WC及黑钨矿粉末对Ni74Al26基复合材料性能影响研究

发布时间：2018-04-04 18:30

本文选题：黑钨矿　切入点：WC　出处：《辽宁工程技术大学》2015年硕士论文

【摘要】：为了改善Ni74A126基复合材料的现有不足,向Ni74A126体系中掺杂不同含量的WC粉末和天然黑钨矿粉末以及一定量的Cr粉与黑钨矿粉的混合粉末,采用激光引燃自蔓延烧结合成技术制备颗粒增强Ni74A126基复合材料。利用OM、XRD进行微观组织表征及物相结构分析,并表征硬度、耐磨性和耐蚀性能等宏观力学性能,初步探讨WC粉末、黑钨矿粉末以及Cr元素与黑钨矿粉末的协同作用对复合材料的微观组织结构及宏观力学性能的影响规律。结果表明：Ni74A126基体中主要物相为α-Ni、NiAl、Ni3Al和A1203,组织形态为针状与胞状混合；掺杂WC粉末后复合材料产物中出现WC,Ni4W等新相,针状晶转变为细小的胞状晶；掺杂黑钨矿粉末后复合材料产物出现Ni4W和WO3等新相,晶粒形态没有明显变化但尺寸明显变小；WC粉末和黑钨矿粉末的添加,在一定范围内提高了复合材料的致密性、硬度、耐磨性。当WC粉末含量为1%时,材料的孔隙率最小,为6.08%,硬度达到最高,为187.3HV,磨损率最低,为1.13mg/mm2,综合性能最佳；当黑钨矿粉末含量为2%时,材料的孔隙率最小,为6.38%,硬度值最大,为181.7HV,磨损率最低,为1.01mg/mm2,综合性能最佳；但WC与黑钨矿粉末的添加并没有提高材料的耐蚀性。向Ni74A126基体中添加5%Cr粉后再添加不同含量的黑钨矿粉末使得复合材料的耐蚀性得以显著提高,当黑钨矿添加量为1%时,材料腐蚀电流密度最小,为46.71μA/cm2,材料的耐蚀性达到最好,综合力学性能最佳。
[Abstract]:In order to improve the existing deficiency of Ni74A126 matrix composites, different contents of WC powder, natural wolframite powder and mixed powder of Cr powder and wolframite powder were doped into Ni74A126 system.Particle reinforced Ni74A126 matrix composites were prepared by laser ignited self-propagating sintering (SHS) synthesis.The microstructure and phase structure of WC powder were analyzed by OMG-XRD, and the macroscopic mechanical properties, such as hardness, wear resistance and corrosion resistance, were characterized, and the WC powder was preliminarily discussed.The influence of wolframite powder and the synergistic action of Cr and wolframite powder on the microstructure and macroscopic mechanical properties of the composites.The results show that the main phases in the matrix are 伪 -NiNI-NiAlNi3Al and A1203, and the microstructure is acicular and cellular mixed, and after doping WC powder, some new phases, such as WCG-Ni4W, are found in the composites, and the needle-like crystals are transformed into fine cellular crystals.After doped wolframite powder, some new phases such as Ni4W and WO3 appeared in the composites, but the grain morphology was not obviously changed, but the size of WC powder and wolframite powder were obviously reduced. The compactness and hardness of the composites were improved in a certain range.Wear resistance.When the WC powder content is 1, the porosity of the material is the smallest, 6.08, the hardness reaches the highest, 187.3 HVV, the wear rate is the lowest, 1.13 mg / mm2, the comprehensive property is the best; when the wolframite powder content is 2, the porosity of the material is the minimum, 6.38 and the hardness is the largest.At 181.7 HVV, the wear rate was the lowest, 1.01mg / mm2, and the comprehensive properties were the best, but the addition of WC and wolframite powder did not improve the corrosion resistance of the materials.After adding 5%Cr powder to Ni74A126 matrix and adding wolframite powder with different content, the corrosion resistance of the composite was improved significantly. When the content of wolframite was 1, the corrosion current density of the composite was the lowest, which was 46.71 渭 A / cm ~ 2, and the corrosion resistance of the composite was the best.Comprehensive mechanical properties are the best.
【学位授予单位】：辽宁工程技术大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB333

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