热处理对高速电弧喷涂Fe基非晶涂层抗空蚀性能的影响

利用高速电弧喷涂技术在Q235钢表面制备了FeNiCrBSiNbW非晶涂层,随后对其进行了不同温度的热处理,采用X射线衍射仪、扫描电镜、能谱仪、差示扫描量热仪、电子万能试验机、显微硬度计、纳米压痕仪和磁致伸缩空蚀仪等研究了不同温度热处理对涂层的组织结构、力学性能和空蚀行为的影响.结果 表明:随着热处理温度的升高,FeNiCrBSiNbW非晶涂层的非晶相含量、孔隙率、结合强度与断裂韧性逐渐降低,硬度与弹性模量逐渐增大,涂层在蒸馏水中的抗空蚀性能逐渐下降;喷涂态涂层的空蚀失效形式主要是片层状的脆性剥落.     

热喷涂FeCrBSiNbW涂层结构演变及空蚀性能

利用高速电弧喷涂技术成功制备了FeCrBSiNbW非晶纳米晶涂层,系统研究了不同热处理温度下,高速电弧喷涂FeCrBSiNbW非晶纳米晶涂层组织结构的演变规律。采用扫描电镜(SEM)、能谱分析仪(EDS)和X射线衍射仪(XRD)等对涂层的组织结构进行了表征,在磁致伸缩汽蚀仪上采用失重分析法对不同热处理工艺下涂层的抗空蚀性能进行了研究,探讨涂层的空蚀破坏机理。结果表明：随着热处理温度的升高,涂层中非晶含量逐渐降低,当热处理温度高于550 ℃时,涂层中由单一的α(Fe,Cr)相转变为α(Fe,Cr)+ Fe3B相。涂层中α (Fe,Cr)晶粒尺寸随着热处理温度的升高逐渐增大,显微硬度也随之升高。空蚀实验结果表明,电弧喷涂FeCrBSiNbW非晶纳米晶涂层的抗空蚀性能随着非晶含量的降低而下降, 喷涂态涂层累积空蚀失重量最小,650 ℃热处理后涂层经180 min空蚀试验累积失重量最大,达到56.8 mg;涂层的失效模式主要为脆性剥落机制。     

FeNiCrBSiNbW非晶涂层组织及空蚀性能

采用自动化高速电弧喷涂技术在45钢基体表面上制备了高非晶含量的FeNiCrBSiNbW涂层和1Cr18Ni9Ti不锈钢涂层。采用扫描电镜、能谱分析仪和X射线衍射仪等对涂层的组织结构进行表征;在磁致伸缩汽蚀仪上采用失重分析法对非晶涂层的空蚀性能进行试验研究,并用扫描电镜观察涂层的表面及截面的空蚀形貌,探讨非晶涂层的空蚀破坏机理。结果表明:FeNiCrBSiNbW涂层的组织均匀,结构致密,起始晶化温度为528℃,平均孔隙率为3.5%,硬度为967 HV。FeNiCrBSiNbW非晶涂层的抗空蚀性能明显优于1Cr18Ni9Ti不锈钢涂层。     

Fe基非晶纳米晶涂层在油润滑条件下的耐磨损性能

采用自动化高速电弧喷涂技术在AZ91镁合金基体上制备了厚度约为300μm的Fe基非晶纳米晶涂层。研究了Fe基非晶纳米晶涂层在油润滑条件下,不同速度(180r/min、300r/min、600r/min、900r/min、1200r/min)、载荷(2.5N、5N、10N、20N、30N)对涂层的摩擦磨损行为。采用扫描电镜、能谱分析仪、X射线衍射仪和透射电镜对涂层的组织结构进行了表征,利用纳米压痕仪对涂层的力学性能进行了分析。试验结果表明:Fe基非晶纳米晶涂层组织均匀、结构致密,氧化物含量和孔隙率低,主要由非晶相和纳米晶相组成;涂层具有较高的硬度(12.03GPa)和弹性模量(197.1GPa)。在载荷为30N、速度为300r/min、磨损时间为900s条件下,其相对耐磨性是3Cr13涂层的3倍。Fe基非晶纳米晶涂层的磨损失效机制为脆性疲劳剥落。     

铁基非晶纳米晶涂层组织及耐冲蚀性能的研究

利用高速电弧喷涂技术制备FeCrBSiMnNbY系非晶纳米晶涂层.采用扫描电镜、透射电镜和X射线衍射仪等对涂层的组织结构进行表征,着重分析非晶纳米晶的形成机制,并对涂层的高温耐冲蚀性能进行研究.结果表明:涂层的组织主要由非晶相和α(Fe,Cr)相纳米晶组成;其结构致密,组织均匀,孔隙率低,为1.7%;非晶纳米晶涂层具有良好的耐高温冲蚀性能,攻角增加,涂层冲蚀率随之增加;冲蚀温度升高,涂层耐冲蚀性能也随着提高.     

