稀土化合物增强ZA—27合金耐磨性的研究

对稀土化合物增强ＺＡ－２７合金的组织及耐磨性做了研究。试验发现,由于在ＺＡ－２７合金中加入一定量的ＥＲ和Ｓｉ元素,组织中出现一些颗粒状第二相;这些物相分布在晶界及枝晶间,阻止了晶粒长大。通过航向电镜能谱分析发现,该物相是一种含有Ｚｎ、Ａｌ、Ｓｉ及ＲＥ元素的复杂化合物。经测试,这种物相的显微硬度要比基体高得多。耐磨性等性能试验结果表明,这种合金的耐磨性要比ＺＡ－２７合金高４倍,比Ｓｉ相增强合金也高,     

干粉合成中氟离子对ZSM—5沸石的结构定向作用

考察了Ｎａ２Ｏ－ＳｉＯ２－Ａｌ２Ｏ３－ＥＤＡ干粉体系中是否加入ＮａＦ以及加入量对产品物相及结晶度的影响。结果表明,当反应体系不加ＮａＦ时,产物为结晶度高的单一晶相的ＺＳＭ－３５沸石,而体系中加入ＮａＦ时,产品中有ＺＳＭ－５沸石物相出现,而且随着ＮａＦ加入量的增加,产品物相完全转化为具有很高结晶度的单一相ＺＳＭ－５沸石。说明氟离子对干粉体系中ＺＳＭ－５沸石的生成具有明显的结构定向作用     

混合稀土对ZA27合金阻尼性能的影响

研究了ＺＡ２７合金的稀土变质机制及阻尼性能,利用悬臂梁测试了阻尼能力。结果表明,合金中加入Ａｌ－１０％ＲＥ中间合金可以细化组织和提高阻尼能力,稀土添加量为０．３％时有最佳的变质效果和最佳高的阻尼能力。     

LEWIS ACIDIC SITES NOT ASSOCIATED WITH EXTRA-FRAMEWORK ALUMINUM IN DEHYDROXYLATED ZEOLITE HZSM-5

ＬＥＷＩＳＡＣＩＤＩＣＳＩＴＥＳＮＯＴＡＳＳＯＣＩＡＴＥＤＷＩＴＨＥＸＴＲＡ－ＦＲＡＭＥＷＯＲＫＡＬＵＭＩＮＵＭＩＮＤＥＨＹＤＲＯＸＹＬＡＴＥＤＺＥＯＬＩＴＥＨＺＳＭ－５￥ＴｉｅＨｏｎｇＣＨＥＮ；ＰｉｎｇＣｈｕａｎＳＵＮ；ＡｉＪｕＭＥＮ；ＺｈｏｎｇＹ...     

镧对Al—Si合金锶和钠变质的影响

在含有变元素锶或钠的铸造Ａｌ－Ｓｉ－Ｃｕ－Ｍｇ合金中添加微量镧，发现合金组织中同时存在在富镧和锶的化合物，而镧和钠不存在这种作用，在富镧的化合物中没有钠的富集，因此镧对锶和钠变质存在不同程度的影响。     

杂原子B—ZSM—35沸石的干法合成,表征及CO＋H2反应性能的研究

首次利用吸附态模板剂在Ｎａ２Ｏ－ＳｉＯ２－Ｂ２Ｏ３－ＤＥＡ干粉体系中合成了杂原子Ｂ－ＳＺＭ－３５沸石，ＸＲＤ，ＳＥＭ，ＩＲ，及ＣＯ加氢反应研究了其物理化学特性。结果表明，Ｂ原子同晶取代Ａｌ原子进入ＺＳＭ－３５沸石骨加。     

镧对Al－Si合金锶和钠变质的影响

在含有变质元素锡或钠的铸造Ａｌ－Ｓｉ－Ｃｕ－Ｍｇ合金中添加微量镧，发现合金组织中同时存在富镧和银的化合物，而镧和钠不存在这种作用，在富镧的化合物中没有钠的富集，因此镧对锶和钠变质存在不同程度的影响。     

邻苯二酚作螯合剂合成全硅方钠石（Si—SOD）和全硅ZSM—5（S …

通过在两个合成分子筛的体系ＳｉＯ２－ＮａＯＨ－ＥＧ－Ｒ和ＳｉＯ２－ＴＰＡＢｒ－ＮａＯＨ－Ｈ２Ｏ－Ｒ（Ｒ：邻苯二酚,ＥＧ;乙二醇）中加入邻苯二酚获得了具有较大尺寸和完善形貌的分子筛单昌。＾２９Ｓｉ ＮＭＲ,ＩＲ和ＵＶ－Ｖｉｓ光谱表明,在反应混和物中有硅－邻苯二酚螯全物生成,这种硅的螯合物在形成分子筛大单昌过程中起到了缓释硅源的作用。     

