TC4表面激光熔覆AlCoCrFeNiTi0.5高熵合金层的组织与性能

采用激光熔覆技术在TC4(Ti-6Al-4V)钛合金表面制备出了AlCoCrFeNiTi_(0.5)高熵合金熔覆层。运用XRD、OM、SEM、EDS等手段分析了熔覆层的相组成、微观形貌和成分;利用显微硬度仪和多功能摩擦磨损试验机分别检测了熔覆层的硬度和耐磨性能。结果表明:当激光功率P=1500 W,光斑直径D=3 mm,扫描速度V=20 mm/s时,制备出了与基体结合良好,无明显缺陷的高熵合金层。熔覆层主要由面心立方(FCC)结构相、体心立方(BCC)结构相和少量的Laves相组成。熔覆层的平均硬度为699.7 HV0.2,约为基体硬度(298.3 HV0.2)的2.35倍。摩擦磨损试验结果表明熔覆层的耐磨性较基体提高约42倍。     

激光熔覆AlxNbMn2FeMoTi0.5高熵合金涂层的组织与性能

使用激光熔覆技术在Q235钢基体上制备Al_xNbMn₂FeMoTi_0.5高熵合金涂层,期望借此提高干切削技术适用刀具表层的硬度和耐磨性。经过初步筛选之后,主要研究了Al_xNbMn₂FeMoTi_0.5(x=1、1.5、2)高熵合金涂层体系,并采用XRD和3D激光扫描成像等手段分析了不同Al含量的Al_xNbMn₂FeMoTi_0.5合金涂层的晶相结构、显微组织和具体元素分布。结果显示,对于Al_xNbMn₂FeMoTi_0.5高熵合金涂层,随着Al含量的增加,涂层的相结构由单一的BCC相逐渐转变为双相BCC结构,晶粒逐渐细化。当x=2时,Al_xNbMn₂FeMoTi_0.5高熵合金涂层硬度最高,平均为1089.6 HV0.3,大约为基材的5倍,且其具有最优的耐磨损性能。x=1.5时,Al_xNbMn₂FeMoTi_0.5高熵合金涂层的自腐蚀电位最高,自腐蚀电流密度最小,耐腐蚀性最好。     

Y2O3对原位自生TiC增强Ni基涂层组织和性能影响

采用氩弧熔覆的方法,以Ni60A自熔性合金粉末为粘结相,添加Ti粉、C粉和不同含量的稀土氧化物Y₂O₃,在16Mn钢基体上制备出TiC陶瓷颗粒增强金属基熔覆涂层. 运用XRD, SEM等手段对复合涂层的显微组织进行表征和分析,并对熔覆涂层的硬度及耐磨性进行了测试. 结果表明,适量添加Y₂O₃可以使涂层组织中枝晶的方向性减弱、同时细化涂层组织,使涂层组织更加均匀,涂层的硬度和耐磨性有显著提高. 添加2% Y₂O₃熔覆涂层的组织为最细,涂层具有较高的显微硬度和良好的耐磨性能.     

H13钢表面激光熔覆NbC/Ni60复合涂层组织及高温耐磨损性能

目的 研究NbC颗粒的加入量对H13钢表面激光熔覆NbC/Ni60复合涂层的组织、硬度和耐磨性的影响。方法 将Ni60合金粉末与NbC碳化物粉末球磨混合,采用激光熔覆技术,在H13钢基体表面制备不同NbC含量(质量分数分别为0%、10%、20%、30%)增强的NbC/Ni60合金复合涂层。采用电子扫描显微镜(SEM)、X射线衍射仪对复合涂层的微观组织和物相进行分析。借助显微硬度计,研究复合涂层的截面显微硬度分布规律。采用高温摩擦磨损试验机测试复合涂层在真空400℃下的摩擦磨损性能。结果 在激光熔覆NbC/Ni60复合涂层中,物相主要由γ-(Ni, Fe)固溶体、Ni₂Si、CrB、Cr₂₃C₆、NbC组成;熔覆层以胞晶和枝晶为主,NbC含量对复合熔覆层组织及形态具有显著影响,加入少量NbC可使熔覆层组织细化;在NbC的质量分数为20%时,大量弥散的Nb C颗粒在枝晶间呈聚集趋势;在NbC的质量分数为30%时,熔覆层中NbC相呈现块状、花瓣状形貌。NbC/Ni60复合涂层的硬度显著高于H13钢基体,随着NbC含量的增加,N...     