激光重熔对电弧喷涂含非晶相铁基涂层性能的影响

目的提高电弧喷涂含非晶相Fe基涂层的抗冲蚀及耐腐蚀性能。方法采用YAG脉冲激光器对电弧喷涂含非晶相Fe基涂层进行激光重熔处理。通过X-ray、SEM、冲蚀磨损和电化学等检测手段,研究该涂层重熔后的组织结构、冲蚀磨损性能和耐腐蚀性能。结果电弧喷涂含非晶相Fe基涂层经激光重熔后发生了晶化,并随着功率的增加,非晶含量降低,硬度也降低。重熔后,涂层与基体的结合方式由之前的机械咬合转变为冶金结合,涂层的致密度明显提高,组织缺陷减少。与喷涂层相比,0.3k W激光重熔涂层的抗冲蚀性能在30°攻角下可提高3倍,在90°攻角下可提高将近6倍。重熔层的冲蚀磨损机制在低冲角时以显微切削为主,高冲角时则以挤压破碎为主。随着激光功率的增加,重熔涂层的抗冲蚀性能降低。同时,在3.5%NaCl溶液中,重熔层的耐蚀性能随重熔激光功率的提高而提高,并且重熔层的腐蚀电流密度比喷涂层明显降低。结论激光重熔不但改善了电弧喷涂含非晶相Fe基涂层与基体间的结合状态,同时也增强了涂层的耐蚀和耐磨性能,是一种有效提升涂层性能的后处理工艺。     

高速电弧喷涂技术制备Fe基非晶涂层及其性能

利用自设的新型粉芯丝材,通过高速电弧喷涂技术制备了Fe Cr BAl Ni Si非晶涂层,针对涂层的组织结构和性能进行了深入研究。结果表明,涂层组织致密,其层状结构呈薄片形,涂层孔隙率为5.6%。涂层含有29%的非晶相,且主要存在于近基体涂层中,而晶体相则主要为Fe-Cr相、Al Ni3相、Cr B相、Ni4B3相和Al2O3相。非晶相的存在及因沉积效果产生的缺陷决定了涂层的显微硬度的不均匀性,涂层平均硬度接近800 HV0.1,最大可达1 115.3 HV0.1,属于硬质涂层。涂层的晶化温度约为712℃,较其他几种非晶涂层涂层有更好的热稳定性。     

Fe基非晶/纳米晶涂层的微结构及其在H2O2溶液中的腐蚀性能

为研究强氧化环境中,显微结构和相组成对Fe基非晶/纳米晶复合涂层的腐蚀腐蚀性能的影响,采用大气等离子喷涂(APS)技术,在1Cr18Ni9Ti不锈钢基体上喷涂制得具有不同微结构和相组成的Fe基非晶/纳米晶的复合涂层。采用XRD、SEM、TEM和DSC等检测方法对涂层的组织和相组成、晶化行为、晶化程度、内部的孔隙等微观结构进行表征。采用电化学法研究具有不同微结构和相组成的涂层在30%H₂O₂ (质量分数,下同)溶液中的腐蚀行为,探讨Fe基非晶/纳米晶复合涂层在强氧化环境中的腐蚀机理。研究表明,Mo₃Si和Fe₅Si₃相的形成使得涂层耐腐蚀性能明显降低。     

铁基非晶纳米晶涂层组织与冲蚀性能分析

利用高速电弧喷涂技术成功制备了FeCrBSiMnNbY系和FeBSiNbCr系非晶纳米晶涂层.采用扫描电镜、X射线衍射仪等设备对涂层的组织结构进行了表征,重点分析了非晶的形成机制,并对涂层的高温冲蚀性能进行了研究.结果表明,FeCrBSiMnNbY系和FeBSiNbCr系涂层的组织主要由非晶相和α(Fe,Cr)相纳米晶组成;两种涂层结构致密,组织均匀,孔隙率含量分别为1.7%和1.2%;FeBSiNbCr系非晶纳米晶涂层具有良好的耐高温冲蚀性能,随着攻角增加,涂层冲蚀率随之增加;冲蚀温度升高,涂层耐冲蚀性能也随着提高.     

