-NCO含量对聚氨酯/陶瓷复合材料冲蚀磨损性能的影响

用聚四氢呋喃醚二醇（PTMG）与甲苯二异氰酸酯（TDI）反应,再与陶瓷粉末进行共混,制得耐磨蚀聚氨酯复合材料.用相对抗冲蚀磨损性法评价了聚氨酯陶瓷复合材料的耐磨性,通过扫描电镜观察了聚氨酯复合材料的磨损形貌,尝试解释了陶瓷颗粒增强聚氨酯弹性体的抗冲蚀磨损机制.试验表明：当-NCO含量为6.35%、Si3N4粉末质量分数为10%时,耐磨性能最好,可提高纯聚氨酯弹性体抗冲蚀磨损性能近2倍.     

聚氨酯陶瓷复合材料的抗冲蚀磨损性能研究

用聚四氢呋喃醚二醇和甲苯二异氰酸酯反应后，与陶瓷粉末进行共混，制得抗冲蚀磨损的聚氨酯复合材料。用相对抗冲蚀磨损性法评价了聚氨酯陶瓷复合材料的耐磨性，通过扫描电镜观察了聚氨酯复合材料的磨损形貌，解释了微米级陶瓷粉末增强聚氨酯的抗冲蚀磨损性能机理。结果表明，Si3N4粉末质量分数在5％～10％时，复合材料抗冲蚀磨损性能是聚氨酯的1．87倍，TiN聚氨酯复合材料抗冲蚀磨损性能是聚氨酯的2．81倍。     

聚氨酯/TiO2纳米复合材料冲蚀磨损特性研究

以纳米TiO2作为填料,制备耐磨蚀聚氨酯纳米复合材料.用相对抗磨损性法评价了聚氨酯纳米复合材料的冲蚀磨损性,通过扫描电镜观察聚氨酯纳米复合材料的磨损形貌,尝试解释纳米TiO2增强聚氨酯复合材料抗含沙冲蚀磨损性能的机理.试验结果表明,纳米粒子均匀分散于聚氨酯中,使聚氨酯弹性体耐磨蚀性得以提高.聚氨酯/TiO2纳米复合材料的抗冲蚀磨损性能分别是45#钢的10.67倍,2Cr13钢的6倍,纯聚氨酯的1.28倍,TiN/聚氨酯复合材料的1.09倍.     

压渗法制备陶瓷网络复合材料摩擦行为研究

提出了三维陶瓷网络(骨架)增强金属基复合材料的新构思,设计和制备了一种新型的三维陶瓷网络(骨架)增强铝合金复合材料,研究了其在干摩擦状态下的滑动摩擦磨损行为。结果表明,基体铝合金在重载时产生严重粘着磨损,磨损层发生软化和塑性流动,而复合材料中的陶瓷颗粒暴露于磨损表面并起承载作用,从而保护基体小发生严重磨损。与基体合金相比,复合材料摩擦因数平稳而较低,且耐磨性提高6倍左右。     

钢纤维和硅酸铝纤维混杂增强陶瓷基复合材料的摩擦磨损性能

利用热压烧结法制备了钢纤维和硅酸铝纤维混杂增强陶瓷基复合材料,探讨了硅酸铝纤维含量对该复合材料摩擦磨损性能的影响,借助扫描电子显微镜(SEM)观察了复合材料的磨损表面形貌,并分析了其磨损机理。结果表明:随硅酸铝纤维含量的增加,复合材料的摩擦因数增大;高温下复合材料的耐磨性能随硅酸铝纤维含量的增大而降低;未添加硅酸铝纤维复合材料的磨损形式主要表现为脆性脱落和疲劳磨损,并伴有磨粒磨损;添加了硅酸铝纤维的陶瓷基摩擦材料的磨损形式均以粘着磨损为主。     

三元硼化物强化粉末高速钢的摩擦磨损特性研究

采用反应硼化烧结法在1193℃下真空烧结,成功制备出具有良好耐磨性的粉末高速钢与三元硼化物陶瓷的复合材料;在自制摩擦磨损试验机上进行了摩擦磨损实验.分析表明:复合材料主要由三元硼化物基硬质相和高速钢基体组成,陶瓷颗粒与基体界面结合良好,分散均匀,耐磨性能良好.     

