钎焊工艺对WC—Co／NiCrBSi复合涂层性能的影响

采用真空钎焊技术,在４５＾＃钢基体表面焊一层（ＷＣ－Ｃｏ／ＮｉＣｒＢＳｉ）复合涂层,研究了不同钎焊工艺对涂层自身结合强度、涂层与基体间连接强度以及涂层抗磨料磨损性能的影响。钎焊工艺为１０８０℃×１０ｍｉｎ时,涂层自身结合强度为１４６ＭＰａ;涂层与基体间的最高连接强度为３６７ＭＰａ。涂层的抗磨料磨损性能比Ｃｏ－Ｃｒ－Ｗ堆焊涂层和（ＷＣ－Ｃｏ／ＮｉｒＢＳｉ）火焰堆焊层的高。     

（WC—Co／NiCrBSi）钎焊涂层结合机制及磨损性能研究

采用真空钎焊工艺,将ＷＣ－Ｃｏ硬质合金粉和ＮｉＣｒＢＳｉ（ＡＷＳＢＮｉ－２）合金粉钎焊到４５＃钢表面,得到（ＷＣ－Ｃｏ／ＮｉＣｒＢＳｉ）钎焊涂层。     

喷焊（涂）层厚度及其后处理与组织性能关系的研究

对以２０ＣｒＮｉＭｏ钢为基材、喷焊Ｎｉ－Ｃｒ－Ｂ－Ｓｉ自熔合金粉＋ＷＣ颗粒的涂层及其后处理进行了研究；测定了涂层的硬度、耐磨性以及结合层的元素扩散；观察了表层结构。结果表明，厚度和冷却方式对喷涂层的耐磨性有显著影响。     

喷焊（涂）层厚度及其后处理与组织性能关系的研究

对以２０ＣｒＮｉＭｏ钢为基材，喷焊Ｎｉ－Ｃｒ－Ｂ－Ｓｉ自熔合金粉＋ＷＣ颗粒的涂层及其后处理进行了研究。测定了涂层的硬度，耐磨性以及结合层的元素扩散；观察了表层结构，结果表明，厚度和冷却方式对喷涂层的耐磨性有显著影响。     

Al2O3／SiC纳米复合陶瓷与配副在熔融锌中的磨蚀

本文将Ａｌ２Ｏ３／ＳｉＣ纳米复合陶瓷分别与Ｃｒ２５Ｎｉ５合金,Ｃｏ－Ｃｒ－Ｗ合金及烧结Ｗ环三种配制材料在４６５℃的熔融锌液中进行环－块腐蚀磨损实验。结果表明耐锌腐蚀是各种材料耐磨的前提。Ｗ（环）与Ａｌ２Ｏ３／ＳｉＣ纳米复合陶瓷（块）是最佳的摩擦副。     

电镀

９９０９００１　Ｃｒ镀层、Ｎｉ－Ｐ、Ｎｉ－Ｍｏ、Ｎｉ－Ｗ－Ｐ和Ｍｎ－Ｚｎ合金镀层性能比较——ＡｇｌａｄｚｅＴ．ＴｒａｎｓＩｎｓｔＭｅｔａｌＦｉｎ,１９９７,７５（１）∶３０（英文）研究了Ｃｒ镀层、Ｎｉ－Ｐ、Ｎｉ－Ｍｏ、Ｎｉ－Ｗ－Ｐ和Ｍｎ－Ｚｎ合金镀层性能与电流效率／电流密度比值、热处理前后（对Ｎｉ－Ｐ合金镀层而言）镀层应力和显微硬度的关系。研究了热处理和放电处理对高硬度Ｎｉ－Ｗ－Ｐ合金镀层的影响,用比色分析法分析了各种镀层。详细介绍了电沉积Ｍｎ－Ｚｎ合金［含２５％（ｗｔ）Ｚｎ］的槽液成分、极化曲…     

