激光熔敷Cr2Ni3Si／Cr3Si金属硅化物复合材料涂层组织与高温耐磨性

以Cr-Si-Ni高纯预合金化粉末为原料、利用激光熔敷技术在奥氏体不锈钢1Cr18Ni9Ti表面上制得了以金属硅化物Cr3Si为增强相、以复杂多元金属硅化物Cr-Ni-Si为基体的快速凝固金属硅化物复合材料冶金涂层，分析了该涂层的显微组织，在高温滑动磨损条件下测试了其耐磨性能。研究结果表明，Cr3Si金属硅化物的体积分数对激光熔敷Cr2Ni3Si／Cr3Si复合材料涂层的硬度和高温耐磨性有显著影响。由于涂层中硬质耐磨相Cr3Si的抗磨骨干作用，在高温滑动磨损条件下该涂层具有优良的耐磨性能。     

激光熔覆Mo2Ni3Si／NiSi金属硅化物复合材料涂层组织与耐磨性

以39Mo-35Ni-26Si(w％)合金粉末为原料，采用激光熔覆技术，在1Cr18Ni9Ti不锈钢基材表面翩得以Mo2Ni3Si金属硅化物为初生相，以Mo2Ni3Si／NiSi共晶相为基体的金属硅化物耐磨复合材料涂层。涂层的常温干滑动磨损试验结果表明，在磨损过程中，Mo2Ni3Si／NiSi共晶相轻微地优先磨损，Mo2Ni3Si金属硅化物微微凸出于磨损表面，起到抗磨的骨干作用。由于Mo2Ni3Si金属硅化物具有很高的硬度和很强的原子间键合力，在磨损过程中难于变形和粘着，激光熔覆Mo2Ni3Si／NiSi金属硅化物复合材料涂层具有优异的耐磨性，与1Cr18Ni9Ti标样相比，涂层的耐磨性提高了56倍。     

激光熔敷Ti5Si3／NiTi金属间化合物复合材料涂层组织与耐磨性

以Ti14Si6Ni80合金粉末为原料，利用激光熔敷技术在BT9钛合金表面制得以金属硅化物Ti5Si3为增强相、以金属间化合物NiTi为基体的快速凝固金属间化合物复合材料涂层，分析了该涂层的显微组织，在室温干滑动磨损条件下测试了其耐磨性。研究结果表明，涂层硬度高、组织致密、与基材之间为完全冶金结合，在干滑动磨损试验条件下具有较好的耐磨性。涂层具有优异耐磨性的主要原因是作为耐磨增强相的金属硅化物Ti5Si3具有高硬高耐磨的特性，在涂层中起到了抗磨骨干作用，同时作为涂层基体的金属间化合物NiTi由于具有极强的原子结合键及应力诱发马氏体相变特性，本身具有优异的耐磨性，在摩擦过程中对耐磨增强相Ti5Si3起到了强力支撑作用。     

激光熔化沉积Ti5Si3/NiTi双相金属间化合物合金耐磨性能

采用激光熔化沉积工艺制备出以块状Ti5Si3过渡金属硅化物为初生相、以Ti5Si3/NiTi共晶为基体的双相金属间化合物耐磨合金,在室温干滑动磨损条件下测试了Ti5Si3/NiTi合金的耐磨性能并讨论了其磨损机制。结果表明,由于Ti5Si3/NiTi合金良好的强韧性配合以及在磨损过程中磨损表面上形成了“无组织特征”的表面高硬度层,对合金有保护作用,合金在室温干滑动磨损条件下具有优异的耐磨性能和很低的载荷敏感性     

激光熔炼Ti5Si3-TiCo-Ti2Co多相金属间化合物合金的组织与耐磨性

利用激光熔炼技术制备出Ti5Si3-TiCo-Ti2Co多相金属间化合物新型耐磨合金，分析了合金的显微组织并测试了合金的室温干滑动磨损性能。结果表明，Ti5Si3-TiCo—Ti2Co多相金属间化合物耐磨合金组织均匀、致密，在室温干滑动磨损条件下具有优异的耐磨性能。Ti5Si3-TiCo—Ti2Co多相金属间化合物耐磨合金的磨损量随磨损时间的延长缓慢增加，磨损率先增加后降低；难熔金属硅化物Ti5Si3的高硬度及金属间化合物的反常屈服强度一温度关系及磨损过程中表面粘附转移保护层的形成，是Ti5Si3-TiCo—Ti2Co多相金属间化合物耐磨合金在室温干滑动磨损试验条件下具有较好耐磨性能的原因。     

