A Cr/Cr2N/CrN multilayer coating with a thickness of 24.4 μm was deposited by multi-arc ion plating. The coating was systematically characterized by field emission scanning electron microscopy(FESEM), X-ray photoelec...A Cr/Cr2N/CrN multilayer coating with a thickness of 24.4 μm was deposited by multi-arc ion plating. The coating was systematically characterized by field emission scanning electron microscopy(FESEM), X-ray photoelectron spectrometry(XPS), energy dispersive spectroscopy(EDS), X-ray diffraction(XRD) and transmission electron microscopy(TEM). Hardness and adhesion were tested by nanoindentation and scratch tester, respectively. The friction properties were investigated by a reciprocating UMT-3MT ball-on-disk tribometer in air and seawater. The results showed that the multilayer coating consisted of three different layers, with Cr,Cr2N and CrN phases, respectively. Compared with CrN single layer coating, the adhesion of the multilayer coating was improved significantly, the hardness of the multilayer coating was(21±2) GPa. The corrosion resistance of the multilayer coating was also improved in artificial seawater. The friction coefficient of multilayer coating was lower than that of CrN single layer coating both in air and seawater.展开更多
Cr/CrN multilayer coatings with bilayer periods in the range from 1351 to 260 nm were prepared on 304 stainless steel substrates by arc ion plating to study the microstructure and properties of multilayer coatings and...Cr/CrN multilayer coatings with bilayer periods in the range from 1351 to 260 nm were prepared on 304 stainless steel substrates by arc ion plating to study the microstructure and properties of multilayer coatings and stimulate their application.SEM results confirm the clear periodicity of the Cr/CrN multilayer coatings and the clear interface between individual layers.XRD patterns reveal that these multilayer coatings contain Cr,CrN and Cr_2N phases.Because Cr layer is softer than its nitride layer,the hardness decreases with the shortening of the bilayer period(or increasing volume fraction of Cr layer).The Cr/CrN multilayer coating with 862 nm period possesses the highest indentation toughness due to a proper individual Cr and nitride layer thickness.However,for the Cr/CrN multilayer with the bilayer period of 1351 nm,it possesses the lowest toughness due to more nitride phase.The indentation toughness of Cr/CrN multilayer coatings is related with their bilayer period.A coating with a proper individual Cr and nitride layer thickness possesses the highest indentation toughness.展开更多
为了提高航空紧固件涂层的高温工况防护能力,采用磁控溅射技术在钛合金表面分别制备Cr/Cr N交替涂层和Cr/Cr N/Cr Al N涂层,研究氧化时间和氧化温度对涂层高温氧化性能影响。利用SEM、EDS和XRD进行微观形貌和物相成分分析,采用热重法分...为了提高航空紧固件涂层的高温工况防护能力,采用磁控溅射技术在钛合金表面分别制备Cr/Cr N交替涂层和Cr/Cr N/Cr Al N涂层,研究氧化时间和氧化温度对涂层高温氧化性能影响。利用SEM、EDS和XRD进行微观形貌和物相成分分析,采用热重法分析氧化增重量(w)和氧化速率常数(k),使用显微硬度计测试涂层高温氧化后硬度。结果表明:随着氧化时间和氧化温度的增加,涂层硬度均降低,但Cr/Cr N/Cr Al N涂层下降趋势更缓;两种涂层的w和k均上升,其中Cr/Cr N/Cr Al N涂层w和k增幅均低于Cr/Cr N交替涂层,950℃氧化96 h后Cr/Cr N/Cr Al N涂层和Cr/Cr N交替涂层的w值分别为40 mg/cm2和135.7 mg/cm2,其对应的k分别为0.1996和0.4092,说明Cr/Cr N/Cr Al N涂层抗高温氧化性更好。Cr/Cr N/Cr Al N涂层活化能Ea值比Cr/Cr N交替涂层高48.5%,Cr/Cr N/Cr Al N涂层在高温下产生Cr2O3和Al2O3的混合氧化物,结构更致密,Cr/Cr N/Cr Al N涂层抗高温氧化性能高于Cr/Cr N交替涂层。展开更多
目的探究Cr/CrN/Cr/CrAlN多层膜的最佳调制比。方法利用电弧离子镀技术,在TC4钛合金上制备了不同调制比的Cr/CrN/Cr/CrAlN多层膜。利用扫描电子显微镜观察膜层表面和截面形貌;用Image-Pro分析软件对表面的大颗粒进行定量分析;利用X射线...目的探究Cr/CrN/Cr/CrAlN多层膜的最佳调制比。方法利用电弧离子镀技术,在TC4钛合金上制备了不同调制比的Cr/CrN/Cr/CrAlN多层膜。利用扫描电子显微镜观察膜层表面和截面形貌;用Image-Pro分析软件对表面的大颗粒进行定量分析;利用X射线衍射法表征膜层的晶体结构;采用维氏硬度计测量膜层的显微硬度;采用划痕试验仪测量膜层与基体之间的结合力(临界载荷);通过基片弯曲法测量并计算得到膜层的残余应力;利用根据ASTM G76-05标准特制的AS600-喷砂试验机进行了抗冲蚀性能测试;采用三维表面轮廓仪测量冲蚀坑深度。结果膜层表面质量和生长取向与L_(Cr/CrN):L_(Cr/CrAlN)调制比密切相关,随着Cr/CrN比例的增加,膜层表面质量越来越好,择优取向由(111)晶面转为(200)晶面。多层膜的硬度随Cr/CrN比例的增加,呈下降趋势,结合力、残余应力和韧性则随之呈先升后降的趋势,并在L_(Cr/CrN)∶LCr/Cr Al N为1∶2时,达到最佳。多层膜的抗砂粒冲蚀性能变化与力学性能变化一致,在L_(Cr/CrN)∶L_(Cr/CrAlN)为1∶2时达到最佳,其抗冲蚀能力是TC4基材的3倍以上,多层膜呈典型的脆性断裂失效形式。结论在调制比L_(Cr/CrN)∶L_(Cr/CrAlN)=1∶2时,膜层获得最佳的抗冲蚀性能。展开更多