NEW HETEROCYCLIC SYSTEM SYNTHESIS VI． THE CYCLOADDITION DERIVATIVES OF 1，5－BENZOTHIAZEPINE AND 1，5－BENZODIAZEPINE

ＥＮＥＷＨＥＴＥＲＯＣＹＣＬＩＣＳＹＳＴＥＭＳＹＮＴＨＥＳＩＳＶＩ．ＴＨＥＣＹＣＬＯＡＤＤＩＴＩＯＮＤＥＲＩＶＡＴＩＶＥＳＯＦ１，５－ＢＥＮＺＯＴＨＩＡＺＥＰＩＮＥＡＮＤ１，５－ＢＥＮＺＯＤＩＡＺＥＰＩＮＥ￥ＪｉａＸｉＸＵ；ＳｈｅｎｇＪＩＮ（Ｄｅｐａ...     

A CONVENIENT METHOD FOR SYNTHESIZING AND CHARACTERIZATION OF （Z）－ALKENOLS AND THEIR ACETATES

ＡＣＯＮＶＥＮＩＥＮＴＭＥＴＨＯＤＦＯＲＳＹＮＴＨＥＳＩＺＩＮＧＡＮＤＣＨＡＲＡＣＴＥＲＩＺＡＴＩＯＮＯＦ（Ｚ）－ＡＬＫＥＮＯＬＳＡＮＤＴＨＥＩＲＡＣＥＴＡＴＥＳ￥ＧｕＹＵＡＮ（ＤｅｐａｒｔｍｅｎｔｏｆＣｈｅｍｉｓｔｒｙ，ＰｅｋｉｎｇＵｎｉｖｅｒｓｉ...     

Influence of Carbon Black and Silica Filler on the Rheological and Mechanical Properties of Natural Rubber Compound

Rubber compounds are reinforced with fillers such as carbon black and silica. In general, filled rubber compounds shows smooth rheological behavior and mechanical properties. Variation in rheological behavior and mechanical properties was studied in terms of the filler composition using natural rubber compounds filled with both carbon black and silica CB/Si = 0/60, 20/40, 30/30, 40/20 and 60/0 phr (parts per hundred rubber is parts of any non-rubbery material per hundred parts of raw gum elastomer (rubbery material)). The rheological behaviour can be showed in measurement of Mooney viscosity and cure time. The Mooney viscosity of rubber compounds increase with the increasing the carbon black in the compounds. The compound filled with CB/Si of 30/30 and 60/0 showed abnormal rheological behaviour in which the cure time decreased suddenly and the increased at certain ratio during the measurement. The mechanical properties such as hardness, abrasion resistance and tensile stress at 300% elongation were studied. In the hardness and abrasion resistance measurement, the higher ratio CB/Si decrease contribution of silica, which resulting smaller of hardness value. Ratio CB/Si 40/20 gives an optimum filler blended. It is also clearly understood that higher abrasion resistance mainly due to the lower hardness value under the same condition. The tensile stress at 300% elongation of rubber compound increased with the increasing carbon black filler.     

微量稀土对工业纯铝中杂质相的变质行为

采用SE,EDAX,TEM他稀土对工业纯铝中富Fe(Si)杂质相的变质作用及机制,结果表明：富铈混合稀土（RE）是一种有效变质剂,可使铝中杂质相由粗大长针（条）状或骨骼变细小的团球状或短棒状,且分布均均匀,提高了材料的力学性能（尤其是塑性）,其变质机制主要是因稀土在固／液界面前前沿的富集,导致了稀土进入杂质相形成（AlFeSiRE)的复杂化合物,或吸附在杂质相表面阻碍其长大,但过量稀土易导致第二相数量增多,降低材料塑性,其加入量应小于 0．07％（质量分数）。     

RE-Al对含钨高铬铸铁变质效果的试验研究

考察了RE，Al对含钨高铬铸铁组织、冲击韧度、硬度、耐磨性等性能的影响。结果表明：铸态未变质的铸铁组织中，奥氏体含量多，碳化物呈粗大板条状分布，晶粒比较粗大；变质后残余奥氏体量明显减少，初生奥氏体显著细化，碳化物由粗大板条状向细板条状、菊花状转变；RE，Al复合变质处理可使铬钨合金白口铸铁的硬度、冲击韧度、耐磨性都得到提高。     

Ecofriendly new nanocomposites coating formulation of zinc reinforced with calcium oxide nanoparticles synthesis from oyster shell

The zinc coating of mild undergoes rapid corrosion for a short period of time in harsh environments. This affects the durable life and overall performance of the zinc coatings. The electrochemical, oxidation, and wear performance, as well as the surface morphological properties of new nanocomposites coating formulations of zinc reinforced with calcium oxide nanoparticles, were studied in order to improve the corrosion and wear performance of zinc coatings. A current density of 1.5–2.0 A/cm² was used for the electrodeposition. The wear, oxidation, hardness, corrosion rate, and morphological properties were evaluated. The characterization of these composite coatings showed low wear rates and higher corrosion and oxidation resistance. At 1.5A/cm² current density, a 65.53% enhancement in the hardness values and 57.14% oxidation protection were obtained. The smaller crystallite size of the deposited sample is the main reason for the lower corrosion and wear resistance and higher hardness values obtained. It was established that waste oyster can be used for the electrodeposition of mild steel to enhance corrosion resistance and hardness values. CaOnp made from oyster shells has been shown to make mild steel more resistant to corrosion, wear, and oxidation.     