Cr-Cu-Si金属硅化物合金组织与耐磨性

利用激光熔炼材料制备技术，制得了由铜基固溶体增韧的Cr5Si3／CrSi金属硅化物新型耐磨合金，分析了合金的显微组织结构，测定了合金的显微硬度，考察了合金在室温干滑动磨损条件下的耐磨性能。研究结果表明：Cr-Cu-Si金属硅化物合金显微组织由Cr5Si3金属硅化物初生树枝晶、CrSi相的初生树枝晶及枝晶间铜基固溶体组成，由于金属硅化物Cr5Si3及CrSi的高硬度、强原子间结合力与铜基固溶体的优异导热性、摩擦相容性，上述激光熔炼Cr-Cu-Si金属硅化物合金材料在室温滑动干摩擦试验条件下表现出优异的耐磨性。     

钛合金表面激光熔敷Cr13Ni5Si2基金属硅化物涂层组织与耐磨性

以Cr-Ni-Si合金粉末为原料、利用激光熔敷技术在钛合金表面上制得了Cr13Ni5Si2基金属硅化物冶金涂层，在于滑动磨损条件下测试了该涂层的耐磨性能。结果表明，激光熔敷Cr13Ni5Si2基金属硅化物涂层组织主要由Cr13Ni5Si2初生树枝品及少量Cr13Ni5Si2／Cr13Ni5Si2共晶组成，涂层在干滑动磨损条件下具有优异的耐磨性能。     

ROOM-TEMPERATURE SLIDING WEAR PROPERTIES OF LASER MELT DEPOSITED Cr13Ni5Si2/γ TERNARY METAL SILICIDE ALLOY

采用激光熔化连续沉积工艺制备出了以Cr13NisSi2为初生相、以γ-Ni基固溶体为增韧相的金属硅化物耐磨合金，在室温干滑动磨损条件下测试了Cr13NisSi2／γ合金的耐磨性能并讨论了其磨损机理．结果表明，由于Cr13NisSi2／γ合金优良的强韧性配合以及在磨损过程中磨损表面上稳定氧化物转移覆盖层的快速形成，合金在室温干滑动磨损条件下具有优异的耐磨性能和很低的载荷敏感系数．     

激光熔覆镍基硅化物涂层研究现状

综述了激光熔覆镍基三元金属硅化物涂层的研究现状。对Ni-Cr-Si、Ni-Mo-Si、Ni-Ti-Si体系的金属硅化物涂层的研究现状进行了总结。其中,二元金属硅化物Cr3Si、Mo Si2及Ti5Si3硬质相的高熔点、高强度和抗氧化性使其成为高温结构材料研究的对象。三元金属硅化物Mo2Ni3Si、Ti2Ni3Si及W2Ni3Si具有高硬度和一定的韧性,其作为强化相制备的激光熔覆涂层具有良好的摩擦磨损性能。     

等离子熔覆铁基金属陶瓷复合涂层的耐磨性能

采用等离子熔覆技术,在调质C级钢表面原位生成铁基金属陶瓷复合材料涂层。利用SEM,XRD和EDS等分析了涂层的显微组织：在室温干滑动磨损及高温滑动磨损条件下测试了涂层的耐磨性,并讨论了磨损机理：结果表明,涂层由Cr7C3增强相和γ-Fe固溶体与少量CrC3构成的共晶组成;涂层组织细密,无大的显微孔洞及裂纹。由于占涂层体积分数较高的耐磨增强相Cr7C3的存在,使涂层在室温磨损试验条件下随载荷增加而磨损质量损失增加极为缓慢,对载荷变化不敏感;400～600℃高温滑动磨损条件下,试验温度越高,涂层的耐磨优势越明显。涂层在室温和高温干滑动磨损条件下磨损表面都比较光滑,均具有优良的耐磨性能。     

Microstructure and dry sliding wear resistance of a Cr13Ni5Si2 ternary metal silicide alloy

Wear resistant Cr–Ni–Si metal silicide alloy with a microstructure primarily consisting of ternary metal silicide Cr₁₃Ni₅Si₂ primary dendrites was fabricated by the laser melting (Lasmelt) process using Cr–Ni–Si elemental powder blends as the precursor materials. Microstructure of the alloy was characterized by optical microscopy, scanning electron microscopy, X-ray diffraction and energy dispersive X-ray analysis. Wear resistance of the Cr₁₃Ni₅Si₂ alloy was evaluated under dry sliding wear test conditions at room temperature. Results indicate that the Cr₁₃Ni₅Si₂-based metal silicide alloy has excellent wear resistance under dry sliding wear test conditions.     

