SiC颗粒增强PTFE基复合材料摩擦磨损特性研究

利用冷压烧结法制备了不同含量的SiC颗粒填充聚四氟乙烯(PTFE)复合材料，采用M-200环块试验机进行摩擦磨损试验，研究了SiC颗粒增强PTFE基复合材料在干摩擦条件下的磨损特性，并利用扫描电子显微镜对复合材料的磨损表面形貌进行了观察，对复合材料的磨损机制进行了分析．结果表明：SiC颗粒增强复合材料的耐磨性能显著提高，但其摩擦系数有所增大；随SiC颗粒含量的增加复合材料的磨损机理由粘着磨损占主导逐渐转变为显微切削占主导；复合材料中增强相SiC颗粒有3种流失形式：整体脱落、磨损、碎裂．     

颗粒增强纯铝基复合材料的磨损特性

研究了Ａｌ２Ｏ３及ＳｉＣ颗粒增强纯铝基复合材料的磨损特性，结果表明，Ａｌ２Ｏ３或ＳｉＣ颗粒的加入，提高了复合材料的耐磨粒磨损性能，随着颗粒含量的增加，复合材料的耐磨性增大；ＳｉＣ与Ａｌ２Ｏ３复合材料的耐磨性相近；复合材料孔隙率较大时耐磨性降低；复合材料的耐磨性不随硬度升高而增加；颗粒增强纯铝基复合材料干摩擦的磨损机理以磨粒磨损为主；润滑摩擦的磨损机理为氧化磨损．     

SiC颗粒填充PTFE复合材料耐磨性能的研究

利用M－200型环一块大材料磨损试验机，对机械混合法制备的SiC陶瓷颗粒填充聚四氟乙烯（PTFE）复合材料在干摩擦条件下的磨损特性进行了研究，并利用扫描电子显微镜(SEM)对TFE复合材料的磨损表面形貌进行了观察。结果表明SiC颗粒入大大提高了PTFE的耐磨性能，颗粒的添加量、磨损载荷、磨损温度影响复合材料耐磨性能的重要因素。     

纳米Si3N4颗粒填充铸型尼龙的摩擦学性能研究

为了研究纳米Si3N4颗粒作为填料对铸型尼龙（MC尼龙）的摩擦磨损性能的影响，选用两种复合材料在MM－200摩擦磨损试验机上进行了试验研究，并借助于扫描电镜观察了磨损形貌，探讨了磨损机理，研究结果表明，在干摩擦条件下，Si3N4颗粒填MC尼龙与钢环对摩的摩擦数随载荷的升高而降低，在相同载荷时均高于纯尼龙，在一定的滑动速度下，Si3N4颗粒填充MC尼龙的耐磨性能与载荷大小有关，当载荷较低时，复合材料的耐磨性能比纯尼龙好，其磨损机理主要是磨粒磨损和粘着磨损，当载荷较高时，复合材料的耐磨性能不如纯尼龙，其磨损机理主要是疲劳剥落，并有磨粒磨损和粘着磨损。     

纳米氧化铝颗粒增强铜-碳基复合材料的磨损性能

用MA技术制备了C体积分数为10%的Cu-C固溶体粉体,用溶胶-凝胶(sol-gel)烧结技术制备了平均尺寸为12 nm的γ-Al2O3颗粒和用SPS方法制备了纳米Al2O3颗粒增强Cu-C固溶体基复合材料。采用X射线衍射仪对MA粉体、干凝胶和煅烧粉体进行了物相分析;通过JSM-5500LV型扫描电镜对磨损表面形貌进行观察分析并分析其磨损机制;使用MG-2000型高温摩擦磨损试验机对制备的复合材料进行了干摩擦实验并测定其磨损量。结果表明:纳米氧化铝颗粒体积分数及磨损载荷对复合材料摩擦磨损特性有显著影响,纳米氧化铝的体积分数从0%增加到2%,Cu基复合材料的磨损量从6.2 mg降到2.1 mg。     