DIN 1.2343 and 1.2367 steels are commonly used as die materials in aluminum extrusion, and single/duplex/multi-coatings enhance their surface properties. The design of an appropriate substrate/coating system is import...DIN 1.2343 and 1.2367 steels are commonly used as die materials in aluminum extrusion, and single/duplex/multi-coatings enhance their surface properties. The design of an appropriate substrate/coating system is important for improving the tribological performance of these steels under service conditions because the load-carrying capacity of the system can be increased by decreasing the plastic deformation of the substrate. In this study, the tribological behavior of CrN-coated Cr–Mo–V steels(DIN 1.2343, 1.2367, and 1.2999 grades) was investigated using different setups and tribological pairs at room and elevated temperatures. The aim of this study was to reveal the wear resistance of a suggested system(1.2999/CrN) not yet studied and to understand both the wear and the failure characteristics of coated systems. The results showed that(i) among the steels studied, the DIN 1.2999 grade steel exhibited the lowest friction coefficient because it had the highest load-carrying capacity as a result of secondary hardening at elevated temperatures;(ii) at room temperature, both abrasive tracks and adhesive layers were observed on the worn surfaces; and(iii) a combination of chemical reactions and progressive oxidation caused aluminum adhesion on the worn surface, and the detachment of droplets and microcracking were the characteristic damage mechanisms at high temperatures.展开更多
基金Project(51475449)supported by the National Natural Science Foundation of China
文摘A Cr/Cr2N/CrN multilayer coating with a thickness of 24.4 μm was deposited by multi-arc ion plating. The coating was systematically characterized by field emission scanning electron microscopy(FESEM), X-ray photoelectron spectrometry(XPS), energy dispersive spectroscopy(EDS), X-ray diffraction(XRD) and transmission electron microscopy(TEM). Hardness and adhesion were tested by nanoindentation and scratch tester, respectively. The friction properties were investigated by a reciprocating UMT-3MT ball-on-disk tribometer in air and seawater. The results showed that the multilayer coating consisted of three different layers, with Cr,Cr2N and CrN phases, respectively. Compared with CrN single layer coating, the adhesion of the multilayer coating was improved significantly, the hardness of the multilayer coating was(21±2) GPa. The corrosion resistance of the multilayer coating was also improved in artificial seawater. The friction coefficient of multilayer coating was lower than that of CrN single layer coating both in air and seawater.
基金Project(51171118)supported by the National Natural Science Foundation of ChinaProject(2012-4)supported by the Liaoning Provincial Key Laboratory of Advanced Materials,Shenyang University,China
文摘Cr/CrN multilayer coatings with bilayer periods in the range from 1351 to 260 nm were prepared on 304 stainless steel substrates by arc ion plating to study the microstructure and properties of multilayer coatings and stimulate their application.SEM results confirm the clear periodicity of the Cr/CrN multilayer coatings and the clear interface between individual layers.XRD patterns reveal that these multilayer coatings contain Cr,CrN and Cr_2N phases.Because Cr layer is softer than its nitride layer,the hardness decreases with the shortening of the bilayer period(or increasing volume fraction of Cr layer).The Cr/CrN multilayer coating with 862 nm period possesses the highest indentation toughness due to a proper individual Cr and nitride layer thickness.However,for the Cr/CrN multilayer with the bilayer period of 1351 nm,it possesses the lowest toughness due to more nitride phase.The indentation toughness of Cr/CrN multilayer coatings is related with their bilayer period.A coating with a proper individual Cr and nitride layer thickness possesses the highest indentation toughness.