Elevated temperature wear behaviors of a Co–Mo–Si ternary metal silicide alloy

Wear resistant Co–Mo–Si ternary metal silicide alloy consisting of Co₃Mo₂Si primary dendrite and the interdendritic ductile Co-base solid solution (Co_ss) was designed and fabricated by the laser melting process. The alloy exhibited strong abnormal load- and temperature-dependence of wear under elevated temperature metallic sliding wear test conditions.     

A wear resistant ductile metal-toughened Cr13Ni5Si2 ternary metal silicide alloy

A ductile metal-toughened Cr–Ni–Si ternary metal silicide wear resistant alloy with a dual-phase microstructure consisting of Cr₁₃Ni₅Si₂ ternary metal silicide primary dendrites and the interdendritic nickel-base solid solution (γ) was designed and fabricated by the laser melting/continuous deposition process. Wear resistance of the γ-toughened Cr₁₃Ni₅Si₂ intermetallic alloy was evaluated on an MM-200 block-on-wheel dry sliding wear tester at room temperature. The γ-toughened Cr₁₃Ni₅Si₂ intermetallic alloy has excellent wear resistance and extremely low load-sensitivity of wear under dry sliding wear test conditions due to the inherent high hardness, abnormal hardness–temperature relation and strong covalent-dominant atomic bonds. The isolated toughening γ phase played a positive role in reducing volume wear rate by retarding crack propagation and preventing pull-out of the broken Cr₁₃Ni₅Si₂ fragments from the wear surface.     

Microstructure and tribological properties of laser clad Ti2Ni3Si/NiTi intermetallic coatings

Wear resistant Ti₂Ni₃Si/NiTi full intermetallic composite coatings with a microstructure consisting of ternary metal silicide Ti₂Ni₃Si primary dendrites and interdendritic Ti₂Ni₃Si/NiTi eutectic were fabricated on a substrate of 0.2%C low carbon steel by the laser cladding process using Ti-Ni-Si alloy powders as the precursor materials. Microstructure of the coatings was characterized by optical microscopy (OM), scanning electron microscopy (SEM), X-ray diffraction (XRD) and energy dispersive X-ray analysis (EDS). Wear resistance of the laser clad Ti₂Ni₃Si/NiTi intermetallic coatings was evaluated under dry sliding wear test conditions at room temperature. Results indicate that the Ti₂Ni₃Si/NiTi intermetallic coatings have excellent abrasive and adhesive wear resistance under dry sliding wear test conditions because of the unique combination of high yield strength and toughness of the intermetallic compound NiTi and the high hardness, strong covalent dominant atomic bonds and possible strong hardness anomaly of the ternary metal silicide Ti₂Ni₃Si with MgZn₂ type Laves crystal structure.     

Ti2Ni3Si/NiTi金属间化合物合金在H2SO4溶液中的腐蚀行为

利用激光熔炼材料制备技术,制得了由三元金属硅化物Ti2Ni3Si初生枝晶和枝晶间Ti2Ni3Si/Ti共晶组成的金属间化合物耐磨耐蚀合金;采用极化曲线、塔菲尔图(Tafel Plot)和交流阻抗(EIS)等技术,研究了合金在1 mol/L H2SO4溶液中的电化学腐蚀行为以及Ti含量对合金组织与耐蚀性的影响.结果表明:由于表面形成的稳定钝化膜及Ti2Ni3Si和NiTi的高化学稳定性,使合金在1 mol/L H2SO4溶液中具有优异的耐蚀性,且随着Ti含量的升高,合金的耐蚀性略有提高.     

Microstructure and tribological properties of NiMo/Mo2Ni3Si intermetallic “in-situ” composites

Wear resistant NiMo/Mo₂Ni₃Si intermetallic “in-situ” composites with a microstructure of ternary metal silicide Mo₂Ni₃Si primary dendritic, the long strip-like NiMo intermetallic phase, and a small amount of Ni/NiMo eutectics structure were designed and fabricated using molybdenum, nickel and silicon elemental powders. Friction and wear properties of NiMo/Mo₂Ni₃Si composites were evaluated under different contact load at room-temperature dry-sliding wear test conditions. Microstructure, worn surface morphologies and subsurface microstructure were characterized by OM, XRD, SEM and EDS. Results indicate that NiMo/Mo₂Ni₃Si composites have low fiction coefficient, excellent wear resistance and sluggish wear-load dependence. The dominant wear mechanisms of NiMo/Mo₂Ni₃Si composites are soft abrasion and slightly superficial oxidative wear.