A new type of lightweight AlNiLa medium entropy amorphous alloy composite ribbons(labled as MEAAC ribbons)were prepared by vacuum arc melting technology and high-speed single roller meltspinning method.The microstruct...A new type of lightweight AlNiLa medium entropy amorphous alloy composite ribbons(labled as MEAAC ribbons)were prepared by vacuum arc melting technology and high-speed single roller meltspinning method.The microstructure and thermal stability of MEAAC ribbons were examined using X-ray diffraction,differential scanning calorimeter,and scanning electron microscope.Meanwhile,the hardness and surface roughness of these ribbons were measured by Vickers microhardness tester and atomic force microscope.The potentiodynamic polarization curves and electrochemical impedance spectroscopy(EIS)were applied to investigate the corrosion behavior of these MEAAC ribbons in simulated seawater(3.5wt%NaCl corrosive solution)at room temperature.The results demonstrate that AlNiLa MEAAC ribbons in the as-received state are mainly composed of amorphous phase and intermetallic compounds.The hardness values of all melt-spun ribbons are above 310 HV_(0.1).With the increase of Al content,the linear polarization resistances of four various AlNiLa MEAAC ribbons are negligibly different numerically.It is also found that Al_(45)Ni_(27.5)La_(27.5) MEAAC ribbons have the most positive corrosion potential and the smallest corrosion current density at the same time;hence it may be a kind of potential material for metal surface protection in harsh ocean environment.展开更多
Electrochemical corrosion and oxidation resistances of Zr 60 Ni 21 Al 19 amorphous alloy were studied. The ternary amorphous alloy exhibits greater positive potential than its crystalline counterpart and 0Cr19Ni9Ti st...Electrochemical corrosion and oxidation resistances of Zr 60 Ni 21 Al 19 amorphous alloy were studied. The ternary amorphous alloy exhibits greater positive potential than its crystalline counterpart and 0Cr19Ni9Ti stainless steel. Its weight loss result measured in 2 mol/L HCl solution is in agreement with the potentiodynamic curve. But there is no obvious difference in the oxidation resistances between Zr 60 Ni 21 Al 19 amorphous and its crystalline alloys. They both exhibit high oxidation resistance.展开更多
In this paper, the synthetic effect ofCr, Mo and Y on corrosion resistance was explored, and the YCr/Mo value was employed to evaluate the corrosion resistance. The composition of amorphous alloy was designed by mixin...In this paper, the synthetic effect ofCr, Mo and Y on corrosion resistance was explored, and the YCr/Mo value was employed to evaluate the corrosion resistance. The composition of amorphous alloy was designed by mixing the Fe41Co7Cr15Mo14C15B6Y2 （BMG1） with good glass forming ability （GFA） and Fe50Cr22B23Ni5.4 with a high corrosion resistance at 9：1 ratio. At the same time, the contents of Y, Mo and Cr were fine-tuned. The electrochemical tests demonstrated that the passivation current density decreased with the increase of the yCr/Mo value. The passivation current density of Fe-based amorphous alloy was reduced by about half an order of magnitude. The fitting result showed that the logarithm ofpassivation current density （I） and the YCr/Mo value （X） were logarithmic relationship, and the fitting equation was I=-5.649＋4.904× 1015 e 17.52x. The X-ray photoelectron spectroscopy （XPS） results showed that the yC,/Mo value played a key role in stability of passive films. When the yCr/Mo value Was low, the Cr6＋ ion, Mo6＋ ion were enriched in the initial stage of passivation process, then leading to the increase passivation current density. However, when the YCr/Mo value was high, the low-valence Fe2-, Cr3＋, and Mo4＋ ion were enriched more easily, which result in small passivation current densities and more stable passive films.展开更多
Centimeter-sized Mg65Zn30Ca5 bulk amorphous alloys were fabricated by the spark plasma sintering process from the amorphous powders with a size smaller than 5 la m prepared by ball-milling. The sintered Mg65Zn30Ca5 sa...Centimeter-sized Mg65Zn30Ca5 bulk amorphous alloys were fabricated by the spark plasma sintering process from the amorphous powders with a size smaller than 5 la m prepared by ball-milling. The sintered Mg65Zn30Ca5 samples were in an amorphous state when the spark plasma sintering was performed at a temperature of 383 K under a pressure of 600 MPa. The data of polarization curves presented that the sintered Mg65Zn30Ca5 bulk amorphous alloys exhibited higher corrosion resistance than pure Mg and AZ31B alloy owing to high content of Zn and homogeneous structure. A calcium phosphate compound layer was formed on the sintered Mg65Zn30Ca5 bulk amorphous sample after immersion in Hanks＇ solution, which is effective in improving corrosion resistance and bioactivity. The sintered MgZnCa bulk amorphous alloys with large dimensions broaden the potential application of bulk amorphous alloys in the biomedical fields.展开更多