激光熔覆Ni-WC/Cr3C2涂层组织及性能

采用激光技术在45钢表面熔覆Ni-WC/Cr₃C₂涂层,采用SEM,XRD等手段进行熔覆层的显微组织、相组成及成分分析,并测试熔覆层的耐蚀性和耐磨性能.结果表明,Ni-WC/Cr₃C₂熔覆层底部生成方向性较强的胞状树枝晶,中上部组织为细小的树枝晶.涂层主要是由γ-(Fe, Ni),M₂₃C₆型碳化物以及未熔的WC颗粒组成.细晶强化、合金元素固溶强化以及碳化物强化的共同作用,使熔覆层的显微硬度提高至711HV0.1.熔覆层耐蚀性明显改善,腐蚀电流密度约为45钢的1/4.随着摩擦速度的增大,激光熔覆Ni-WC/Cr₃C₂涂层和45钢磨损量增加,且熔覆层的磨损量低于45钢,表明其耐磨性能明显提高.     

激光熔覆AlCrCoFeNiMoTi0.75Si0.25高熵合金涂层刀具的性能

利用激光熔覆技术制备了AlCrCoFeNiMoTi0.75Si0.25高熵合金涂层刀具,研究了激光快速凝固和经过1 000℃退火处理的AlCrCoFeNiMoTi0.75Si0.25高熵合金涂层微观组织和硬度、摩擦磨损性能,并比较了普通高速钢及高熵合金涂层刀具的切削加工性能。结果表明:激光熔覆AlCrCoFeNiMoTi0.75Si0.25高熵合金涂层的主要相结构为bcc相,涂层具有较好的高温稳定性。激光熔覆高熵合金涂层刀具表面硬度高,摩擦因数小,断屑效果好,被加工材料表面光洁度高。     

纯铜表面氩弧熔覆TiB2/Ni复合涂层组织及耐磨性能

通过氩弧熔覆技术在纯铜表面制备TiB₂增强 Ni 基复合涂层,以改善其耐磨性能. 将钛粉、硼粉和镍粉在球磨机中充分混合,采用氩弧熔覆技术将纯铜表面预置粉末熔化制备出陶瓷颗粒增强镍基熔覆层. 采用X射线衍射仪、扫描电子显微镜、透射电子显微镜分析涂层的物相及涂层中陶瓷颗粒相的组成、分布及结构,利用显微硬度仪和摩擦磨损试验机测试涂层的显微硬度和耐磨性能. 结果表明,熔覆层物相主要包括γ(Ni, Cu)和TiB₂;陶瓷颗粒增强相弥散分布于熔覆层中,其中颗粒相TiB₂以六边形存在,熔覆层内部与基体界面处均无缺陷产生;熔覆涂层具有较高的显微硬度,当(Ti+B)质量分数为10%时,涂层显微硬度高达781.3 HV,与纯铜基体对比,熔覆层显微硬度提高约11.7倍;在相同磨损条件下,随(Ti+B)质量分数的增加,熔覆涂层的摩擦系数及磨损失重先减小后增大;氩弧熔覆原位自生TiB₂陶瓷颗粒增强镍基熔覆层可显著提高纯铜表面的耐磨性能.     

氩弧熔覆AlxCoCrFeCuNi高熵合金涂层组织与耐磨性

目的 利用氩弧熔覆技术在45钢表面制备出AlCrFeCoCuNi高熵合金涂层，改善其耐磨性能。方法 采用机械球磨方式将Al、Cr、Fe、Co、Cu、Ni粉均匀混合，预涂敷在45钢表面，利用氩弧熔覆技术制备出不同Al物质的量之比的高熵合金涂层。采用X射线衍射仪、扫描电子显微镜及能谱分析仪分析涂层的物相及显微组织，利用显微硬度仪测试涂层表面及截面的显微硬度。采用摩擦磨损试验机测试涂层的摩擦系数及磨损率，分析涂层的耐磨性能。结果 Al_xCrFeCoCuNi高熵合金涂层物相主要包括面心立方(FCC)相和体心立方(BCC)相，当Al物质的量之比小于0.5时，涂层由FCC相构成；当Al物质的量之比为1.0～2.0时，涂层由BCC+FCC相构成；当Al物质的量之比达到2.5时，涂层仅存在BCC相。Al_xCrFeCoCuNi高熵合金涂层组织由等轴晶、柱状晶及白色的晶界构成，且较为致密。Al物质的量之比的增加使得涂层的显微硬度提升，当Al物质的量之比为2.5时，涂层最高硬度为710 HV0.5。在相同磨损条件下，Al_xCrFeCoCuNi...     