硬质合金涂层刀具铣削SiCp/Al复合材料刀具磨损研究

SiCp/Al复合材料因含有大量SiC硬质颗粒而使其切削加工性较差。针对该材料的高速高效加工问题,利用硬质合金涂层刀具对体积分数为20%的SiCp/Al复合材料进行面铣,通过单因素实验,研究了切削速度、进给量和轴向切削深度对刀具前刀面和后刀面的磨损过程的影响,以及刀具磨损萌生、扩展演化规律。结果表明:在硬质合金涂层刀具精加工SiCp/Al复合材料过程中,刀尖与工件表面的接触先是凸圆弧面接触,然后变成凹圆弧面接触,最后变成平面接触;刀具磨损随切削速度和轴向切深的增大而增大,而随进给量的增大而减小;硬质合金涂层刀具失效的原因主要是后刀面的耕犁磨损,后刀面最大磨损量VB_(max)超过了0.6 mm,而后刀面磨损的主要原因是磨粒磨损和涂层剥落。     

电沉积SiC颗粒增强抗磨复合材料研究

采用电刷镀技术制取了Ｎｉ－Ｗ－Ｃｏ／ＳｉＣ颗粒增强抗磨复合材料,分析了ＳｉＣ颗粒沉积量的影响因素,并研究了复合材料的磨损特性,实验结果表明,复合材料具有较高的硬度和耐磨性。     

超声振动高速铣削SiCp/Al复合材料的切削力及刀具磨损特性

颗粒增强铝基复合材料由于其优异的性能,在航空、航天及军事等领域得到广泛应用,但材料的难加工特性限制其进一步应用.采用超声高速铣削对高体分SiC颗粒增强铝基复合材料进行了实验研究,研究了超声切削参数对铣削力的影响,分析了超声加工时的刀具磨损情况和机理.研究发现采用超声铣削可以有效地减小切削力,得出了超声加工SiC颗粒增强铝基复合材料的合理切削用量.同时,超声铣削很大程度上降低了磨料磨损和粘结磨损,提高了刀具的使用寿命.     

原位合成TiC/Fe基复合材料的组织结构和磨损性能

利用粉末冶金技术,在真空状态下使Fe-Ti-C体系进行碳化反应原位合成TiC/Fe基复合材料,用扫描电镜(SEM)、X射线衍射(XRD)分析复合材料的组织结构和相组成,用热分析法和高温X射线衍射研究Fe-Ti-C体系原位合成的反应机理,用MM-200磨损试验机对复合材料进行耐磨性实验.研究结果表明,反应合成的复合材料主要相组成为TiC、α-Fe和Fe3C,所合成的硬质相TiC颗粒细小,在铁基体中均匀分布.三元体系Fe-Ti-C的反应机理为,首先在765.6 ℃发生Fe的同素异构转变,即α-Feγ-Fe;其次在1078.4 ℃,Ti与Fe共熔而形成低共熔体Fe2Ti;最后在1138.2 ℃,C与Fe2Ti反应生成TiC.在重载干滑动磨损条件下此复合材料显示了很好的耐磨性能.     

石墨铝复合材料的研制及摩擦磨损

本文叙述了一种制备共晶型铝硅合金-石墨颗粒复合材料的方法,即采用盐溶液对石墨颗粒进行预处理。通过液体旋涡技术将石墨颗粒加入到共晶型铝硅合金中;对石墨铝复合材料在无润滑条件下的磨损特性进行了研究,探讨了法向载荷、滑动速度及复合材料中的石墨含量对石墨铝复合材料摩擦系数和磨损速率的影响。     

Microstructure and wear resistance of in situ NbC particles reinforced Ni-based alloy composite coating by laser cladding

The in situ synthesized NbC particles reinforced Ni-based alloy composite coating was produced by laser cladding a precursor mixture of Ni-based alloy powder,graphite and niobium powders on a steel substrate.The microstructure,phase composition and wear property of the composite coating were investigated by means of scanning electron microscopy(SEM),X-ray diffraction(XRD)and dry sliding wear test.The experiment results show that the composite coating is homogeneous and free from cracks,and about 0.8 mm thick.The microstructure of the composite coating is mainly composed of NbC particles,CrB type chromium borides,γ-Ni primary dendrites,and interdendritic eutectics.CrB phases often nucleate and grow on the surface of NbC particles or in their close vicinity.NbC particles are formed via in situ reaction between niobium and graphite in the molten pool during the laser cladding process and they are commonly precipitated in three kinds of morphologies,such as quadrangle,cluster,and flower-like shape.Compared with the pure Ni-based alloy coating,the microhardness of the composite coating is increased about 38%,giving a high average hardness of HV0.21000,and the wear rate of the composite coating is decreased by about 32%,respectively.These are attributed to the presence of in situ synthesized NbC particles and their well distribution in the coating.     