New Fe(20–35) Ni(20) Cr(20–30) Mo(5–15)(P(0.6) C(0.2) B(0.2))(20) bulk metallic glasses with excellent thermal stability,strength, and corrosion resistance have been developed through the high-entropy alloy design ...New Fe(20–35) Ni(20) Cr(20–30) Mo(5–15)(P(0.6) C(0.2) B(0.2))(20) bulk metallic glasses with excellent thermal stability,strength, and corrosion resistance have been developed through the high-entropy alloy design strategy.The high-entropy bulk metallic glasses(HE-BMGs) possess larger supercooled liquid regions of ~69 K,higher crystallization onset temperatures of ~852 K, larger undercoolings of ~109 K, and more sluggish crystallization process upon heating than the conventional metallic glass benefited from the high mixing entropy effect. The HE-BMGs also exhibit ultrahigh strength of ~3.4 GPa, Vickers hardness of ~1107,and superior corrosion resistance in acids and Na Cl solutions by formation of highly stable Cr-and Moenriched passive films. The new metal-metalloid HE-BMG system and exceptional properties give the alloys good promise for both scientific and engineering applications.展开更多
A dense and well-adhered diamond-like carbon （DLC） coating was prepared on the nickel-titanium （NiTi） alloys by plasma immersion ion implantation and deposition （PIIID）. Potentiodynamic polarization tests indica...A dense and well-adhered diamond-like carbon （DLC） coating was prepared on the nickel-titanium （NiTi） alloys by plasma immersion ion implantation and deposition （PIIID）. Potentiodynamic polarization tests indicated the corrosion resistance of the NiTi alloys was markedly improved by the DLC coating. The Ni ions release of the NiTi alloys was effectively blocked by the DLC coating.展开更多
Mg69Zn27Ca4 alloys with diameters of 1.5, 2 and 3 mm were fabricated using copper mold injection casting method. Microstructural analysis reveals that the alloy with a diameter of 1.5 mm is almost completely composed ...Mg69Zn27Ca4 alloys with diameters of 1.5, 2 and 3 mm were fabricated using copper mold injection casting method. Microstructural analysis reveals that the alloy with a diameter of 1.5 mm is almost completely composed of amorphous phase. However, with the cooling rate decline, a little α-Mg and MgZn dendrites can be found in the amorphous matrix. Based on the microstructural and tensile results, the ductile dendrites are conceived to be highly responsible for the enhanced compressive strain from 1.3% to 3.1% by increasing the sample diameter from 1.5 mm to 3 mm. In addition, the Mg69Zn27Ca4 alloy with 1.5 mm diameter has the best corrosion properties. The current Mg-based alloys show much better corrosion resistance than the traditionally commercial wrought magnesium alloy ZK60 in simulated sea-water.展开更多
There remains growing interest in magnesium(Mg)and its alloys,as they are the lightest structural metallic materials and potential metallic biomaterials.In spite of the greatest historical Mg usage at present,the wide...There remains growing interest in magnesium(Mg)and its alloys,as they are the lightest structural metallic materials and potential metallic biomaterials.In spite of the greatest historical Mg usage at present,the wider use of Mg alloys remains restricted by the poor corrosion resistance.A nano amorphous film,as the composition of Al2O3,had now been deposited on the AZ31 Mg alloy substrate by atomic layer deposition(ALD).Grazing incidence X-ray diffraction(GIXRD),X-ray reflectivity(XRR),X-ray photoelectron spectroscopy(XPS),atomic force microscope(AFM)and scanning electron microscopy(SEM)had been employed to identify the chemical compositions,microstructure and Al2O3/Mg interface of specimens firstly.Then corrosion behavior had been evaluated by neutral salt spray test and electrochemical measurement.The results showed that nano amorphous film made a homogeneous cover on Mg alloy.The film could improve the corrosion resistance of Mg alloy greatly,not only with a positive shift in Ecorr and a decrease in icorr,but also with a more uniform corroded mode.Furthermore,the roughness was found to be an important factor for corrosion resistant,in the way that rougher surface was corroded worse,and greater improvement would be in corrosion resistant after nano amorphous film deposition.展开更多
