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1.
传统的耐磨钢铁材料难以满足现代矿山装备对关键耐磨部件的需求,陶瓷颗粒增强钢铁基耐磨复合材料成为最具良好应用前景的耐磨材料之一。通过预烧结获得不同体积分数及不同颗粒大小的陶瓷预制体,结合铸渗法制备出氧化锆(ZrO2)增韧氧化铝(Al2O3)陶瓷颗粒增强高铬铸铁(HCCI)基复合材料。结果表明:随着ZTA(ZrO2增韧Al2O3)颗粒体积分数(25%~45%)的增加,ZTA颗粒等效直径(1.7,1.2,0.4 mm)减小,复合材料抗冲击磨损性能随之提高,以颗粒体积分数为45%、等效粒径为0.4 mm时最佳。ZTAp/HCCI复合材料的主要磨损特征是磨损面发生微切削,其主要磨损机制是磨料磨损。  相似文献   

2.
通过传统重力浇注工艺,用高铬铸铁金属溶液铸渗ZrO2增韧Al2O3(ZTA)陶瓷颗粒蜂窝状预制体,从而获得高铬铸铁基蜂窝陶瓷复合材料。将复合材料在930℃、980℃、1 030℃、1 080℃温度下淬火,并分别在230℃、330℃、430℃、530℃时回火,研究了热处理条件对高铬铸铁基蜂窝陶瓷复合材料组织及三体磨料磨损性能的影响。研究结果表明:在相同回火温度条件下,随着淬火温度的升高,复合材料硬度升高,其耐磨性也随之升高;在相同淬火温度条件下,随着回火温度的升高,材料的硬度及耐磨性能也随之升高,两者达到一定温度后其硬度及耐磨性都下降,材料耐磨性与材料的硬度变化趋势一致。最终得到复合材料的最佳热处理工艺为:1 030℃×2h,空冷+530℃×0.5h。  相似文献   

3.
将粒径为1~2 mm的ZrO2增韧Al2O3陶瓷颗粒(ZTAp)、高铬合金粉末和黏结剂混合真空烧结制备蜂窝状预制体,再浇注高铬铸铁液制备出ZTAp增强高铬铸铁基复合材料。采用SEM、EDS、XRD分析复合材料的界面微观结构和物相组成,通过三体磨损试验评价复合材料的耐磨性能。结果表明,烧结高铬铸铁基体在铸造过程中发生重熔,与铸造高铬铸铁基体呈冶金结合,ZTAp与金属基体界面结合致密,无裂纹、气孔等缺陷。复合材料三体耐磨性能达到高铬铸铁的3倍以上。将该复合材料应用于制备磨辊件,经过5 000 h服役,柱状区和复合区在磨辊半径方向上的磨损量分别为8.2 mm、5.9 mm,预计寿命可达到高铬铸铁磨辊的2倍以上。   相似文献   

4.
采用往复式滑动摩擦磨损(SRV)试验机研究了高铬铸铁及三维网络结构Al2O3陶瓷增强高铬铸铁复合材料的干摩擦磨损性能,测量了高铬铸铁和Al2O3陶瓷/高铬铸铁复合材料在不同摩擦频率及载荷下的摩擦系数和磨损率;用扫描电镜观察磨损表面形貌,并分析了三维网络Al2O3陶瓷对复合材料磨损机制的影响。结果表明:陶瓷Al2O3与高铬铸铁基体之间具有良好的界面结合,复合材料的摩擦系数随摩擦频率和载荷的变化保持稳定,耐磨性远优于高铬铸铁,而且随着摩擦频率和载荷的增加,Al2O3陶瓷/高铬铸铁复合材料的抗磨损性能明显提高,这是由于复合材料中Al2O3与高铬铸铁相之间三维空间结构和良好的界面结合有利于摩擦载荷的传递;三维Al2O3陶瓷骨架在磨损表面形成硬的网络突体并起承载作用,能有效保护金属基体;磨损机制为氧化磨损及磨粒磨损共同作用。  相似文献   

5.
近年来,陶瓷颗粒非均匀分布增强钢铁基复合材料(构型复合材料)由于具有优异的耐磨性,成为国内外高性能耐磨材料研究和应用的热点.对构型复合材料耐磨性的研究进行了综述,认为在无冲击磨料磨损工况下,构型复合材料的耐磨性显著高于常规陶瓷颗粒均匀分布增强复合材料,其耐磨性顺序按照基体排列为:高铬铸铁基>合金钢基>高锰钢基复合材料;陶瓷/钢铁界面结合强,则复合材料耐磨性高;按照陶瓷颗粒排序是:WC>(TiC,ZTA)>Al2O3增强复合材料;ZTA中ZrO2含量高,则耐磨性好.在高冲击磨料磨损工况下,构型复合材料耐磨性远不如无冲击工况下的耐磨性,有的甚至比基体差;合金钢基复合材料耐磨性比高锰钢基稍高.综述了不同工况下构型复合材料的磨损机理,并提出了构型陶瓷/钢铁复合材料的研究方向.  相似文献   

