硼化物层的磨料磨损特性及磨损机理

通过对磨料磨损试验和磨损表面形貌以及磨屑的观察与分析，对硼化物层的磨料磨损特性及磨损机理进行了研究，结果表明，单相硼化物层的耐磨性双相硼化物层，磨损表面有犁沟和犁沟边缘部分区域的脆性剥落，ＦｅＢ上的脆性剥落比Ｆｅ２Ｂ严重呈锯齿状，且边缘有长裂纹伸入基体，剥落的磨屑呈块状，是典型的脆性断裂，磨损过程由磨料对硼化物的微切削以及硼化层的脆性剥落控制。     

蜗轮副磨损状态监测方法试验研究

由连续运行的蜗杆传动磨损试验台上,定期提取铜基蜗轮副摩擦表面上剥落下来的磨屑,通过对磨屑的形态,大小及分布等形貌特征分析发现：铜基蜗轮副的磨损状态与其磨屑的形貌特征有着密切的关系。     

预变形对碳钢渗硼组织的影响

低碳钢（０．２０％Ｃ）渗硼后获得由ＦｅＢ层和Ｆｅ２Ｂ层组成的硼化物层;高碳钢（１．０％Ｃ）渗硼后则获得几乎由单一ＦｅＢ层组成的硼化物层。而中碳钢（０．４５％）的硼化物层则由若干个ＦｅＢ层和Ｆｅ２Ｂ层组成的亚层所构成,预变形可使低,中碳钢的硼化物层减薄,尤其当预变形量较小（２０％）或较大（６０％）时,而对于高碳钢,预变形则使其增厚,特别在中等变形量（４０％）时。     

白口铸铁的磨料磨损行为及耐磨性

通过白口铸铁的耐磨试验，观察分析材料的磨面和磨屑；研究不同性能的白口铸铁在磨料磨损时的行为机理．     

硼硫,硼氮共渗组织和性能及其机理的研究

研究了硼硫，硼氮共渗和最佳工艺及渗硼剂的最佳匹配，渗硼和硼硫，硼氮共渗的渗层组织和性能，Ｎａ２Ｓ２Ｏ３．（ＮＨ２）ＣＯ２在渗硼过程中的催渗和阻渗机制；渗层的脆性，耐磨性和耐蚀性，且证实了不仅在硼齿之间存在有Ｆｅ３（Ｃ，Ｂ）在硼化物的针舌内也存在Ｆｅ３（Ｃ，Ｂ）     

半金属摩擦材料的摩擦磨损性能及磨屑形貌

采用D－MS定速式摩擦试验机，测定了3种金属纤维（钢纤维，黄铜纤维和紫铜纤维）增强的半金属摩擦材料与灰铸铁在不同温度下滑动摩擦的摩擦磨损性能，并收集磨屑，借助SEM扫描电子显微镜，观察，分析磨屑的形貌，研究材料磨损的内在机制。研究结果表明：紫铜纤维增强的磨擦材料与灰铸铁间的摩擦因数最稳定，磨损率最低；低温时，3种材料的磨屑均比较细小，在少数大颗粒的表面可以观察较深的划痕，有的带有明显的裂纹，说明该磨损主要由犁沟及微切削作用引起；高温时，磨屑多呈较大的块状或薄片状，这是粘结剂的高温分解和摩擦表面膜的热裂分解所致；对于铜纤维（黄铜或紫铜），在摩擦过程中还会发生铜在对偶表面的涂抹现象，这也是影响其摩擦磨损性能的一个重要因素。     

硼共晶层的低应力磨粒磨损特性

本文通过磨粒磨损实验和磨损表面形貌分析,对65Mn钢表面硼共晶层的低应力磨粒磨损特性以及磨粒磨损机理进行了研究。研究表明:硼共晶组织经淬火后,具有优良的抗磨粒磨损性能。其主要磨损机理,是磨粒对马氏体的犁沟作用和显微切削作用,以及Fe_2B(Fe_3(C·B))的脆断剥落。二者互相制约又相互促进,不断进行,造成硼共晶层的磨损失效。     

冲击磨料磨损机理研究

冲击磨料磨损是一种极恶劣的磨损工况。为揭示其本质，文章中讨论了冲击磨料磨损的特点；在实验的基础上分析了几类不同性质的材料在冲击磨料磨损工况下的磨屑形成机理，得出了一些较重要的结论；提出了进一步研究的方向     

热应力组织应力对渗硼层剥落的影响

研究了Ａ３，４５和Ｔ１０钢经高频加热和电炉加热渗硼后空冷，炉冷引起渗硼层（Ｆｅ２Ｂ）“原始剥落”的原因，研究结果表明，热应力引起Ｆｅ２Ｂ折断，组织应力主要引起渗硼层表面开裂。     