Ni_3Al(IC-6)合金防护涂层抗氧化性能研究

Ｎｉ３Ａｌ合金是一种新型高温合金，ＩＣ－６合金是不含Ｃｒ而含１４％Ｍｏ的Ｎｉ３Ａｌ合金。由于高温下Ｍｏ极易氧化升华，因此为使ＩＣ－６合金在高温下可靠工作，需选择ＮｉＣｒＡｌＸ涂层作为ＩＣ－６合金的保护涂层。采用磁控溅射技术，在专用装置上按通过系统研究提出的工艺涂覆ＮｉＣｒＡｌＸ涂层，并对其抗周期氧化性能进行了研究。试验表明：ＮｉＣｒＡｌＹＳｉ涂层对ＩＣ－６合金的防护是非常有效的。     

航空用新型超高强度钢16NiCo

１６ＮｉＣｏ是可焊接超高强度钢，主要成分是０．１６Ｃ－２Ｃｒ－１０Ｎｉ－１Ｍｏ－１４Ｃｏ。靠二次硬化获得所需强度。使用状态下的基体组织为板条马氏体，主要强化相是沿位错线分布的Ｍ＿２Ｃ。力学性能的典型值为抗拉强度σ＿ｂ１７４０ＭＰａ，断裂韧度Ｋ＿（ＩＣ）值为１５３ＭＰａ，Ｋ＿（ＩＳＣＣ）值为８２ＭＰａ。工艺性能良好，可用于制造受力接头、平尾大轴、着陆钩和起落架零件。     

金属-陶瓷复合涂层摩擦学特性的SEM和SEAM研究

在ＳＲＶ摩擦磨损试验机上进行常温干摩擦试验,比较了ＣｏＣｒＭｏＳｉ＋Ａｌ_２Ｏ_３ＺｒＯ_２和ＣｏＣｒＭｏＳｉ＋Ｆｅ_３Ｏ_４两种大气等离子喷涂金属－陶瓷复合涂层以及Ｃ１Ｍｎ１Ｃｒ１碳钢涂层与３５＃中碳钢对磨的摩擦学特性;利用扫描电子显微镜（ＳＥＭ）和扫描电声显微镜（ＳＥＡＭ）观察了磨损表面和亚表层的显微结构,分析了金属－陶瓷复合涂层的磨损机理．结果表明,粘着磨损占主导地位,同时存在微切削和微裂纹的扩展、连接．     

Ni－Cr－Co－B钎料钎焊K3合金接头组织研究

采用金相分析、电子探针及Ｘ射线衍射等试验手段确定了Ｎｉ－Ｃｒ－Ｃｏ－Ｂ钎料及其钎焊的Ｋ３合金接头的相组成，研究了钎焊工艺参数和焊后扩散热处理对这类接头组织的影响，并与ＢＮｉ－ｌａ钎料钎焊的Ｋ３合金接头进行了对比。对采用Ｎｉ－Ｃｒ－Ｃｏ－Ｂ钎料和ＢＮｉ－ｌａ钎料钎焊的Ｋ３合金接头室温冲击韧性进行了对比评定。     

Microstructure and Properties of WC-Co/NiCrBSi Brazing Coating

1.IntroductionModernengineeringapplicati0nsshowthatagreatamount0fdamagethatmaterialssh0wisrelatedt0surfacewear.Byusingcoatingtechniques,itisp0ssi-blet0pr0tectagainstwear.Theadvantages0fcoat-ingarealongerservicelifeperf0rmanceresultingfr0moptimizedmaterialcombinationsandaconsequentre-ductionofcost.Thesurfacepr0pertiesofstructuralcomp0nentsin0ilandmineindustrieshavesostr0nginflllence0ntheirbehavi0rthatseveralsurfacemodi-ficationshavebeenusedinthosepr0fessions,suchasthermalspraying,surface0verlay…     