文摘为了提高航空紧固件涂层的高温工况防护能力,采用磁控溅射技术在钛合金表面分别制备Cr/Cr N交替涂层和Cr/Cr N/Cr Al N涂层,研究氧化时间和氧化温度对涂层高温氧化性能影响。利用SEM、EDS和XRD进行微观形貌和物相成分分析,采用热重法分析氧化增重量(w)和氧化速率常数(k),使用显微硬度计测试涂层高温氧化后硬度。结果表明:随着氧化时间和氧化温度的增加,涂层硬度均降低,但Cr/Cr N/Cr Al N涂层下降趋势更缓;两种涂层的w和k均上升,其中Cr/Cr N/Cr Al N涂层w和k增幅均低于Cr/Cr N交替涂层,950℃氧化96 h后Cr/Cr N/Cr Al N涂层和Cr/Cr N交替涂层的w值分别为40 mg/cm2和135.7 mg/cm2,其对应的k分别为0.1996和0.4092,说明Cr/Cr N/Cr Al N涂层抗高温氧化性更好。Cr/Cr N/Cr Al N涂层活化能Ea值比Cr/Cr N交替涂层高48.5%,Cr/Cr N/Cr Al N涂层在高温下产生Cr2O3和Al2O3的混合氧化物,结构更致密,Cr/Cr N/Cr Al N涂层抗高温氧化性能高于Cr/Cr N交替涂层。
文摘目的探究Cr/CrN/Cr/CrAlN多层膜的最佳调制比。方法利用电弧离子镀技术,在TC4钛合金上制备了不同调制比的Cr/CrN/Cr/CrAlN多层膜。利用扫描电子显微镜观察膜层表面和截面形貌;用Image-Pro分析软件对表面的大颗粒进行定量分析;利用X射线衍射法表征膜层的晶体结构;采用维氏硬度计测量膜层的显微硬度;采用划痕试验仪测量膜层与基体之间的结合力(临界载荷);通过基片弯曲法测量并计算得到膜层的残余应力;利用根据ASTM G76-05标准特制的AS600-喷砂试验机进行了抗冲蚀性能测试;采用三维表面轮廓仪测量冲蚀坑深度。结果膜层表面质量和生长取向与L_(Cr/CrN):L_(Cr/CrAlN)调制比密切相关,随着Cr/CrN比例的增加,膜层表面质量越来越好,择优取向由(111)晶面转为(200)晶面。多层膜的硬度随Cr/CrN比例的增加,呈下降趋势,结合力、残余应力和韧性则随之呈先升后降的趋势,并在L_(Cr/CrN)∶LCr/Cr Al N为1∶2时,达到最佳。多层膜的抗砂粒冲蚀性能变化与力学性能变化一致,在L_(Cr/CrN)∶L_(Cr/CrAlN)为1∶2时达到最佳,其抗冲蚀能力是TC4基材的3倍以上,多层膜呈典型的脆性断裂失效形式。结论在调制比L_(Cr/CrN)∶L_(Cr/CrAlN)=1∶2时,膜层获得最佳的抗冲蚀性能。
文摘DIN 1.2343 and 1.2367 steels are commonly used as die materials in aluminum extrusion, and single/duplex/multi-coatings enhance their surface properties. The design of an appropriate substrate/coating system is important for improving the tribological performance of these steels under service conditions because the load-carrying capacity of the system can be increased by decreasing the plastic deformation of the substrate. In this study, the tribological behavior of CrN-coated Cr–Mo–V steels(DIN 1.2343, 1.2367, and 1.2999 grades) was investigated using different setups and tribological pairs at room and elevated temperatures. The aim of this study was to reveal the wear resistance of a suggested system(1.2999/CrN) not yet studied and to understand both the wear and the failure characteristics of coated systems. The results showed that(i) among the steels studied, the DIN 1.2999 grade steel exhibited the lowest friction coefficient because it had the highest load-carrying capacity as a result of secondary hardening at elevated temperatures;(ii) at room temperature, both abrasive tracks and adhesive layers were observed on the worn surfaces; and(iii) a combination of chemical reactions and progressive oxidation caused aluminum adhesion on the worn surface, and the detachment of droplets and microcracking were the characteristic damage mechanisms at high temperatures.
