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1.
为改善三元金属硅化物Fe9Cr9Si2的室温脆性,利用激光熔化沉积方法制备了铁基固溶体α增韧FegCt9Si2三元金属硅化物合金(简称α/Fe9cf9Si2合金),其组织由FegCr9Si2初生树枝晶和枝晶间铁基固溶体α组成,合金硬度随Fe9Cr9Si2初生树枝晶体积分数的增加而提高.与单相Fe9cr9Si2合金相比,铁基固溶体增韧Fe9Cr9Si2合金韧性明显改善;在干滑动摩擦条件下,α/Fe9Cr9Si2合金具有低的摩擦系数,并随Fe9cr9Si2体积分数的提高而降低.  相似文献   

2.
以Cr-Si-Ni合金粉末为原料,利用激光熔炼/快速凝固材料制备技术,制得了由金属硅化物Cr3Si及少量镍基固溶体γ组成的新型快速凝固γ/Cr3Si金属硅化物“原位”复合材料,该γ/Cr3Si金属硅化物“原位”复合材料显微组织由快速凝固初生Cr3Si树枝晶及枝晶间少量镍基固溶体γ/Cr3Si共晶组织组成。Cr3Si金属硅化物初生树枝晶体积分数随镍含量增加而减少,枝晶间γ/Cr3Si共晶组织体积分数随镍含量增加而增加。该激光熔炼/快速凝固γ/Cr3Si金属硅化物“原位”复合材料具有很高的硬度,并由于组织中韧性相镍基固溶体的存在及其细小均匀的快速凝固组织特征,而可望具有优良的强韧性配合。  相似文献   

3.
以Cr-Si-Ni合金粉末为原料,利用激光熔炼/快速凝固材料制备技术,制得了由金属硅化物Cr3Si及少量镍基固溶体γ组成的新型快速凝固γ/Cr3Si金属硅化物“原位”复合材料,该γ/Cr3Si金属硅化物“原位”复合材料显微组织由快速凝固初生Cr3Si树枝晶及枝晶间少量镍基固溶体γ/Cr3Si共晶组织组成。Cr3Si金属硅化物初生树枝晶体积分数随镍含量增加而减少,枝晶间γ/Cr3Si共晶组织体积分数随镍含量增加而增加。该激光熔炼/快速凝固γ/Cr3Si金属硅化物“原位”复合材料具有很高的硬度,并由于组合中韧性相镍基固溶体的存在及其细小均匀的快速凝固组织特征,而可望具有优良的强韧性配合。  相似文献   

4.
Cr-Cu-Si金属硅化物合金组织与耐磨性   总被引:1,自引:0,他引:1  
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。  相似文献   

5.
Ni含量对Cr13Ni5Si2/γ合金高温耐磨性能的影响   总被引:1,自引:0,他引:1  
研究了Ni含量对镍基固溶体(γ)增韧Cr13Ni5Si2三元金属硅化物合金组织及高温耐磨性的影响。结果表明,Cr13Ni5Si2/γ合金硬度及Cr13Ni5Si2初生树枝晶体积分数均随Ni含量的增加而降低。由于Cr13Ni5Si2的高硬度与Ni基固溶体γ高强韧性配合,Cr13Ni5Si2/γ合金在600℃高温滑动磨损条件下,表现出优异的耐磨性能并随合金中Ni含量增加而迅速增加。合金高温滑动磨损过程主要受Cr13Ni5Si2初生树枝晶的破碎与脱落过程控制。  相似文献   

6.
徐亚伟  王华明 《金属学报》2006,42(7):722-726
采用激光熔炼技术制备出镍基固溶体γ与Mo2Ni3Si三元金属硅化物双相合金,其显微组织由Mo2Ni3Si初生枝晶及枝晶间以γ相为主的γ/Mo2Ni3Si共晶组成.室温干滑动磨损实验表明,由于高硬度Mo2Ni3Si(hp12 Laves 相)及强韧性基体γ相的牢固结合,Mo2Ni3Si/γ双相合金具有十分优异的耐磨性能,其磨损机理是硬度较低的γ/MoaNiaSi共晶组织被优先磨损;凸出于磨损表面的部分Mo2Ni3Si初生相失去了共晶的支撑而发生开裂及剥落;另一方面,Mo2Ni3Si初生相保护基体免于严重磨损,其磨损速率最终控制合金的总磨损速率。  相似文献   