6.
以晶化的硅酸铝短纤维(Al2O3-SiO2 sf为增强体、用磷酸铝为预制体粘结剂,通过挤压浸渗工艺制备了(Al2O3-SiO2sf /AZ91D镁基复合材料。通过光学显微镜、TEM和HREM分析研究了复合材料的界面微观结构和界面反应产物。结果表明:用挤压浸渗法制备的硅酸铝短纤维增强AZ91D镁基复合材料的界面厚度约为100 nm,界面上除有一定数量的MgO颗粒和少量的MgAl2O4和Mg2Si颗粒外, 还有少量的MgP4等反应产物存在;硅酸铝增强纤维与镁合金基体之间形成了较强界面结合,界面微观结构比较理想。力学性能测试表明,与AZ91D基体合金相比,复合材料的室温抗拉强度提高了约18%,弹性模量提高了约58%。  相似文献   

7.
陶瓷颗粒增强镍合金复合涂层冲蚀磨损的试验研究   总被引:2,自引:0,他引:2       下载免费PDF全文
以WC,ZrO2,Cr2O3和Al2O3陶瓷颗粒为增强相,镍合金粉末为基体,运用等离子喷涂技术制备四种陶瓷/镍合金复合涂层。采用冲蚀磨损试验机和正交试验方法,进行陶瓷颗粒相浓度、磨粒粒度、冲蚀角和速度对陶瓷颗粒/镍合金复合涂层抗冲蚀磨损性能影响的试验研究。采用表面形状测量仪对陶瓷颗粒/镍合金复合涂层磨损表面形貌进行测量和分析。试验结果得到WC,ZrO2,Cr2O3和Al2O3四种陶瓷颗粒/镍合金复合涂层冲蚀磨损率的经验关联式。  相似文献   

8.
SiCP/AZ80镁基复合材料的界面与断口特征   总被引:12,自引:2,他引:10       下载免费PDF全文
本文用SEM,TEM研究了SiC颗粒增强AZ80镁合金复合材料的界面结构和断口形貌。结果表明,SiC颗粒与镁合金界面结合紧密,没有发生界面化学反应,但在界面处可以观察到Mg17Al12共晶相在SiC表面形核生长。对复合材料断口观察表明,SiC颗粒与镁合金界面之间的粘结强度大于基体的撕裂强度,SiC颗粒的聚集、团聚是导致复合材料断裂的主要原因,且复合材料的断裂形式趋向脆性断裂。  相似文献   

9.
根据Si3N4 颗粒增强体的结构特点及等温化学气相法( ICVI) 的工艺特点, 对Si3N4 颗粒增强Si3N4 复合材料的致密化过程进行了数值模拟。用球形孔隙模型表征Si3N4 颗粒增强体的结构特征, 用传质连续方程表征先驱体在预制体中的浓度分布。为了检验模型的准确性和适用性, 进行了相应的实验验证。模拟结果与实验结果具有相似的致密化规律, 预测的渗透时间和孔隙率与实验结果均十分接近, 表明本文中建立的数学模型可以较好地表征Si3N4P / Si3N4 复合材料的ICVI 过程。  相似文献   

10.
分别用苯乙烯和丙烯酸乙酯对纳米SiO2进行辐照接枝聚合改性,通过两步熔融共混工艺与聚丙烯(PP)共混制备了SiO2/PP复合材料。研究了SiO2添加量和表面接枝不同聚合物的SiO2对复合材料力学性能的影响。结果表明,接枝改性的SiO2对PP有较好的增强增韧效果;拉伸断面观察显示复合材料韧性的提高主要由基体剪切屈服所致。对断面上个别较大团聚体分析发现,经辐照接枝聚合改性的纳米粒子团聚体的结构变得更加紧凑、结实,且随粒子表面聚合物的性质不同,团聚体与基体树脂的界面粘结也随之不同,导致其拉伸破坏形状有所差异,但与基体树脂的界面粘结都得到较好的改善。  相似文献   

11.
Abstract

The presence of carbide particles in metal matrix composites improves abrasive wear resistance properties. Abrasive wear characteristics of TiC reinforced cast iron composites have been investigated. The TiC particle size and distribution influence the wear properties of the composites. TiC reinforced cast iron composites possess better wear resistance properties than those of chromium cast irons with and without nitrogen.  相似文献   