A new technique of electroplating amorphous Fe-Ni-W alloy deposits was proposed.The structure and morphology o Fe-Ni-W alloy deposit were detected by XRD and SEM.The friction and wear behavior of Fe-Ni-W alloy deposit...A new technique of electroplating amorphous Fe-Ni-W alloy deposits was proposed.The structure and morphology o Fe-Ni-W alloy deposit were detected by XRD and SEM.The friction and wear behavior of Fe-Ni-W alloy deposit were studied and compared with that of chromium deposit.The corrosion properties against 5% sodium chloride,5% sulfuric acid and 5% sodium hydroxide were also discussed.The experimental results indicate that Fe-Ni-W alloy deposits have superior properties against wea than hard chromium deposits under dry sliding condition.Under oil sliding condition,except their better wear resistance,the deposits can protect their counterparts against wear.The deposits plated on brass and AISI 1045 steel show good behavior against corrosion o 5% sodium chloride,5% sulfuric acid and 5% sodium hydroxide.The bath of electroplating amorphous Fe-Ni-W alloy deposits is environmentally friendly and would find widely use in industry.展开更多
The experimental results concerning the effects of Mo on the glass-forming ability(GFA), thermal stability, and mechanical, anticorrosion, and magnetic properties of an(Fe_(71.2)B_(24)Y_(4.8))_(96)Nb_4 bulk metallic g...The experimental results concerning the effects of Mo on the glass-forming ability(GFA), thermal stability, and mechanical, anticorrosion, and magnetic properties of an(Fe_(71.2)B_(24)Y_(4.8))_(96)Nb_4 bulk metallic glass(BMG) were presented. An industrial Fe–B alloy was used as the raw material, and a series of Fe-based BMGs were synthesized. In BMGs with the Mo contents of approximately 1at%–2at%, the cast alloy reached a critical diameter of 6 mm. The hardness and fracture strength also reached their maximum values in this alloy system. However, the anticorrosion and magnetic properties of the BMGs were not substantially improved by the addition of Mo. The low cost, good GFA, high hardness, and high fracture strength of the Fe-based BMGs developed in this work suggest that they are potential candidates for commercial applications.展开更多
基金by the National Key R&D Program of China(No.2018YFC1902400)the National Natural Science Foundation of China(No.51975582)the Natural Science Foundation of Beijing,China(No.2212055)。
文摘A new type of lightweight AlNiLa medium entropy amorphous alloy composite ribbons(labled as MEAAC ribbons)were prepared by vacuum arc melting technology and high-speed single roller meltspinning method.The microstructure and thermal stability of MEAAC ribbons were examined using X-ray diffraction,differential scanning calorimeter,and scanning electron microscope.Meanwhile,the hardness and surface roughness of these ribbons were measured by Vickers microhardness tester and atomic force microscope.The potentiodynamic polarization curves and electrochemical impedance spectroscopy(EIS)were applied to investigate the corrosion behavior of these MEAAC ribbons in simulated seawater(3.5wt%NaCl corrosive solution)at room temperature.The results demonstrate that AlNiLa MEAAC ribbons in the as-received state are mainly composed of amorphous phase and intermetallic compounds.The hardness values of all melt-spun ribbons are above 310 HV_(0.1).With the increase of Al content,the linear polarization resistances of four various AlNiLa MEAAC ribbons are negligibly different numerically.It is also found that Al_(45)Ni_(27.5)La_(27.5) MEAAC ribbons have the most positive corrosion potential and the smallest corrosion current density at the same time;hence it may be a kind of potential material for metal surface protection in harsh ocean environment.
基金financially supported by the National Natural Science Foundation of China (Nos. 51401085 and 51202088)the Shandong Province Higher Educational Science and Technology Program (No. J14LA06)
基金supported by the National Natural Science Foundation of China (Grant Nos. 50731005, 50821001 and 50774006)the National Basic Research Program of China (Grant No. 2010CB731600)
文摘Electrochemical corrosion and oxidation resistances of Zr 60 Ni 21 Al 19 amorphous alloy were studied. The ternary amorphous alloy exhibits greater positive potential than its crystalline counterpart and 0Cr19Ni9Ti stainless steel. Its weight loss result measured in 2 mol/L HCl solution is in agreement with the potentiodynamic curve. But there is no obvious difference in the oxidation resistances between Zr 60 Ni 21 Al 19 amorphous and its crystalline alloys. They both exhibit high oxidation resistance.
