修饰的纳米铜粒子对合成机油抗磨性能研究

分别采用不同的摩擦磨损试验机考察了DDP修饰的纳米铜粒子对合成机油摩擦磨损性能的影响。结果表明，DDP修饰的纳米铜粒子作为添加剂，提高了摩擦副的耐磨减摩性能。     

Effect of Mixed Rare Earth Fluorides on the Mechanical and Tribological Characteristics of Ni-Based Alloy

In this paper, Ni-based alloys with different addition amounts of mixed rare earth fluoride were prepared using a P/M method in an intermediate frequency inductive furnace. The effect of mixed rare earth fluoride (30.9 wt.% LaF₃ and 69.1 wt.% DyF₃ in composition) additions on the mechanical strength of the alloy was investigated and compared with that of a CeF₃ addition. The findings indicated that by adding 3 wt.% mixed rare earth fluorides the improved toughness can be obtained. By adding 3 wt.% and 5 wt.% of mixed rare earth fluorides the compressive strength at 700°C were increased. The friction and wear behavior of the composite sliding against a high temperature self-lubricating composite at room temperature and 600°C in air were investigated on a pin-on-disk tribometer. The composites showed better tribological performances at 600°C than at room temperature.     

机房建设中需要考虑的几个问题

笔者根据在机房工程方面多年的工作经验，结合现阶段机房工程的发展及国标要求，阐述了机房建设过程中（规划、设计、施工和使用）需要考虑的一些问题，对正准备建设机房或正在建设机房的单位，有较高的参考价值和可操作性。     

PtFe nanotubes/graphene hybrid: Facile synthesis and its electrochemical properties

PtFe nanotubes are synthesized by galvanic exchange reactions using Co nanowires as template and reducing agent, followed by mixed with graphene to prepare PtFe nanotubes/graphene hybrid catalyst. The morphology and crystal structure of as-made hybrid are characterized by transmission electron microscope and X-ray diffraction. Its electro-catalytic properties toward methanol oxidation are investigated by cyclic voltammetry and chronoamperometry. The average diameter and wall thickness of the PtFe nanotubes supported on graphene are ca. 50 nm and 10 nm, respectively. As an electro-catalyst for methanol electro-oxidation, PtFe nanotubes/graphene catalyst displays higher specific activity and stability than commercial PtRu/C catalyst and PtFe nanoparticles/graphene catalyst.     

Tribological Behavior of UHMWPE Reinforced with Graphene Oxide Nanosheets

In this article, a series of graphene oxide (GO)/ultrahigh molecular weight polyethylene (UHMWPE) composites are successfully fabricated through an optimized toluene-assisted mixing followed by hot-pressing. The mechanical and tribological properties of pure UHMWPE and the GO/UHMWPE composites are investigated using a micro-hardness tester and a high speed reciprocating friction testing machine. Also, the wear surfaces of GO/UHMWPE composites are observed by a scanning electron microscope (SEM), to analyze the tribological behavior of the GO/UHMWPE composites. The results show that, when the content of GO nanosheets is up to 1.0 wt%, both the hardness and wear resistance of the composites are improved significantly, while the friction coefficient increases lightly. After adding GO, the tribological behavior of the GO/UHMWPE composites transforms from fatigue wear to abrasive wear associated with the generation of a transfer layer on the contact surface, which efficiently reduced the wear rate of the GO/UHMWPE composites.     

高性能润滑材料多烷基环戊烷的研究进展

介绍高性能润滑材料多烷基环戊烷(MACs)作为基础油和边界润滑薄膜的发展概况及发展现状,阐明MACs摩擦性能优于其他润滑材料的作用机制及末端基团功能化、添加纳米颗粒、表面织构化、构筑双层薄膜等改善MACs摩擦学性能的方法途径及机制,指出当前MACs作为高性能润滑材料存在的问题及将来的研究趋势。     

Ultra-High Tribological Performance of Magnetron Sputtered a-C:H Films in Sand-Dust Environment

The hydrogenated amorphous carbon (a-C:H) films were prepared on AISI 440C steel substrates using a RF magnetron sputtering graphite target in the CH₄ and Ar mixture atmosphere. The friction and wear behavior of a-C:H films were comparatively investigated by pin-on-disc tester under dry sliding and simulated sand-dust wear conditions. In addition, the effects of applied load, amount of sand and sand particle sizes on the tribological performance of a-C:H films were systemically studied. Results show that a-C:H films exhibited ultra-high tribological performance with low friction coefficient and ultra-low wear rate under sand-dust environments. It is very interesting to observe that the friction coefficient of a-C:H film under sand-dust conditions was relatively lower when compared with dry sliding condition, and the wear rate under sand-dust conditions kept at the same order of magnitude (×10⁻¹⁹ m³/N m) with the increase of applied load and particle size as a comparison with the dry sliding condition. Based on the formation of “ridge” layer (composite transfer layer), a transfer layer-hardening composite model was established to explain the anti-wear mechanisms and friction-reducing capacity of a-C:H solid lubrication films under sand-dust conditions.     

Fabrication of bulk Al2O3 dispersed ultrafine-grained Cu matrix composite by self-propagating high-temperature synthesis casting route

Bulk Al₂O₃ dispersed ultrafine-grained (UFG) Cu matrix composite has been fabricated by self-propagating high-temperature synthesis (SHS) casting route. The microstructures and mechanical properties of the as-fabricated materials have been investigated by scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis, and microhardness measurements and compression tests, respectively. The results show that the as-fabricated material has small amount of entrapped Al₂O₃ particles in uniform microstructure Cu having a grain size ranging from 200-500 nm with an elevated compressive yield stress (298 MPa) and an improved microhardness value (1.06 GPa). The possible strengthening mechanism of the product has been discussed.     

端羟基聚二甲基硅氧烷／蓖麻油改性聚氨酯嵌段共聚物的研究

研究了端羟基的聚二甲基硅氧烷醇解蓖麻油改性聚氨酯预聚体共混改性。共聚物成膜后，分子结构中的有机硅链段更颂更倾向于表面聚集取向，而聚氨酯链段朝向内层。     

GCr15轴承钢N＋B离子注入层的XRD,AES和XPS研究

用X-射线衍射(XRD)、俄歇电子能谱(AES)和X-光电子能谱(XPS)的方法对N+B离子注入层的相组成、元素的分布和元素的结合状态进行了综合考察。结果表明:注入层是由基体中原有的α-Fe、Fe_3C相和注入过程中新生成的六方BN相和ε-Fe_2N-Fe_3N相组成的。另外,在注入层表面还有一层石墨型结构的碳膜存在。