12.
采用高能球磨和真空烧结的方法制备TiC增强高铬铸铁(HCCI)基复合材料。利用SEM,DSC等方法对不同球磨时间的粉末进行分析,研究不同烧结温度对高铬铸铁基复合材料的显微组织、硬度及密度的影响,比较相同工艺下复合材料与高铬铸铁材料的耐磨性。结果表明:球磨12 h后的粉末颗粒大小趋于稳定,粉末活性提高,烧结性能改善,烧结试样中TiC均匀地分布在基体中。随着烧结温度的升高,复合材料内部晶粒逐渐长大,密度和硬度逐渐提高。在1280℃超固相线液相烧结的条件下烧结2 h后,致密度达94.17%,硬度和抗弯强度分别为49.2HRC和980 MPa。在销盘磨损实验中复合材料的耐磨性为单一高铬铸铁材料的1.52倍,磨损机制为磨粒磨损+轻微氧化磨损。  相似文献   

13.
FeTi, B2O3, Al, and FeW particulates, approximately 40–60 μm in size, were mixed in stoichiometric ratio and sintered at 1,200 °C. The sintered particulates were added as 5 wt% to molten high chromium white cast iron over 50 C-deg above the melting temperature, and stirred at 1,000 rpm. The samples were investigated in three groups: (1) high Cr white cast iron inoculated by the particulates sintered from Al–FeTi–B2O3 particulates; (2) high Cr white cast iron inoculated by the sintered particulates derived from Al–FeTi, B2O3, and FeW particulates; and (3) specimens of the second group that were subsequently homogenized. The microhardness of ceramic particulates was measured as 2,800–3,400 HV10. The effect of sintered particulate volume fraction on the abrasive wear resistance of the high chromium white cast iron was determined. The wear resistance and hardness of the composites improved significantly as a result of particulate inoculation. The application of the homogenization heat treatment to the inoculated samples produced a microstructure having homogeneously distributed particulates.  相似文献   

14.
In this work, in situ synthesis with infiltration casting and subsequent heat treatment was applied to fabricate vanadium carbide (V8C7) particulate-reinforced iron matrix composites. The microstructure and wear-resistance of V8C7 particulate-reinforced iron matrix composites with different volume fraction were studied using scanning electron microscopy, X-ray diffraction, and wear testing. The V8C7 particles were uniformly distributed in the matrix, and the size of the V8C7 reinforcement was 2–12 μm. The relative wear resistance of the composites initially increases decreases with higher V8C7 volume fractions. The best wear resistance of the composites was 21.2 times higher than that of gray cast iron under a 20 N load. This was achieved at 24% V8C7 volume fraction. Wear of the composites manifests as grooves, broken carbide particles, and re-embedment of wear debris.  相似文献   

15.
In order to solve the cast-infiltration difficulty and low interface bonding strength of ZrO2-toughened Al2O3 (ZTA) powders reinforced high manganese steel (HMS) matrix composite, uniform and continuous Ni-encapsulated ZTA powders (ZTAp@Ni) as reinforced phase are fabricated by electroless deposition assisted with ionic liquid additive. The effects of Ethaline concentration, temperature, ZTA concentration and deposition times on the morphology of ZTAp@Ni have been investigated. Experimental results show that the thickness of Ni coating is about 7–10 μm, and there is no casting crack or shrink on the composite, so compact bonding between ceramic and matrix is obtained. In addition, the impact abrasive wear resistance testing demonstrates that the performance of ZTAp@Ni reinforced HMS composite is superior to that of matrix. On the basis of experimental analysis, a schematic illustration of the cast-infiltration process is put forward. It implies that Ni-encapsulated ZTA can be wetted with molten HMS matrix to form a ZTA/Al2NiO4-Al2MnO4/Fe interface layer through Ni diffusion and reactive wetting. The interdiffusion of Ni and other elements at ZTA interface layer can reinforce the interfacial bonding strength to form an interface layer between metal and hard phases.  相似文献   

16.
To attain a wear‐resistant material compatible with high hardness and high toughness, Hadfield steel matrix was reinforced by oriented high chromium cast iron bars, through inserting high chromium alloys flux‐cored welding wires into Hadfield steel melt at 1500 ± 10 °C. The obtained composites were investigated by XRD, SEM, micro‐hardness, three‐body abrasion wear and impact toughness testers. The results show that the alloy powders inside the flux‐cored welding wires can be melted by the heat capacity of Hadfield steel melt and in situ solidified into high chromium cast iron bar reinforcements tightly embedded in the matrix. The micro‐hardness of reinforcements of the water‐quenched composite is about four times higher than that of the matrix. The impact toughness of the water‐quenched composite is higher than that of the as‐cast composite and lower than that of Hadfield steel, and its fracture mechanism is very complicated and refers to brittle and ductile mixture fracture mode. The excellent impact toughness and better wear resistance of the water‐quenched composite are attributed to combine fully the advantages and avoid the drawbacks of both Hadfield steel and high chromium cast iron. Additionally, in industrial application, the pulverizer plate produced by this composite, has also better wear resistance compared to the reference Hadfield steel pulverizer plate.  相似文献   

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