低温固体硼碳氮稀土共渗及其机理探讨

研究了低温硼－碳－氮－稀土（Ｂ－Ｃ－Ｎ－ＲＥ）共渗工艺及共渗层的组织性能,并与硼－碳－氮（Ｂ－Ｃ－Ｎ）共渗工艺及共渗层的组织性能进行了比较,结果表明,低温共渗的硼化物层由ＦｅＢ、Ｆｅ２Ｂ、Ｆｅ３（Ｃ,Ｂ）等相组成,硼化物层的前沿无过渡区,ＦｅＢ和Ｆｅ２Ｂ生长过程中排挤出来的碳没有发生远程扩散,而是就近形成Ｆｅ３（Ｃ,Ｂ）等形式的硼化物。稀土加入量适当时,具有明显的催渗作用;与Ｂ－Ｃ－Ｎ共渗相比,Ｂ－Ｃ－Ｎ－ＲＥ共渗层的耐磨性和耐蚀性明显提高。对Ｂ－Ｃ－Ｎ－ＲＥ共渗的机理及稀土元素的作用作了初步的探讨。     

钢的固体深层渗硼

采用复合催渗和调整工艺参数能较好地实现钢的固体深层渗硼 .分析结果表明 :渗硼层表层由Fe2 B和FeB双相组成 ,向内Fe2 B相增加 ,FeB相减少 ,渗层呈梳齿状 ,齿的前沿过渡区较宽 ,心部组织较粗大 ;表层存在疏松和孔洞 ,且随钢中含碳量增加和合金元素的含量增加 ,渗层深度下降 ,疏松和孔洞减少 ;疏松和孔洞使表层硬度低于次表层 ,其显微硬度分布有一峰值 ,渗层显微硬度分布较为平缓     

Physical Characteristics of Plasma Cladding Fe-Cr-Nb-Si-Mo Alloy Cladding Layers on Different Substrates

A plasma cladding experiment was carried out to investigate the characteristics(surface hardness,microstructure,friction,wear properties from different substrates to the cladding layer and the bond strength) of plasma cladding Fe-Cr-Nb-Si-Mo alloy cladding layers on different substrates.In order to improve the abrasion resistance of the scraper middle trough,the plasma cladding technique was used to clad the alloy ceramic powder Ig7 on the surface of the middle trough NM450,WH60A,Hardox450,and Weartuf450 to create Fe/Cr/Nb/Mo/ V cladding layer.Based on the experiment results,the microstructure,friction and wear properties of the four cladding layers were analyzed,and the bond strength between the cladding layer and the substrate was also tested.The experimental results show that the main phases of the four cladding layers are martensite and all kinds of metal carbides ((Nb,Mo)C,VC,and Cr_7C_3).WH60A surface cladding layer has shown good friction and wear properties.     

模具材料的高温滑动冲击磨损过程的电镜观察

在模拟热作模具热磨损试验机上进行高温滑动冲击磨损试验,在各磨损阶段,用扫描电镜对模具试样表面形貌作细致观察,得出如下结论:高温滑动冲击磨损过程的主导磨损机制,早期为磨粒磨损,中期及后期逐步向点状剥落及大块疲劳剥落转移。全部过程都有粘着磨损,后期更为严重。     

稀土对45钢固体硼氮共渗过程的影响

研究了稀土对４５钢固体硼氮共渗工艺、渗层成分、组织、耐磨性及断口形貌的影响。试验结果表明,稀土的加入使渗速增大,渗层中Ｂ,Ｎ含量特别是Ｎ的含量增加,硼化物针齿变得细密、直长;且ＦｅＢ的相对含量减少,Ｆｅ２Ｂ相增加,渗层耐磨性提高,同时稀土增加了过渡区厚度,减少裂纹源。生产应用证明,稀土硼氮共渗可使烟机配件的使用寿命大幅提高。     

马氏体不锈钢等离子堆焊铁基合金组织及磨损性能

为了研究马氏体不锈钢的表面性能,采用等离子堆焊技术在Z5CND16-04不锈钢表面制备铁基合金堆焊层.采用扫描电子显微镜、能谱仪、X射线衍射仪、显微硬度计及销盘磨损实验机等检测设备,对堆焊层的组织结构、成分、硬度和磨损性能进行了研究.结果表明,铁基合金堆焊层主要由α-Fe、(Fe,Cr,Mo)7C3和(Fe,Cr,Mo)23C6相组成,添加稀土元素后相组成无明显变化.铁基合金堆焊层的硬度和耐磨性均明显高于马氏体不锈钢基材.添加适量的CeO2后,明显细化了堆焊层的显微组织.     