AlNiFeSiB非晶纳米晶复合涂层的耐腐蚀性能研究

利用高速电弧喷涂快速冷却的技术优势,采用自动化高速电弧喷涂技术在45钢表面制备了AlNiFeSiB非晶纳米晶复合涂层。采用X射线衍射仪、扫描电镜、差示扫描量热仪分析了该涂层的组织与热物理性能;在3.5wt%NaCl溶液中检测了涂层的腐蚀性能。结果表明,AlNiFeSiB复合涂层具有非晶纳米晶复合结构,涂层非晶含量约为60%,孔隙率约为2.2%,涂层的玻璃转变温度(T_g)为409℃,开始晶化温度(T_x)为457℃;涂层的自腐蚀电位约为-553.7mV,腐蚀电流密度约为0.52μA/cm~2。     

Molybdenum based amorphous and nanocrystalline coatings prepared by high velocity oxy-fuel spraying

The high velocity oxy-fuel(HVOF) based thermal spray process has developed as a potential advantageous approach for fabricating various kinds of functional coatings.In this article,the coatings of Mo-based alloy were synthesized using the HVOF process.The microstructure and the mechanical properties of the HVOF-processed coatings were investigated using SEM,TEM,XRD,and hardness and wear tests.Annealing treatment was applied to the as-sprayed coatings to develop the microstructure and its effect on the microstructure and mechanical properties of the coatings was examined.It is found that the HVOF-processed Mo-based alloy coatings are comprised of an amorphous splat matrix embedded with nano-sized crystalline particles.Annealing at temperatures over 950 ℃ results into crystallization of the amorphous matrix.The mechanical properties of the as-sprayed coatings are enhanced with annealing temperature up to 750 ℃ and from 950 to 1050 ℃,keeps constant between 750 and 950 ℃,and reduce over 1050 ℃.The change of the mechanical property with the microstructure was illustrated in the study.     

铁基非晶合金涂层制备及应用现状

综述了铁基非晶涂层的制备技术、成形特征及显微结构,发现随着喷涂热输入的增大,涂层结构更致密,孔隙率下降,但是涂层中非晶含量降低,含氧量增加。概述了铁基非晶涂层的腐蚀性能、腐蚀行为、磨损机制的进展,并总结了铁基非晶涂层当前的工程应用现状,认为铁基非晶涂层的腐蚀性能取决于涂层化学成分和显微结构的均匀性。非晶含量越高,涂层的耐蚀耐磨性能越好;非晶的孔隙率越低,涂层的耐蚀耐磨性能更优异。但是非晶涂层的点蚀规律及机理尚未形成统一认识。依据非晶涂层的研究现状,提出了非晶涂层在制备、性能及相关机理方面存在的问题,展望了铁基非晶涂层的应用前景。     

超音速等离子喷涂非晶涂层微观结构与摩擦学性能

采用新一代超音速高能等离子喷涂(SAPS)技术制备了Fe基和Mo基两种非晶涂层,对涂层的微观结构与摩擦学性能进行对比分析。结果表明,SAPS喷涂Fe基和Mo基非晶涂层内部孔洞少、结构致密性高。与Fe基涂层相比,具有更低孔隙率的Mo基涂层在摩擦过程中表现出更低的磨损率(1.1×10^-4 μm·N^-1·s^-1),耐磨性更优。涂层的磨损机理均以磨粒磨损和疲劳磨损为主,并伴随着磨屑氧化。     

Correlation of crystallization behavior and mechanical properties of thermal sprayed PEEK coating

An amorphous PEEK coating was prepared on an Al substrate by a flame spraying process. The amorphous coating was subjected to an annealing treatment under an annealing temperature from 180 to 300 °C and a holding time from 1 to 30 min. The cold crystallization behavior of the as-sprayed coating differential scanning calorimetry (DSC) and wide angle X-ray diffraction (WAXD) measurements. The hardness and tribological behavior of the coatings were investigated. Both DSC and WAXD analysis revealed that the annealed coatings exhibited a semi-crystalline structure. Coexistence of double crystal entities in annealed coatings was deduced. The annealed coatings exhibit higher hardness, lower friction coefficient and wear rate. Both the annealing temperature and holding time can benefit the coating hardness. The annealing condition in the studied range has little influence on the tribological behavior of the coatings. The variances of the coating mechanical properties were correlated with the modifications of the coating structures induced by the annealing treatments.     

Microstructure and Corrosion Resistance of Fe-Based Coatings Prepared by Twin Wires Arc Spraying Process

FeB, FeBSi, and FeNiCrBSiNbW coatings were prepared by twin wires arc spraying process on AISI 1045 steel substrate, and the microstructure and phases were characterized by scanning electron microscope, transmission electron microscope, and x-ray diffraction. The corrosion resistance was investigated by means of electrochemical tests. It was found that FeB coating and FeBSi coating were composed of α-Fe, FeO, and Fe₂O₃ phases. FeNiCrBSiNbW coating consisted of amorphous phase and α-(Fe, Cr) nanocrystalline phase, with porosity of 1.8%, hardness of 807 Hv_0.1 and tensile bonding strength of 52.1 MPa. Three kinds of electrochemical tests were employed to identify the corrosion resistance of the coatings. The results indicated that the FeNiCrBSiNbW coating had a superior corrosion resistance, much better than FeB and FeBSi coatings. It was attributed to the amorphous/nanocrystalline structure and the presence of corrosion-resistant element Cr.     

