases was significantly influenced by IB element content. The electrochemical investigations showed that the corrosion rate increased with the IB-element additions. Furthermore, it was also evidenced the formation of a passive layer for the highest Ag content alloys;the passivity of this layer could be broken due to the presence of the intermetallic compound (IMCs) AgZn3.展开更多
对铝合金表面非平衡磁控溅射沉积类石墨镀层,采用极化曲线测试和质量损失方法,分析了镀层的耐蚀性;利用扫描电子显微镜对镀层腐蚀前后的微观形貌进行了观察。结果表明,铝合金表面磁控溅射类石墨镀层由铬打底层和碳工作层组成。镀层组织...对铝合金表面非平衡磁控溅射沉积类石墨镀层,采用极化曲线测试和质量损失方法,分析了镀层的耐蚀性;利用扫描电子显微镜对镀层腐蚀前后的微观形貌进行了观察。结果表明,铝合金表面磁控溅射类石墨镀层由铬打底层和碳工作层组成。镀层组织细小,均匀致密,类石墨镀层可以提高铝合金的耐蚀性。随基体负偏压增大,铝合金试样的耐蚀性增加,当基体为-120 V偏压时,铝合金基体的自腐蚀电位由-0.452 V提高到-0.372 V,腐蚀电流由10.62 m A减小到3.67 m A。在Na Cl溶液中进行浸泡试验后,类石墨镀层仅发生了部分点蚀,可很好地保护铝合金基体。展开更多
Al-6Zn-2.5Mg-1.8Cu alloy ingots were prepared by squeeze casting under different specific pressures,and the fresh ingot with best mechanical properties was solid hot extruded.With the increase of the specific pressure...Al-6Zn-2.5Mg-1.8Cu alloy ingots were prepared by squeeze casting under different specific pressures,and the fresh ingot with best mechanical properties was solid hot extruded.With the increase of the specific pressure from 0 to 250 MPa,the dendrites became round and small.Because the applied pressure increased the solid solubility of alloying elements,the number of MgZn2 phases decreased.When the specific pressure increased from 250 MPa to 350 MPa,the grain size increased.After solid hot extrusion,the a（Al） grains were refined obviously and the MgZn2 phases were uniformly dispersed in the microstructure.After solid hot extrusion,the ultimate tensile strength was 605.67 MPa and the elongation was 8.1%,which were improved about 32.22%and15.71%,respectively,compared with those of the metal mold casting alloy.The fracture modes of the billet prepared by the metal mold casting and by squeeze casting were intergranular and quasi-cleavage fractures,respectively,whereas,that of the solid hot extrusion was mainly dimple fracture.The refined crystalline strengthening was the main reason to improve the strength and elongation of alloy.展开更多
This study investigates the eff ect of solution treatment(at 470°C for 0–48 h)on the microstructural evolution,tensile properties,and impact properties of an Al–5.0Mg–3.0Zn–1.0Cu(wt%)alloy prepared by permane...This study investigates the eff ect of solution treatment(at 470°C for 0–48 h)on the microstructural evolution,tensile properties,and impact properties of an Al–5.0Mg–3.0Zn–1.0Cu(wt%)alloy prepared by permanent gravity casting.The results show that the as-cast microstructure consists ofα-Al dendrites and a network-like pattern of T-Mg32(AlZnCu)49 phases.Most of the T-phases were dissolved within 24 h at 470℃;and a further prolonging of solution time resulted in a rapid growth ofα-Al grains.No transformation from the T-phase to the S-Al2CuMg phase was discovered in this alloy.Both the tensile properties and impact toughness increased quickly,reached a maximum peak value,and decreased gradually as the solution treatment proceeded.The impact toughness is more closely related to the elongation,and the relationship between impact toughness and elongation appears to obey an equation:IT=8.43 EL-3.46.After optimal solution treatment at 470℃for 24 h,this alloy exhibits excellent mechanical properties with the ultimate tensile strength,yield strength,elongation and impact toughness being 431.6 MPa,270.1 MPa,19.4%and 154.7 kJ/m^(2),which are comparable to that of a wrought Al–6.0 Mg–0.7 Mn alloy(5E06,a 5 xxx aluminum alloy).Due to its excellent comprehensive combination of mechanical properties,this cast alloy has high potential for use in components which require medium strength,high ductility and high toughness.展开更多
Al-Mg-Zn-Er-Zr alloy was compressed in temperature range from 300 to 500℃to investigate the microstructure evolution.Molecular dynamics simulations were used to study the mechanical behavior and dislocation evolution...Al-Mg-Zn-Er-Zr alloy was compressed in temperature range from 300 to 500℃to investigate the microstructure evolution.Molecular dynamics simulations were used to study the mechanical behavior and dislocation evolution.The results showed that mobile dislocations are widely distributed in alloys and make important contributions to coordinate compressive deformation.The sessile dislocations hinder the deformation,and the content is about 1/20 of that of mobile dislocations.Continuous dynamic recrystallization(CDRX)is considered to be the main recrystallization mechanism.The accumulation of dislocations can provide element diffusion channels and driving force forτ(Mg_(32)[Al,Zn]_(49))phase precipitation,resulting in the forced precipitation of discontinuousτphase to replace the continuousβphase(Al_(3)Mg_(2)),which reduces the corrosion potential,resulting in increased corrosion resistance.展开更多
文摘The effect of IB element additions [Ag] on the corrosion behavior of AlZn alloy has been investigated. The potentiodynamic polarization curves revealed that the corrosion behavior of SSAl, SSZn and AgZn3 phases was significantly influenced by IB element content. The electrochemical investigations showed that the corrosion rate increased with the IB-element additions. Furthermore, it was also evidenced the formation of a passive layer for the highest Ag content alloys;the passivity of this layer could be broken due to the presence of the intermetallic compound (IMCs) AgZn3.