Friction and Wear Behavior of Modified Layer Prepared on Ti-13Nb-13Zr Alloy by Magnetron Sputtering and Plasma Nitriding

Two kinds nitride modified layers were obtained on Ti-13Nb-13 Zr surface to improve the wear property via magnetron sputtering and plasma nitriding techniques, respectively. The structures of the modified layer and the worn surface after sliding test were characterized using X-ray diffraction(XRD) and scanning electron microscopy(SEM). The friction and wear behavior of the modified layer against alumina ball was investigated in the absence of lubricant under different loads(1 N and 2 N). The X-ray diffraction analysis reveals that nitride layer is mainly composed of TiN and Ti_2N, while coating film consists of Ti N phase. Friction and wear test indicates that both modified layers can improve the wear resistance compared to untreated Ti-13Nb-13 Zr. Ti N thin film produces very hard surface, but may be easy to cause coating fracture and delamination under high normal load. However, nitride layer exhibits better wear performance. This is attributed to hard compound layer maintained its integrity with the hardened nitrogen diffusion zone during friction and wear process.     

铝合金表面油胺/微弧氧化复合膜层的耐磨性

为提高铝合金表面耐磨性能,采用微弧氧化(MAO)技术在硅酸盐电解液中对2024铝合金进行表面处理,制备微弧氧化陶瓷层;然后通过浸泡法在陶瓷层表面覆盖一层油性涂层,形成复合膜层,以期提高铝合金表面耐磨性能。利用扫描电镜(SEM)和X射线衍射仪(XRD)分别观察复合膜层的表面形貌及物相组成;利用原子力显微镜AFM测试复合膜层的表面粗糙度;利用摩擦磨损试验仪分析复合膜层的摩擦系数。在SEM的观察下复合膜层比微弧氧化陶瓷层更为平整。另外,AFM的结果显示复合膜层的表面粗糙度比微弧氧化陶瓷层降低了73%左右;摩擦磨损检测显示复合膜层的摩擦系数在0.1左右,波动幅度较小,而微弧氧化陶瓷层和铝合金的摩擦系数达0.4左右,波动幅度较大。     

Wear Properties of Plasma Transferred Arc Fe-based Coatings Reinforced by Spherical WC Particles

Fe-based coatings reinforced by spherical WC particles were produced on the 304 stainless steel by plasma transferred arc(PTA) to enhance the surface wear properties. Three different Fe/WC composite powder mixtures containing 0 wt%, 30 wt%, and 60 wt% of WC were investigated. The microstructure and phase composition of the Fe/WC composite PTA coatings were evaluated systemically by using scanning electron microscope(SEM) and X-ray diffraction(XRD). The wear properties of the three fabricated PTA coatings were investigated on a BRUKER UMT TriboLab. The morphologies of the worn tracks and wear debris were characterized by using SEM and 3 D non-contract profiler. The experimental results reveal that the microhardness on the cross-section and the wear resistance of the fabricated coatings increase dramatically with the increasing adding WC contents. The coating containing 60 wt% of WC possesses excellent wear resistance validated by the lower coefficients of friction(COF), narrower and shallower wear tracks and smaller wear rate. In the pure Fe-based coating, the main wear mechanism is the combination of adhesion and oxidative wear. Adhesive and two-body abrasive wear are predominated in the coating containing 30 wt% of WC, whereas threebody abrasion wear mechanism is predominated in the coating containing 60 wt% of WC.     

Microstructure of Ni / WC surface composite layer on gray iron substrate

The surface infiltrated composite (Ni/WC) layers on gray iron substrate were fabricated through a vacuum infiltration casting technique (VICT) using Ni-based composite powder with different WC particles content as raw materials.The microstructures of surface infiltrated composite layer,the interface structures between surface composite layer and the substrate,the changes of macro-hardness with the increasing of WC content and the micro-hardness distribution are investigated.The infiltrated composite layer includes a surface composite layer and a transition layer,and the thickness of the transition layer decreases with the increasing content of WC.The thickness of transition layer with 20%WC content in the surface infiltrated composite layer was 170 μm which was the thickest for all transition layers with different WC content.The surface composite layer was mainly composed of WC,W2C,FeB and NiB,along with Ni-Cr-Fe,Ni (Cr) solid solution,Ni (Si) solid solution and Ni (Fe) solid solution.The transition layer was composed of Ni (Cr) solid solution,Ni (Fe) solid solution,Ni (Si) solid solution,Fe (Ni) solid solution and eutectic.The surface macro-hardness and micro-hardness of the infiltrated layer had been evaluated.The macro-hardness of the surface composite layer decreases with the WC content increasing,and the average macro-hardness is HRC60.The distribution of micro-hardness presents gradient change.The average micro-hardness of the infiltrated layer is about HV1000.