WC-17Co含量对(WC-17Co/NiCrBSi)复合钎焊涂层结合性能及耐磨性的影响

用真空钎焊方法,在45^#钢基体表面钎焊一层WC-17Co/NiCrBSi耐磨涂层（厚1.5mm）。研究了WC-17Co含量对涂层性能的影响。涂层自身结合强度随WC-17Co含量的增加而增大,当涂层中WC-17Co含量为69wt%时,涂层结合强度达184MPa。涂层的抗磨料磨损性能高于火焰堆焊WC-17Co/NiCrBSi涂层和CoCrW堆焊涂层。     

Brazing of WC–8Co cemented carbide to steel using Cu–Ni–Al alloys as filler metal: Microstructures and joint mechanical behavior

Three novel Cu–Ni–Al brazing filler alloys with Cu/Ni weight ratio of 4:1 and 2.5–10 wt% Al were developed and characterized, and the wetting of three Cu–Ni–Al alloys on WC–8 Co cemented carbide were investigated at 1190–1210?C by the sessile drop technique. Vacuum brazing of the WC–8 Co cemented carbide to SAE1045 steel using the three Cu–Ni–Al alloys as filler metal was further carried out based on the wetting test results. The interfacial interactions and joint mechanical behaviors involving microhardness, shear strength and fracture were analyzed and discussed. The experimental results show that all the three wetting systems present excellent wettability with final contact angles of less than 5?and fast spreading. An obvious degeneration layer with continuous thin strip forms in the cemented carbide adjacent to the Cu–Ni–Al/WC–8 Co interface. The variation of microhardness in the joint cross-section is closely related to the interactions(such as diffusion and solid solution) of WC–8 Co/Cu–Ni–Al/steel system. Compared with the other two brazed joints, the WC–8 Co/Cu–19 Ni–5 Al/steel brazed joint presents more reliable interlayer microstructure and mechanical property while brazing at the corresponding wetting temperatures for 5 min, and its average shear strength is over 200 MPa after further optimizing the brazing temperature and holding time. The joint shear fracture path passes along the degeneration layer, Cu–Ni–Al/WC–8 Co interface and brazing interlayer, showing a mixed ductile-brittle fracture.     

爆炸喷涂WC-Co涂层结合强度的测量方法及喷涂工艺研究

设计了一种新的测量方法用于测量爆炸喷涂涂层与基体的结合强度，从理论上分析了这种方法拉伸面的临界尺寸，实验结果表明，对国产喷枪尺寸设计为2mm左右是合适的，爆炸喷涂涂层与基体的结合离最高可达143MPa.为避免喷涂过程中金属Co的损失，获得较好的显微形,爆炸气体中C2H2需要过量，O2/C2H2(摩尔比）为1．5左右较合适。     

钎剂保护法WC／Cu基钎涂层的制备及其性能

目前,比较成熟的钎涂工艺基本上采用真空或气保护的方法,而仅以钎剂作保护实现钎涂加工的方法鲜有报道。为此,采用钎剂作保护,通过炉中钎焊的方法在Q235A钢表面制备了WC／Cu复合材料耐磨涂层,并通过组织观察和力学性能测试考察了钎涂层的性能。结果表明,使用粉状铜基钎料在大气环境下焊出的涂层气孔、渣孔等缺陷情况为：当涂层厚度...     

Effect of bonding time on joint properties of vacuum brazed WC – Co hard metal/carbon steel using stacked Cu and Ni alloy as insert metal

Abstract

Hard metal WC – Co and carbon steel were successfully joined using double layered Cu alloy and amorphous Ni alloy as inert metal and an oil cooling method after brazing. Defects such as cracks and voids were not formed near the bonded zone. This result means that double layered insert metals and oil cooling minimised the residual stress near the bonded zone after brazing. The shear strength of the joints decreased with increasing bond time. The reasons why the shear strength decreased as bond time increased could be many, including shape of the interface, formation and growth of brittle intermetallic compounds, and coarsening of WC particles near the bond zone. The maximum shear strength of the joints was 310 MPa under conditions 0·6 ks bond time and 8 wt-%Co content in the WC hard alloy.     