钛合金表面激光熔覆AlCoCrFeMoVTi高熵合金涂层的摩擦磨损和高温抗氧化性能

为提高钛合金的摩擦磨损和高温抗氧化性能,采用激光熔覆技术在Ti6Al4V(TC4)钛合金表面制备了近等原子比的AlCoCrFeMoVTi高熵合金(HEA)涂层。借助X射线衍射(XRD)、扫描电镜(SEM)、能谱仪(EDS)等分析了涂层的物相组成和显微组织;利用HDX-1000维氏硬度仪测试了熔覆层显微硬度;通过UMT-3摩擦磨损试验机和GSL-1400X型管式电阻炉分别测试了HEA涂层的摩擦磨损性能和高温抗氧化性能。结果表明,HEA涂层主要由面心立方(fcc)、体心立方(bcc)二元共晶相组成;HEA涂层最高显微硬度HV0.2为10 990 MPa,是基体TC4的3.29倍;涂层摩擦系数为0.31,磨损体积为1.79×10~(-4)mm~3,分别为基体的59.62%和12.01%;在800℃恒温下氧化50h后,HEA涂层的氧化增重为1.49 mg,仅为基体的16.37%。激光熔覆高熵合金AlCoCrFeMoVTi涂层能显著改善Ti6Al4V钛合金的摩擦磨损和高温抗氧化性能。     

激光熔覆原位自生TiC-CrxSy/Ni基复合涂层的组织与性能

采用激光熔覆技术在Ti6Al4V合金表面制备出原位自生TiC-Cr_xS_y/Ni基复合涂层,利用X射线衍射仪（XRD）、扫描电子显微镜（SEM）和能谱仪（EDS）分析了不同Ni包MoS₂含量对涂层物相组成、显微组织的影响,并测试了涂层的硬度及摩擦磨损性能。结果表明,在激光熔覆过程中Ni包MoS₂发生了分解反应,分解后的S大部分生成了新的润滑相Cr_xS_y、TiS。随着Ni包MoS₂含量的增加,复合涂层凝固组织逐渐细化,树枝相、多边块状相逐渐减少,球状相、条状相逐渐增多。由于上述组织的变化,涂层的显微硬度先增大后减小,摩擦因数逐渐减小。当Ni包MoS₂含量为40%时,涂层的显微硬度为1048 HV0.3,摩擦因数为0.19,磨损机理表现为轻微犁削,此时涂层的耐磨性能最优。     

Amorphization of Fe38Ni30Si16B14V2 surface layers by laser cladding

Fe38Ni30Si16B14V2 amorphous composite coatings were fabricated by laser cladding on AISI 1045 steel in order to increase the wear resistance. The phase and microstructure of the coatings were analyzed by X-ray diffractometry and transmission electron microscopy. The wear properties of the coatings were also investigated by means of sliding wear test. The results show that the coating consists of amorphous phase in majority and nanocrystalline phase in minority. The amorphous coatings can be obtained while the scanning speed is 3 500 mm/min and the laser power is 4.8 kW. With increase of the laser power, the amorphous phase in the coating increases when it is lower than 4.8 kW. A gradient distribution of the microhardness ranges from Hv0.2 1 208 to Hv0.2 891 in the coating from top surface of the coating to the substrate. The amorphous coating is found to possess better property of wear than AISI 1045 steel substrate.     

基体材料对Cr/CrN多层涂层在海水环境中磨蚀性能的影响

目的 讨论海水环境下不同基体材料对Cr/CrN交替的多层复合涂层磨蚀性能的影响,为海水环境下耐磨蚀材料基体的选择和应用提供参考。方法 采用多弧离子镀技术在316L不锈钢和TC4钛合金基体上沉积Cr/CrN多层复合涂层,通过XRD、SEM等技术对涂层材料的微观结构进行表征,通过硬度测试、结合力测试、电化学分析、摩擦磨损试验等技术对涂层材料的力学性能、电化学性能以及摩擦学性能进行分析,比较不同基体对Cr/CrN多层涂层在海水环境中磨蚀性能的影响。结果 以TC4钛合金为基体的Cr/CrN多层涂层的硬度为1727.2HV0.3,虽略小于以316L不锈钢为基体的涂层硬度（2241.5HV0.3）,但其在膜-基结合力、海水环境下电化学性能和摩擦学性能等方面均优于以316L不锈钢为基体的涂层。结合力测试中,以TC4为基体的多层涂层初始裂纹出现在31 N,扩展裂纹出现在42 N,大于316L基体涂层的22 N和35 N。电化学测试中TC4基体涂层的腐蚀电位为?0.20 V,大于316L基体涂层的腐蚀电位（?0.21 V）。海水环境下TC4基体涂层的平均摩擦系数和磨损率分别为0.35和2.9950×10?5 mm3/(N?m),均小于316 L基体涂层的平均摩擦系数（0.36）和磨损率（4.9895×10?5 mm3/(N?m)）。结论 TC4钛合金更适合作为海水环境用Cr/CrN多层涂层耐磨蚀材料的基体材料。     