文摘对铝合金表面非平衡磁控溅射沉积类石墨镀层,采用极化曲线测试和质量损失方法,分析了镀层的耐蚀性;利用扫描电子显微镜对镀层腐蚀前后的微观形貌进行了观察。结果表明,铝合金表面磁控溅射类石墨镀层由铬打底层和碳工作层组成。镀层组织细小,均匀致密,类石墨镀层可以提高铝合金的耐蚀性。随基体负偏压增大,铝合金试样的耐蚀性增加,当基体为-120 V偏压时,铝合金基体的自腐蚀电位由-0.452 V提高到-0.372 V,腐蚀电流由10.62 m A减小到3.67 m A。在Na Cl溶液中进行浸泡试验后,类石墨镀层仅发生了部分点蚀,可很好地保护铝合金基体。
基金Project(50971092)supported by the National Natural Science of Foundation of ChinaProject(201202166)supported by the Natural Science Foundation of Education Department of Liaoning Province,China
文摘Al-6Zn-2.5Mg-1.8Cu alloy ingots were prepared by squeeze casting under different specific pressures,and the fresh ingot with best mechanical properties was solid hot extruded.With the increase of the specific pressure from 0 to 250 MPa,the dendrites became round and small.Because the applied pressure increased the solid solubility of alloying elements,the number of MgZn2 phases decreased.When the specific pressure increased from 250 MPa to 350 MPa,the grain size increased.After solid hot extrusion,the a（Al） grains were refined obviously and the MgZn2 phases were uniformly dispersed in the microstructure.After solid hot extrusion,the ultimate tensile strength was 605.67 MPa and the elongation was 8.1%,which were improved about 32.22%and15.71%,respectively,compared with those of the metal mold casting alloy.The fracture modes of the billet prepared by the metal mold casting and by squeeze casting were intergranular and quasi-cleavage fractures,respectively,whereas,that of the solid hot extrusion was mainly dimple fracture.The refined crystalline strengthening was the main reason to improve the strength and elongation of alloy.
基金the United Fund of National Natural Science Foundation of China and Yunnan Province(No.U1902220)the National Natural Science Foundation of China(No.51674166)。
文摘This study investigates the eff ect of solution treatment(at 470°C for 0–48 h)on the microstructural evolution,tensile properties,and impact properties of an Al–5.0Mg–3.0Zn–1.0Cu(wt%)alloy prepared by permanent gravity casting.The results show that the as-cast microstructure consists ofα-Al dendrites and a network-like pattern of T-Mg32(AlZnCu)49 phases.Most of the T-phases were dissolved within 24 h at 470℃;and a further prolonging of solution time resulted in a rapid growth ofα-Al grains.No transformation from the T-phase to the S-Al2CuMg phase was discovered in this alloy.Both the tensile properties and impact toughness increased quickly,reached a maximum peak value,and decreased gradually as the solution treatment proceeded.The impact toughness is more closely related to the elongation,and the relationship between impact toughness and elongation appears to obey an equation:IT=8.43 EL-3.46.After optimal solution treatment at 470℃for 24 h,this alloy exhibits excellent mechanical properties with the ultimate tensile strength,yield strength,elongation and impact toughness being 431.6 MPa,270.1 MPa,19.4%and 154.7 kJ/m^(2),which are comparable to that of a wrought Al–6.0 Mg–0.7 Mn alloy(5E06,a 5 xxx aluminum alloy).Due to its excellent comprehensive combination of mechanical properties,this cast alloy has high potential for use in components which require medium strength,high ductility and high toughness.
基金financially supported by the National Key Research and Development Program of China(No.2021YFB 3704202)the General Program of Science and Technology Development Project of Beijing Municipal Education Commission(No.KM 202110005010)the Innovative Research Group Project of the National Natural Science Fund(No.51621003)。
文摘Al-Mg-Zn-Er-Zr alloy was compressed in temperature range from 300 to 500℃to investigate the microstructure evolution.Molecular dynamics simulations were used to study the mechanical behavior and dislocation evolution.The results showed that mobile dislocations are widely distributed in alloys and make important contributions to coordinate compressive deformation.The sessile dislocations hinder the deformation,and the content is about 1/20 of that of mobile dislocations.Continuous dynamic recrystallization(CDRX)is considered to be the main recrystallization mechanism.The accumulation of dislocations can provide element diffusion channels and driving force forτ(Mg_(32)[Al,Zn]_(49))phase precipitation,resulting in the forced precipitation of discontinuousτphase to replace the continuousβphase(Al_(3)Mg_(2)),which reduces the corrosion potential,resulting in increased corrosion resistance.