7.
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。  相似文献   

8.
方艳丽  王华明 《金属学报》2006,42(2):181-185
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.  相似文献   

9.
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.  相似文献   

10.
采用水冷铜模激光合金熔炼炉制备了以初生w树枝晶为增强相、以w2Ni3Si三元金属硅化物为基体的金属硅化物“原位”耐磨复合材料.分别在室温干滑动磨损及600℃高温滑动磨损条件下测试了上述W/W2Ni3Si金属硅化物“原位”增强耐磨复合材料的耐磨性,并讨论了其磨损机理.结果表明,上述金属硅化物耐磨复合材料在室温干滑动磨损和高温滑动磨损条件下均具有优异的耐磨性能.  相似文献   

11.
Wear resistant Cr–Cu–Si metal silicide alloys with different Cu contents were fabricated by the laser melting process. The Cr–Cu–Si alloys have a similar microstructure consisting of the Cr5Si3/CrSi dual-phase primary dendrites and the interdendritic Cu-based solid solution (Cuss). The Cu content has no effect on the phase constitutions of the alloys. The Cr5Si3/CrSi dendrite volume fraction and hardness of the Cr–Cu–Si alloys decrease with the increasing Cu content. Wear test results indicate that all the Cuss-toughened metal silicide alloys have excellent wear resistance and low coefficient of friction. Wear resistance increases and friction coefficient decreases with the decreasing Cu content.  相似文献   

12.
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。  相似文献   

13.
A wear resistant Mo2Ni3Si-based metal silicide alloy toughened by molybdenum-based solid solution (Moss) was fabricated by the laser melting deposition (LMD) manufacturing process. Microstructure of the alloy is composed of Moss primary dendrites and the matrix of the single phase Mo2Ni3Si. Wear resistance and friction coefficient of the alloys were evaluated under metallic dry sliding wear test conditions as a function of contact load. Results showed that the alloys have a low friction coefficient and outstanding wear resistance due to the high hardness of Mo2Ni3Si matrix and the high strength, ductility and toughness of Moss dendrites. The wear rate and the friction coefficient of alloys are extremely insensitive to the contact load owing to the abnormal hardness–temperature relation of Mo2Ni3Si. The Moss dendrite played the role of trapping micro-cracks and restraining brittle spalling of the Mo2Ni3Si matrix during wear process and improved the wear properties of Moss-toughened Mo2Ni3Si alloy.  相似文献   

14.
《Intermetallics》2006,14(7):750-758
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.  相似文献   

15.
Ir–Nb binary alloys doped with silicon have been used in this work to attain a three-phase fcc/L12/silicide structure. Typical Ir–Nb binary alloys, including a hypoeutectic Ir–10Nb, an eutectic Ir–16Nb, and a hypereutectic Ir–25Nb, were used as alloy bases, and Ir was further replaced by 5 at% Si. With the addition of Si, the microstructures of the Ir–(10–25)Nb–5Si ternary alloys contained three phases: fcc, L12, and compounds of Ir and Si (referred to silicide hereafter). Compressive tests from room temperature to 1500 °C showed that the Ir–10Nb–5Si alloy, with a predominant fcc microstructure, always had the highest deformation hardening rate, strength, and ductility; on the other hand, the Ir–25Nb–5Si alloy showed the worst performance. With the silicide in the microstructures, the damage sustained by the Ir–Nb–Si alloys at both room and high temperatures was dominated by interface debonding, which occurred between the fcc and the silicide or the L12 and the silicide. It is believed that the interface debonding is an instinct failure mechanism of Ir-based alloys. Additionally, a strong solid-solution hardening effect of Si acting on the fcc phase was found to occur without loss of ductility. A principle in the composition and microstructure design is proposed in this paper for further development of Ir-based alloys with Si addition. This principle is to saturate the fcc phase with Si and other alloying elements so as to achieve maximum solid-solution hardening and tie-in fine silicides homogenously distributed within the fcc by elimination of the grain boundary concentration of silicides.  相似文献   

16.
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.  相似文献   

17.
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。  相似文献   

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