基金Project supported by the National Natural Science Foundation of China(51261021)Science and Technology Landing Plan Project of Jiangxi Province(KJLD13056)
文摘In this paper, the synthetic effect ofCr, Mo and Y on corrosion resistance was explored, and the YCr/Mo value was employed to evaluate the corrosion resistance. The composition of amorphous alloy was designed by mixing the Fe41Co7Cr15Mo14C15B6Y2 （BMG1） with good glass forming ability （GFA） and Fe50Cr22B23Ni5.4 with a high corrosion resistance at 9：1 ratio. At the same time, the contents of Y, Mo and Cr were fine-tuned. The electrochemical tests demonstrated that the passivation current density decreased with the increase of the yCr/Mo value. The passivation current density of Fe-based amorphous alloy was reduced by about half an order of magnitude. The fitting result showed that the logarithm ofpassivation current density （I） and the YCr/Mo value （X） were logarithmic relationship, and the fitting equation was I=-5.649＋4.904× 1015 e 17.52x. The X-ray photoelectron spectroscopy （XPS） results showed that the yC,/Mo value played a key role in stability of passive films. When the yCr/Mo value Was low, the Cr6＋ ion, Mo6＋ ion were enriched in the initial stage of passivation process, then leading to the increase passivation current density. However, when the YCr/Mo value was high, the low-valence Fe2-, Cr3＋, and Mo4＋ ion were enriched more easily, which result in small passivation current densities and more stable passive films.
基金financially supported by the Natural Science Foundation of China under Grant No. 51301091the Natural Science Foundation of Jiangsu Province Grant No. BK20151536+1 种基金the Fundamental Research Funds for the Central Universities No. AE16001the Advanced Materials Development and Integration of Novel Structured Metallic and Inorganic Materials from the Ministry of Education, Sport, Culture, Science and Technology, Japan
文摘Centimeter-sized Mg65Zn30Ca5 bulk amorphous alloys were fabricated by the spark plasma sintering process from the amorphous powders with a size smaller than 5 la m prepared by ball-milling. The sintered Mg65Zn30Ca5 samples were in an amorphous state when the spark plasma sintering was performed at a temperature of 383 K under a pressure of 600 MPa. The data of polarization curves presented that the sintered Mg65Zn30Ca5 bulk amorphous alloys exhibited higher corrosion resistance than pure Mg and AZ31B alloy owing to high content of Zn and homogeneous structure. A calcium phosphate compound layer was formed on the sintered Mg65Zn30Ca5 bulk amorphous sample after immersion in Hanks＇ solution, which is effective in improving corrosion resistance and bioactivity. The sintered MgZnCa bulk amorphous alloys with large dimensions broaden the potential application of bulk amorphous alloys in the biomedical fields.
基金financial support of the projects from the National Natural Science Foundation of China(Nos.51871039,51571047,51771039)the Fundamental Research Funds for the Central Universities(DUT17LAB10)。
文摘New Fe(20–35) Ni(20) Cr(20–30) Mo(5–15)(P(0.6) C(0.2) B(0.2))(20) bulk metallic glasses with excellent thermal stability,strength, and corrosion resistance have been developed through the high-entropy alloy design strategy.The high-entropy bulk metallic glasses(HE-BMGs) possess larger supercooled liquid regions of ~69 K,higher crystallization onset temperatures of ~852 K, larger undercoolings of ~109 K, and more sluggish crystallization process upon heating than the conventional metallic glass benefited from the high mixing entropy effect. The HE-BMGs also exhibit ultrahigh strength of ~3.4 GPa, Vickers hardness of ~1107,and superior corrosion resistance in acids and Na Cl solutions by formation of highly stable Cr-and Moenriched passive films. The new metal-metalloid HE-BMG system and exceptional properties give the alloys good promise for both scientific and engineering applications.
文摘A dense and well-adhered diamond-like carbon （DLC） coating was prepared on the nickel-titanium （NiTi） alloys by plasma immersion ion implantation and deposition （PIIID）. Potentiodynamic polarization tests indicated the corrosion resistance of the NiTi alloys was markedly improved by the DLC coating. The Ni ions release of the NiTi alloys was effectively blocked by the DLC coating.