超音速火焰喷涂Fe基非晶合金涂层材料的摩擦磨损性能研究

目的通过优化涂层制备工艺,制备致密的Fe基非晶合金涂层,以提高非晶合金涂层的耐磨性。方法采用活性燃烧高速燃气超音速火焰喷涂(AC-HVAF)技术,通过工艺优化,制备了组织致密的Fe基非晶合金涂层。利用场发射扫描电子显微镜、X射线衍射仪、维氏显微硬度计、摩擦磨损试验机、三维光学轮廓仪等设备,对非晶合金涂层的组织结构、摩擦性能和磨损机制进行了深入分析。结果 Fe基非晶合金涂层呈现典型的非晶结构,涂层厚度在300μm左右,涂层的平均显微硬度值高达1000HV0.1。在干摩擦试验条件下,Fe基非晶合金涂层的磨损量远低于304不锈钢材料,磨损率是304不锈钢基体的1/3~1/2。Fe基非晶合金涂层的磨损机制以疲劳磨损为主,伴随着氧化磨损。氧化磨损主要是由干摩擦过程中产生的摩擦热导致,氧化磨损加速了片层剥落。结论 Fe基非晶合金涂层孔隙率的降低和非晶相含量的提高,有利于稳定摩擦系数和改善涂层的耐磨损性能。     

Ni-P纳米晶镀层的摩擦学性能研究

采用化学沉积方法获得了Ni-P纳米晶和非晶两种镀层,对镀态镀层进行低温去应力退火处理。分析了镀层成分和结构,研究了组织结构和退火工艺对镀层摩擦学性能的影响规律及其内在机制。结果表明:Ni-P纳米晶镀层的摩擦学性能明显优于同条件下(仅改变镀液中的络合剂)制备的非晶镀层,镀层磨损机制发生了变化;适当地去应力退火有助于进一步提高镀层的显微硬度,达到降磨减摩的效果。     

CO2气氛和喷涂距离对电弧喷涂铁基非晶涂层组织及耐蚀性能的影响

为提高电弧喷涂铁基非晶涂层的非晶含量及耐蚀性,以CO₂为载流气体代替空气进行电弧喷涂试验,并研究喷涂距离对涂层组织与耐蚀性的影响。结果表明,喷涂层的厚度约为200 μm,涂层均主要由结晶相与非晶相构成。相比于空气介质,CO₂抑制了晶化,从而提高了涂层中的非晶含量。同时,喷涂距离对涂层的组织及耐蚀性能有较大影响。随着喷涂距离的增加,涂层中的非晶含量减少。当喷涂距离为100 mm时,涂层具有最高的开路电位-0.498 V(vs SCE)及最小的自腐蚀电流密度4.281 μA/cm²,耐蚀性能最好;当喷涂距离为150 mm时,涂层的耐蚀性最差。提高非晶含量和组织的均匀性可增强该涂层的耐蚀性能。     

电弧喷涂铁基非晶涂层的结构与性能

用电弧喷涂技术在低碳钢基体上制备一种含非晶和纳米晶的Fe基涂层.采用X射线衍射仪(XRD)、扫描电镜(SEM)、透射电镜(TEM)、显微硬度仪分析测量涂层的组织和性能.并用谢乐公式计算晶粒尺寸.结果表明,涂层呈典型的层状组织结构,由变形良好的带状粒子相互搭接堆积而成.涂层结构致密,孔隙率低,氧化物含量较少,涂层含有非晶和纳米晶,晶粒尺寸为10~40 nm,利用X射线衍射强度比较法测量涂层中非晶相的含量为55.3%.涂层具有很高的硬度,其显微硬度最高达到1 260 HV0.1.     

Effects of Annealing Below Glass Transition Temperature on the Wettability and Corrosion Performance of Fe-based Amorphous Coatings

This study investigated the effect of annealing below glass transition temperature (T_g) on the microstructural characteristics, mechanical property, wettability, and electrochemical performance of activated combustion-high velocity air fuel (AC-HVAF)-sprayed Fe-Cr-Mo-W-C-B-Y amorphous coatings (ACs). Results showed that Fe-based ACs with a thickness of ~ 300 μm exhibited a fully amorphous structure with low oxidization. Originating from the reduced free volume, sub-T_g annealing increased the thermal stability, hardness, and surface hydrophobicity of Fe-based ACs. The enhanced corrosion resistance of sub-T_g annealed ACs in 3.5 wt% NaCl solution was attributed to the increased surface hydrophobicity and passivation capability. This finding elucidates the correlation between sub-T_g annealing and the properties of Fe-based ACs, which promotes ameliorating ACs with superior performance.