等离子喷涂NiCrBSi增强Mo涂层的组织结构和断裂韧性

为了开发既具有较高硬度、可防止黏着磨损、又具有一定孔隙能够储存润滑油的用于气缸内壁和活塞的热喷涂层,采用等离子喷涂制备了纯Mo和Mo-28%NiCrBSi复合涂层,采用图像法定量表征了涂层的孔隙率,采用压痕法测试了涂层的硬度和断裂韧性,研究了添加NiCrBSi对等离子喷涂Mo层的组织结构、孔隙率、硬度和断裂韧性的影响,并与某进口防黏着磨损Mo涂层进行比较。结果表明:等离子喷涂Mo-28%NiCrBSi复合涂层的孔隙率比纯Mo涂层略高,硬度为(561±83)HV3 N,比纯Mo涂层提高19%,比服役过的进口纯Mo涂层高约40%;复合涂层的断裂韧性为8.9 MPa"m1/2,约为纯Mo涂层的4倍,接近Mo块材。     

Influence of loading levels on RCF life and failure mode of Ni-based alloy and WC–Ni ceramic composite coatings

This paper studied influence of loading levels on rolling contact fatigue (RCF) performance of NiCrBSi/WC–Ni composite coating. The results showed that abrasion, spalling, delamination, and rolling cracking were four kinds of main failure modes related with contact stress. Under relatively high contact stress, intense deformation of NiCrBSi particles resulted in rolling cracking failure. Furthermore, RCF life can be predicted by established lognormal distribution and σ_max − N model. The study also found that RCF life was closer to expectation E(N), higher failure probability of the coating. And RCF life became more discrete and more difficult to predict as contact stress increased.     

Microstructure of Nanostructured WC-Co Coating Prepared by Thermal Spraying

Nanostructured WC-Co coatings were produced with Atmospheric Plasma Spraying (APS) and Low Pressure Plasma Spraying (LPPS). Microstructure characteristics and phase compositions of the coatings were studied by means of scanning electron microscopy (SEM) and X-ray diffraction (XRD) respectively. The microstructure compositions were analyzed with EDS. During APS deposition the existence of oxygen causes the decarburization of the coating, and the coating was composed of melted area and the WC/12Co powder. Besides WC phase, there was W2C phase. However in the coating deposited by LPPS the content of oxygen was so low that there were a limit degradation of the WC/12Co powder. The coatings were made up of compact block and loosen porosity area. There were large quantities of nanostructure WC grains and a small quantity of microstructure WC grains presented in the coating. Besides WC phase, a little W2C and WC1-x or Co6W6C phases occured. Consideration of the characteristics of the highly porous, spherical-shell morphology of nano-WC/12Co power, heterogeneous melting and localized superheating of the power were two main factors which caused the microstructure and phase composition of nano-WC-Co coatings.     

化学镀镍对碳纤维增强聚酰亚胺表面WC/Co涂层抗热震性能的影响

在航空发动机涡轮叶片用碳纤维增强聚酰亚胺(C/PMR15)复合材料表面喷涂WC/Co涂层可以提高其抗氧化耐冲刷性能,采用整体热震法能够评定涂层与基体的结合力.研究了在C/PMR15基体上化学镀镍作为粘结底层对WC/Co喷涂层抗热震性能的影响,并与喷涂PMR15粉末作为过渡层的方法进行了比较.结果表明,在PMR15过渡层上不能得到完整的后续涂层,在化学镀镍粘结底层上可得到连续致密的镍基合金层和WC/Co涂层,镀镍层大幅度提高了基体抗氧化能力,缓和了WC/Co涂层和基体界面位置的热应力,涂层抗热震性提高.