SiC含量对注射成形SiC_p/Cu复合材料磨损性能的影响

采用粉末注射成形技术制备出了SiC_p/Cu复合材料,研究了SiC含量对其磨损率的影响,并对磨损机理进行了分析。结果表明:随着复合材料中SiC含量的增多,其磨损率减小;在SiC含量(体积分数)为3%和6%时,主要以粘着磨损为主,随SiC含量增多,粘着磨损减弱,磨粒磨损逐渐增强,在SiC含量为9%时,已转化为以磨粒磨损为主,在SiC含量为12%时,粘着磨损已不明显,基本为磨粒磨损,同时摩擦表面形成了一层较致密的机械混合层。     

二硫化钼对PA6-PU嵌段共聚物复合材料摩擦磨损性能的影响

利用浇铸工艺制备二硫化钼(Mo S2)改性聚酰胺6-聚氨酯(PA6-PU)嵌段共聚物的复合材料,研究在不同载荷和滑动速度下Mo S2对复合材料的摩擦磨损性能的影响;用扫描电子显微镜(SEM)观察复合材料的磨损面,探讨其磨损机制。结果表明:低转速和低载荷下,Mo S2的添加对复合材料的摩擦性能的改善不明显,反而使复合材料的磨损急剧增加;而在高载荷和高转速下,随Mo S2含量增加,Mo S2能在复合材料表面形成有效的转移膜,改善复合材料摩擦磨损性能。在Mo S2含量较低时,复合材料的磨损机制以黏着磨损为主,随着Mo S2含量的增加,复合材料的磨损机制转变为黏着磨损伴随着磨粒磨损。     

陶瓷粉末选择性激光烧结及聚合物纳米复合材料的研究现状及前景

介绍选择性激光烧结技术(SLS)的原理、特点。评述国内外选择性激光烧结普通陶瓷粉末、纳米陶瓷粉末及聚合物纳米复合材料的研究进展,并对以后的研究方向提出建议。     

WC-Al2O3复合材料与Si3N4陶瓷和YG6硬质合金配副时的摩擦磨损行为

采用真空热压烧结技术制备了WC-15%Al_2O_3(质量分数)复合材料,分别以Si_3N_4陶瓷和YG6硬质合金为配副,在载荷40,80N下进行了干滑动摩擦磨损试验,研究了复合材料的摩擦磨损性能。结果表明:与Si_3N_4陶瓷配副时复合材料的摩擦因数较高且波动较大,与YG6硬质合金配副时摩擦因数较低且相对稳定;与Si_3N_4陶瓷配副时,复合材料的磨损率在较低载荷下高于与YG6硬质合金配副时的,在较高载荷下则低于与YG6硬质合金配副时的;在载荷40,80N下,复合材料的磨损机制均主要为疲劳磨损,伴随着微裂纹、脆性断裂和晶粒拔出等特征。     

The erosive wear behavior of basalt based glass and glass–ceramic coatings

In this study, the effects of impact angle and SiC reinforcement on the erosion wear behavior of basalt base glass and glass–ceramic coatings were investigated. Basalt powders with 0–50% SiC additions were coated on AISI 1040 steel by atmospheric plasma spray coating technique. Controlled heat treatment was applied to amorphous basalt base coatings for glass–ceramic transformation. Erosion tests were realized by using corundum media at the different impact angles and velocities. Wear test results showed that the SiC addition in the basalt based coatings resulted in increase erosive wear resistance of glass and glass–ceramic coatings.     

Characterization and prediction of abrasive wear of powder composite materials

Composite materials produced by powder metallurgy provide a solution in many engineering applications where materials with high abrasion and erosion resistance are required. The actual wear behaviour of the material is associated with many external factors (particle size, velocity, angularity, etc.) and intrinsic material properties (hardness, toughness, Young modulus, etc.). Hardness and toughness properties of such tribomaterials are highly dependent from the content of reinforcing phase, its size and from the mechanical properties of the constituent phases. In this study an attempt is made to model the erosion wear behaviour of composite materials, to calculate the wear rate and to correlate erosion rates with experimental results and material parameters. Powder composites cermets and metal-matrix composite materials reinforced with different content of hard phase were used as examples in this research. Wear mechanisms of materials were investigated. Following from the main mechanisms of erosion wear the models of plastic deformation and brittle fracture are developed for prediction of erosion of powder composite materials. It was demonstrated, that the erosion rate of hardmetal-type materials can be predicted using the results obtained by microindentation methods. The use of hardness distribution parameters is justified with materials with low binder content.     