等离子喷涂硫化亚铁润滑层的摩擦学性能

利用等离子喷涂在 45钢表面制备了三种厚度不同的硫化亚铁固体润滑层。在QP 1 0 0摩擦磨损试验机上测定了硫化亚铁喷涂层在油润滑条件下的摩擦学性能。利用XRD分析了硫化亚铁喷涂层的相结构 ,用SEM观察了喷涂层的磨面形貌。结果表明 ,硫化亚铁喷涂层的减摩、耐磨、抗擦伤性能明显优于 45钢原始表面。     

Optimum Me-DLC coatings and hard coatings for tribological performance

In this study, hard coatings (TiN, TiCN, CrN, and CrCN) and Me-DLC coatings (Ti _x%-C:H and Cr _x%-C:H) were deposited on tungsten carbide (WC) substrate by multiarc physical vapor deposition (MAPVD) and unbalanced magnetron (UBM) sputtering, respectively. Counterbodies of the AISI 1045 steel cylinder and the AA7075T651 aluminum cylinder were used in the cylinder-on-disk, line-contact wear mode under dry condition; a counterbody of the AISI 52100 steel ball was used in the ball-on-disk, point-contact wear mode, under both dry and lubricated conditions. All wear tests were conducted with a reciprocating machine. After the tests, the most suitable coating for various counterbodies and test environments was selected. For the coating/1045 steel cylinder, the Ti_10%-C:H coating possesses excellent tribological characteristics. For the coating/7075T651 aluminum cylinder, hard coatings display excellent wear resistance. For the coating/steel ball, CrCN and CrN coatings display very little wear under both dry and lubricated conditions. On TiN and TiCN coatings, special wear mechanisms of material transfer, adhesion wear, and fatigue fracture occurred during initial tests under kerosene lubrication.     

WC-(W,Cr)_2C-Ni/Ag复合涂层的制备及摩擦学性能

针对众多运动部件存在严重的摩擦磨损问题,使用大气等离子喷涂(APS)设备在1Cr18Ni9Ti不锈钢金属基材上喷涂制备WC-(W,Cr)2C-Ni和WC-(W,Cr)2C-Ni/Ag两种防护涂层,使用CSM摩擦磨损试验机考察两种涂层在室温下与Si3N4球配副时的滑动摩擦磨损性能。结果表明:Ag相的添加可明显降低涂层在干摩擦条件下的摩擦因数,并能减轻涂层的磨损程度;APS制备的WC-(W,Cr)2C-Ni/Ag复合涂层不仅具有优良的自润滑性能,而且具有极佳的耐磨性能,有望作为一种新型耐磨自润滑涂层材料。     

不同掺杂设计对类金刚石涂层海水环境摩擦学性能的影响

采用UDP650型闭合场非平衡磁控溅射系统在硅片及316不锈钢基底表面制备了不同掺杂设计的类金刚石涂层(DLC、Cr/DLC和WC/DLC),通过SEM、Raman、硬度仪和划痕仪研究了涂层的结构及力学性能,利用多功能摩擦试验机考察了涂层在大气及海水环境下的摩擦学性能。结果表明,Cr或WC掺杂能显著促进DLC涂层的石墨化,同时提高涂层的结合力及韧性。在摩擦磨损试验中,由于海水的润滑作用,3种涂层在海水环境下的摩擦因数及磨损率均低于大气环境。同时,WC/DLC在3种涂层中表现出最佳的摩擦学性能,这取决于其高的石墨化程度,良好的结合力及优异的韧性。     

40Cr钢表面渗氮及制备CrN涂层在重载低速下的摩擦学性能

目的提高40Cr齿轮在重载低速下的摩擦学性能。方法采用离子渗氮和电弧离子蒸发镀(AED)技术在40Cr钢基体上制备了渗氮层和Cr N涂层。用X射线衍射仪、扫描电子显微镜、能谱仪和往复式摩擦磨损试验机,研究了经两种表面处理后40Cr钢的物相组成、形貌和摩擦学性能。结果渗氮样品表面化合物层厚度约10μm,硬度约为558HV。Cr N涂层表面厚度约为4μm,涂层硬度约为1341HV。在60 N载荷的条件下,渗氮处理后40Cr钢的磨损率为104.17×10-6 mm3/(N·m),其磨损机理主要为轻微的粘着磨损和磨粒磨损;制备Cr N涂层后40Cr钢的磨损率为17.36×10-6 mm3/(N·m),其磨损机理主要为轻微的磨粒磨损。结论在20~60 N法向载荷下,制备Cr N涂层后,40Cr钢均表现出最优异的耐磨减摩性能。     