基金Project(NCET-11-0554)supported by the Program for New Century Excellent Talents in UniversityProject(2011BAE22B04)supportedby the National Key Technology R&D Program of ChinaProject(51271206)supported by the National Natural Science Foundation of China
文摘Mg69Zn27Ca4 alloys with diameters of 1.5, 2 and 3 mm were fabricated using copper mold injection casting method. Microstructural analysis reveals that the alloy with a diameter of 1.5 mm is almost completely composed of amorphous phase. However, with the cooling rate decline, a little α-Mg and MgZn dendrites can be found in the amorphous matrix. Based on the microstructural and tensile results, the ductile dendrites are conceived to be highly responsible for the enhanced compressive strain from 1.3% to 3.1% by increasing the sample diameter from 1.5 mm to 3 mm. In addition, the Mg69Zn27Ca4 alloy with 1.5 mm diameter has the best corrosion properties. The current Mg-based alloys show much better corrosion resistance than the traditionally commercial wrought magnesium alloy ZK60 in simulated sea-water.
基金supported by the National Natural Science Foundation of China (Nos. 52071278, 51827801)the National Key Research and Development Program of China (No. 2018YFA0703603)。
基金This work was supported by National Key Research and Development Program(Nos.2016YFB0701201,2016YFB0701203)National Natural Science Foundation of China(Nos.51671101)+3 种基金Domain Foundation of Equipment Advance Research of 13th Five-year Plan(No.61409220118)Natural Science Foundation of JiangXi Province(Nos.20171BCD40003)Key Research and Development Program of JiangXi Province(No GJJ150010)Nanchang University Graduate Innovation Special Fund(No.CX2018038).
文摘There remains growing interest in magnesium(Mg)and its alloys,as they are the lightest structural metallic materials and potential metallic biomaterials.In spite of the greatest historical Mg usage at present,the wider use of Mg alloys remains restricted by the poor corrosion resistance.A nano amorphous film,as the composition of Al2O3,had now been deposited on the AZ31 Mg alloy substrate by atomic layer deposition(ALD).Grazing incidence X-ray diffraction(GIXRD),X-ray reflectivity(XRR),X-ray photoelectron spectroscopy(XPS),atomic force microscope(AFM)and scanning electron microscopy(SEM)had been employed to identify the chemical compositions,microstructure and Al2O3/Mg interface of specimens firstly.Then corrosion behavior had been evaluated by neutral salt spray test and electrochemical measurement.The results showed that nano amorphous film made a homogeneous cover on Mg alloy.The film could improve the corrosion resistance of Mg alloy greatly,not only with a positive shift in Ecorr and a decrease in icorr,but also with a more uniform corroded mode.Furthermore,the roughness was found to be an important factor for corrosion resistant,in the way that rougher surface was corroded worse,and greater improvement would be in corrosion resistant after nano amorphous film deposition.
基金Project(04GK1007) supported by the Science and Technology Office of Hunan Province,China
文摘A new technique of electroplating amorphous Fe-Ni-W alloy deposits was proposed.The structure and morphology o Fe-Ni-W alloy deposit were detected by XRD and SEM.The friction and wear behavior of Fe-Ni-W alloy deposit were studied and compared with that of chromium deposit.The corrosion properties against 5% sodium chloride,5% sulfuric acid and 5% sodium hydroxide were also discussed.The experimental results indicate that Fe-Ni-W alloy deposits have superior properties against wea than hard chromium deposits under dry sliding condition.Under oil sliding condition,except their better wear resistance,the deposits can protect their counterparts against wear.The deposits plated on brass and AISI 1045 steel show good behavior against corrosion o 5% sodium chloride,5% sulfuric acid and 5% sodium hydroxide.The bath of electroplating amorphous Fe-Ni-W alloy deposits is environmentally friendly and would find widely use in industry.
基金financially supported by the National Natural Science Foundation of China (Nos.51322103, 51571079, and 51601050)the National Key Technologies R&D program of China (Nos.2015CB856800 and 2016YFB0300500)the Fundamental Research Funds for the Central Universities of China (Nos.JZ2016HGBZ0772 and JZ2016HGPB0671)
文摘The experimental results concerning the effects of Mo on the glass-forming ability(GFA), thermal stability, and mechanical, anticorrosion, and magnetic properties of an(Fe_(71.2)B_(24)Y_(4.8))_(96)Nb_4 bulk metallic glass(BMG) were presented. An industrial Fe–B alloy was used as the raw material, and a series of Fe-based BMGs were synthesized. In BMGs with the Mo contents of approximately 1at%–2at%, the cast alloy reached a critical diameter of 6 mm. The hardness and fracture strength also reached their maximum values in this alloy system. However, the anticorrosion and magnetic properties of the BMGs were not substantially improved by the addition of Mo. The low cost, good GFA, high hardness, and high fracture strength of the Fe-based BMGs developed in this work suggest that they are potential candidates for commercial applications.