纳米氧化镍/锌复合材料的制备及在热浸镀中的应用

用高能球磨法制备了纳米氧化镍/锌复合粉末,然后通过真空热压法将其制成块体复合材料,并熔化于锌液中,在45钢基片上进行热浸镀;用XRD、TEM、FESEM和EDS等对复合粉末、块体复合材料的组织、结构进行了分析;用腐蚀失重法、冲蚀磨损法研究了镀层的耐腐蚀和耐磨损性能。结果表明:用高能球磨法制备的纳米氧化镍/锌复合粉末中,纳米氧化镍颗粒弥散均匀分布在锌颗粒上;纳米氧化镍颗粒的加入能显著提高镀层的耐磨性能,而对耐腐蚀性能影响不大。     

Al_2O_3基陶瓷拉丝模材料的摩擦磨损性能

采用热压法制备出三种Al2O3基复合陶瓷材料,用于陶瓷拉丝模的制作。计算出拉丝模在拉拔加工中的应力分布,指出拉丝模应力最大和磨损最严重的区域。陶瓷拉丝模的摩擦磨损特性是影响拉丝模工作寿命的主要原因,因此在MRH-3高速环块磨损试验机上对Al2O3基复合陶瓷材料摩擦磨损行为及其磨损机理作了试验研究。测试出Al2O3基复合陶瓷材料在不同转速和载荷下,摩擦因数和磨损率的变化规律。通过扫描电镜观测其磨损区微观形貌,分析其滑动摩擦的微观机理为机械磨损耕犁、粘着和脆性微脱落。结果表明,这三种Al2O3基复合陶瓷拉丝模材料具有较高抗弯强度和断裂韧度。Al2O3基复合陶瓷材料的磨损机理主要是脆性脱落和耕犁,具有良好的耐磨性,是制备拉丝模的优良材料。     

Tribological studies of polymer based ceramic–metal composites processed at ambient temperature

Use of composite material is increasing due to economical processing of complicated shapes in large quantities. Addition of fiber/particulates improves the composite strength. In the current study, the tribological characterization of polymer based particulate composites which are processed at room temperature are investigated. The friction and wear behavior of polystyrene reinforced with steel powder (polymer–metal), alumina powder (polymer–ceramic) and a mix of steel and alumina powders (polymer–metal–ceramic) have been investigated under dry sliding conditions using a pin-on-disc tribometer. Tests were conducted at different normal loads and sliding velocities at room temperature. Coefficient of friction and wear loss during the wear tests are determined. Presence of metal and ceramic particulates affects the tribological behavior of the composite. The rise in temperature of the pin during sliding was measured. The rise in contact temperature is influenced by the composition which in turn influences the wear behaviour. The polymer–ceramic composite exhibits the lowest wear rate among the materials investigated.     

The effect of various metallic filling materials on the wear resistance of aromatic-polyamide-based composite materials

The tribological properties of metal-containing composite materials have been studied. The effect of filling materials on the composite materials’ thermal diffusivity and physical and mechanical properties has been established. It has been shown that the introduction of fine metal powders into phenylone, a heat-resistant polyamide, considerably enhances the wear resistance of phenylone. It has been established that the wear resistance of the developed metal-containing polymers reaches the maximum value with a content of the filling material of 15 wt %. It has been shown that the wear rate upon oil lubrication is strongly influenced by the temperature properties of the metal-containing polymers.     

Electrical and tribological properties of composite material with copper matrix reinforced by superelastic hard carbon

Electrical and tribological properties of a copper-based composite material reinforced by superelastic hard carbon particles are studied. Composite material specimens have been produced using the hightemperature pressing of mixtures of copper and fullerene powders. Electrical and tribological reciprocal tests carried out using the plane-on-plane arrangement have shown that the coefficient of friction of the composite material–Ni pair is lower than that of the reference L63 brass–Ni pair at similar values of contact electrical resistance. The abrasive wear resistance of the composite material is 40 times higher than that of brass. The developed copper-based composite materials reinforced by superelastic carbon particles hold promise for use in sliding electrical contacts.     

多种径向高压密封材料的性能测试与比较

采用间隙挤出实验和磨损实验,研究了几种高压转轴密封材料的抗间隙挤出性能和抗磨损性能。结果表明:PTFE复合材料的抗间隙挤出和抗变形性能较差,而聚酮和聚氨酯材料的较好;聚酮、超高分子聚乙烯、PTFE复合材料以及聚氨酯的耐磨性能均较好,但PTFE复合材料(PTFE聚合物复合材料除外),尤其是含青铜的PTFE复合材料,对相对旋转面的损伤严重;比较的几种密封材料中,超高分子聚乙烯具有最低的摩擦因数,但其耐高温能力最弱;聚氨酯的摩擦因数与PTFE复合材料处于同一级别。