Studies on the Sliding Wear Performance of Plasma Spray Ni-20Cr and Ni3Al Coatings

Two metallic powders namely Ni-20Cr and Ni₃Al were coated on AISI 309 SS steel by shrouded plasma spray process. The wear behavior of the bare, Ni-20Cr and Ni₃Al-coated AISI 309 SS steel was investigated according to ASTM Standard G99-03 on a Pin-on-Disc Wear Test Rig. The wear tests were carried out at normal loads of 30 and 50 N with a sliding velocity of 1 m/s. Cumulative wear rate and coefficient of friction (μ) were calculated for all the cases. The worn-out surfaces were then examined by scanning electron microscopy analysis. Both the as-sprayed coatings exhibited typical splat morphology. The XRD analysis indicated the formation of Ni phase for the Ni-20Cr coating and Ni₃Al phase for the Ni₃Al coating. It has been concluded that the plasma-sprayed Ni-20Cr and Ni₃Al coatings can be useful to reduce the wear rate of AISI 309 SS steel. The coatings were found to be adherent to the substrate steel during the wear tests. The plasma-sprayed Ni₃Al coating has been recommended as a better choice to reduce the wear of AISI 309 SS steel, in comparison with the Ni-20Cr coating.     

Effect of number of layers on erosion,corrosion, and wear resistance of multilayer Cr–N/Cr–Al–N coatings on AISI 630 stainless steel

In the present study, multilayered Cr–N/Cr–Al–N coatings were prepared by cathodic arc physical vapor deposition (PVD) with different numbers of layers and the same total thickness on AISI 630 steel in an attempt to improve the wear and erosion–corrosion resistance. Structural analysis of the coatings was performed by field scanning electron microscopy, X-ray diffraction (XRD), and energy-dispersive spectroscopy. Depth profiles and roughness parameters of worn surfaces were calculated after erosion and wear tests. XRD indicated that nitride compounds were formed in multilayer coatings by PVD. The Cr–N/Cr–Al–N coating exhibited superior corrosion resistance compared with AISI 630 substrate. The erosion–corrosion results revealed that the smoothest wear track with the minimum erosion rate and wear depth was obtained for five- and seven-layered coatings. The failure mechanism of the bare substrate was influenced by plastic deformation via cutting and plowing, while the failure mechanism for coated samples was chipping and delamination. According to the wear results, the multilayer coatings showed a lower friction coefficient and better surface morphology that demonstrated their high ability for wear protection.     

激光熔覆NiCrBSi/Ag复合涂层 结构及空间摩擦学性能

目的 提高钛及钛合金的空间摩擦学性能,拓展钛及钛合金在空间技术领域的应用范围。方法 用激光熔覆技术在纯钛基材表面制备了NiCrBSi/Ag复合涂层。用X-射线衍射仪、扫描电镜和高分辨透射电镜分析涂层的物相组成、显微组织结构和晶体结构。用空间摩擦学实验系统对NiCrBSi/Ag复合涂层在真空、原子氧和紫外辐照三种模拟空间环境以及大气环境下的摩擦学性能进行系统的研究。采用扫描电镜和能量色散光谱仪对摩擦测试后NiCrBSi/Ag复合涂层的磨痕形貌和对偶不锈钢钢球的磨痕形貌及元素面分布进行分析。深入探讨NiCrBSi/Ag复合涂层在三种模拟空间环境及大气环境下的磨损机理。结果 在纯钛基材表面通过激光熔覆制备的NiCrBSi/Ag复合涂层主要物相组成为NiTi、Ni3Ti、Cr2Ni3、Cr3Si、TiB2、Cr-Ni-Ti-Fe、Ag相,显微结构主要为等轴晶和枝状晶组织。复合涂层具有较高的显微硬度,涂层截面平均显微硬度约为830HV0.2,约是钛基材硬度的4.4倍。复合涂层在真空、原子氧和紫外辐照模拟空间环境下的摩擦系数和磨损率均小于大气环境下的值。在三种模拟空间环境下,相对于纯钛基材,复合涂层的磨损率约小2个数量级。复合涂层在真空、原子氧和紫外辐照模拟空间环境下的磨损机理为粘着磨损和磨粒磨损,在大气环境下的磨损机理主要为磨粒磨损。结论 NiCrBSi/Ag复合涂层可以显著提高纯钛基材在真空、原子氧和紫外辐照三种模拟空间环境以及大气环境下的摩擦学性能。