化学沉积Ni-P-Al2O3和Ni-P-SiC复合材料的微观组织与物理性能

采用化学沉积方法,可以制备以镍磷合金为基质的复合硬质相粒子的复合材料［１］．镍磷合金颇受青睐之处在于可以调整成分和时效处理温度来改变其组织结构,进而获得广泛变化的性能［２,３］．本文报道化学沉积获得的ＮｉＰ氧化铝和ＮｉＰ碳化硅复合材料的微观组织与...     

Filling and wear behaviors of micro-molded parts made with nanomaterials

Microinjection molding technology and its various modifications represent established processes for micro-molded parts with high accuracy under large scale production. Recently, the use of plastic material with added reinforced fillers has become a potential alternative approach due to its high strength and the ease of batch fabrication. This paper investigates the moldability and wear properties of a polymer with added nanoceramic materials during microinjection molding. In this study, parts with micro-features were successfully manufactured using a custom-made injection machine. The results show that the polymer with added nanomaterials effectively increased the hardness achieved. In addition, a nanoceramic material, such as ZnO, improved wear resistance by 70% when nanoparticles were uniformly dispersed in the polymer and a suitable surfactant solvent was chosen. However, wear resistance decreased significantly if the nanoparticles were not processed well and a proper surfactant solvent was not chosen. The results also show that high hardness did not result in reinforced parts with high wear resistance.     

Modification effects of short carbon fibers on mechanical properties and fretting wear behavior of UHMWPE composites

The present work comparatively studied the modification effects of short carbon fiber (CF) on the mechanical properties and fretting wear behavior of ultra‐high molecular weight polyethylene (UHMWPE)/CF composites. The interactions between CFs and UHMWPE interface were also investigated in detail. The results showed that, with the increase in fiber content, the compressive modulus and hardness of the composites increased, while its impact strength decreased. It was found that filling of CF can reduce the friction and wear of UHMWPE. In addition, the UHMWPE‐based composites reinforced with nitric acid‐treated CF exhibited better mechanical properties, lower friction coefficient, and higher wear resistance than those of untreated UHMWPE/CF composites. This was attributed to the improvement of interfacial adhesion and compatibility between CF and UHMWPE matrix caused by surface chemical modification of CF. Copyright © 2015 John Wiley & Sons, Ltd.     

Comparative study of the effects of nano‐sized and micro‐sized CF and PTFE on the thermal and tribological properties of PEEK composites

The tribological characteristics of PEEK composites fretting against GCr 15 steel were investigated by a SRV‐IV oscillating reciprocating ball‐on‐disk tribometer. In order to clarify the effect of type and size of fillers on the properties of PEEK composites, nano‐sized and micro‐sized CF and PTFE fillers were added to the PEEK matrix. The thermal conductivity, hardness, and fretting wear properties of PEEK composites reinforced by CF or PTFE were comparatively studied. The results showed that the type and size of the fillers have an important effect on both the friction coefficient and wear rate, by affecting their thermal conductivity, hardness, as well as the surface areas of their transfer films. In comparison, the effect on improving the tribological properties of micro‐sized CF was superior to that of nano‐sized CF, while the effect of nano‐sized PTFE was superior to that of micro‐sized PTFE. Considering the acceptable friction coefficient and wear rate of the composite under the fretting wear test, it seemed that 4% nCF, 20% mCF, 2% nPTFE and 10% mPTFE were desired additive proportions. And it also can be found that during the fretting wear test, the abrasive and adhesive wear resulted in accumulative debris at the contacting surface. The transfer films made of debris were formed on the counterfaces.     

Boron carbide-copper infiltrated cermets

Porous boron carbide preforms, prepared with and without excess carbon, were infiltrated with a Cu-Si alloy. Contrary to unalloyed copper, the Cu-Si alloy wets and infiltrates the porous preforms. A thermodynamic analysis of the B-C-Cu-Si system indicated that a Si content of the alloy above 15 at% leads to the formation of SiC. At higher Si content, the composition of boron carbide in contact with the melt also changes towards higher boron content. Metallographic examination validated these conclusions. The SiC compound forms preferentially around the free carbon particles in preforms containing excess carbon, and also in the vicinity of carbide that did not contain any excess carbon. Eventually, SiC, a product of the reaction between the carbide and the melt, forms a continuous barrier that impedes completion of the reaction and accounts for the limited increase of hardness as a result of lengthy heat treatments.