Wear Behavior of In-situ TiC Particles Reinforced Aluminum Matrix Composite

The microstructure, tensile property and wear resistance of 7075 aluminum matrix composite reinforced with TiC particles prepared by in-situ reaction casting were investigated. The effect of TiC reinforcement on wear behavior was analyzed. The wear mechanism was also discussed. A micro-mechanism model of reaction kinetics for synthesis of TiC was acquired. Results show that TiC could increase the tensile and yield strength, but decrease the elongation. Besides, TiC particles improve the property of wear resistance of 7075 aluminum alloy. The wear mechanisms include abrasive wear and adhesive wear in wear test process.     

Effect of attapulgite added in plating bath on the properties of Ni/TiC nano-composite coatings

Pure copper plates were coated by Ni-TiC dipulse current plating method. The effects of adding different concentration(ranging from 0.5 g/L to 3.0 g/L) of attapulgite nano particles to the plating bath on the surface morphology, wear resistance, and oxidation resistance of Ni/TiC/Attapulgite nano-composite coatings were investigated. The experimental results show that the composite coating is flat and compact with adding 3.0 g/L in the bath, and the coating preferred orientation is changed from the planes (111) to (200). The coefficient of the composite coatings decreases from 0.68 to 0.18 with increasing content of attapulgite in the bath, a mixed mode of adhesive-abrasive wear occurs for all coatings, and the wear mechanism shows a transition from adhesive-abrasive to predominantly abrasive wear mechanism when the concentration of attapulgite is beyond 1.5 g/L in electrolyte. The oxidation resistance of composite coatings is the best prepared when adding attapulgite particles at 0.5 g/L in the bath, the oxide mainly consists of a NiO phase by X-ray analysis.     

分散方式对Ni-Si_3N_4纳米复合电镀层显微组织和性能的影响

采用超声波分散加机械搅拌技术在纯铜板上制备了含有纳米Si3N4颗粒的镍基纳米复合镀层,研究了分散方式对复合镀层中纳米颗粒含量、复合镀层组织结构、显微硬度和磨损性能的影响。利用扫描电镜(SEM)和X-射线衍射仪(XRD)分析了镀层表面的显微组织及相结构,通过磨损实验机检测了复合镀层的耐磨性能。结果表明,采用超声波分散技术可获得组织细密、高显微硬度的纳米复合镀层,其显微硬度最高可达996 HV,耐磨性能较未经超声波分散处理的镀层有显著提高。     

玻璃微珠改性PTFE的制备及性能研究

研究了玻璃微珠改性PTFE复合材料的布氏硬度、压缩强度、冲击强度及摩擦、磨损性能，并借助SEM探讨了冲击断面和磨损表面的微观形态结构，对各影响因素进行了机理分析。结果表明：加入适量的玻璃微珠可以提高复合材料的硬度及抗压强度及耐磨性能；但由于存在相界面缺陷，复合材料的冲击强度降低；随着玻璃微珠质量含量的增加，磨损机理发生变化：由粘着磨损逐渐转变为磨粒磨损，摩擦系数有所增大。     

Wear behavior of <Emphasis Type="Italic">in-situ</Emphasis> TiC particles reinforced aluminum matrix composite

The microstructure, tensile property and wear resistance of 7075 aluminum matrix composite reinforced with TiC particles prepared by in-situ reaction casting were investigated. The effect of TiC reinforcement on wear behavior was analyzed. The wear mechanism was also discussed. A micro-mechanism model of reaction kinetics for synthesis of TiC was acquired. Results show that TiC could increase the tensile and yield strength, but decrease the elongation. Besides, TiC particles improve the property of wear resistance of 7075 aluminum alloy. The wear mechanisms include abrasive wear and adhesive wear in wear test process.