脉冲加热惰性气体熔融红外吸收-热导法测定镍基高温合金中痕量氧、氮

采用电极脉冲炉惰性气体熔融试样,红外吸收法测定镍基高温合金中痕量氧,热导检测法测定痕量氮。针对镍基高温合金中痕量氧、氮的测定,通过采用功率控制方式及分析时间的合理选择,实现了该方法测定镍基高温合金中痕量氧、氮,氧的RSD小于5%(n=8),氮的RSD小于2%(n=8),测定结果与认可值吻合较好,在镍基高温合金样品的测定中具有简便、快速、稳定、准确等优点。     

产品结构对轨道车辆橡胶弹性元件防火性能的影响

研究产品结构对轨道车辆橡胶弹性元件防火性能的影响。通过模拟橡胶弹性元件结构,对不同类型的橡胶-金属结构试样的防火性能试验得出:当橡胶面积占比相同时,橡胶中有金属隔板的试样的防火性能明显改善,金属隔板越多,防火性能越好;随着橡胶面积占比的减小,不同结构试样的最大烟密度和最大平均热释放速率均减小,防火性能均提高;橡胶中无金属隔离的试样在橡胶面积占比小于60%时,其防火性能可达到EN 45545-2的HL2等级要求,橡胶中有两块金属隔板或橡胶中心有金属柱体的试样在橡胶面积占比达到80%时,其防火性能仍可达到EN 45545-2的HL2等级要求。     

聚合物DSC测试结果的影响因素探讨

以聚酯切片为例,对差示扫描量热法(DSC)测定聚合物的热性能的影响因素进行探讨。结果表明,盛放试样的容器可用国产铝坩埚;进行二次升温时升温速率宜低;根据试样的特性,用氮气保护,氮气流量以20mL/min为宜;试样量为5～10mg,粒径小于0.5 mm,可以降低测试成本和提高结果的准确度。     

从含巯基乙酸的焦磷酸盐槽液中沉积铜镍合金

前言 Cu-Ni合金是均匀的固溶体,具有较高的耐蚀性,良好的韧性和较好的延展性,用途较广泛;具有不同比例元素的Cu-Ni合金,可广泛地用于各种各样的目的,如船舶装置、热交换管、化学容器,贵金属的电镀底层,以及本尼迪特金属”都是这些合金典型的使用。特别是Cu75％—Ni25％合金,众所周知,是用来制造金属硬币的合金。     

胶粘剂固含量测定影响因素分析

分析了X98-11酚醛缩醛胶粘剂固含量测定中干燥时间、干燥温度、试样取样量、试样在容器底部的均匀程度、试样混合均匀程度、电热鼓风干燥箱的炉温均匀性等对试验结果影响。试验结果表明,只有正确按试验方法进行试验,准确分析各种影响因素,才能保证试验结果的准确性。     

硫酸铵-氨水溶样测定氧化锌含量

研究采用硫酸铵-氨水溶解氧化锌试样,EDTA滴定法测定氧化锌含量.结果表明,用200 g·L<'-1>硫酸铵溶液10 mL,5 mL氨水溶解分析试样,搅拌5 min后试样中氧化锌溶解完全,金属锌、氧化铁等杂质不溶,氧化锌的测定不受这些杂质的干扰,测定结果与传统溶样方法的测定结果相吻合,相对标准偏差小于0.1%.     

Al+Mg-Al、Al+Si复合添加剂对低碳镁碳砖抗氧化性的影响

以电熔镁砂、天然鳞片石墨、炭黑和沥青为主要原料,分别以总质量分数为4%的金属Al和Mg-Al合金、金属Al和Si为抗氧化剂,以酚醛树脂为结合剂,制备了两组w(C)≈6%的镁碳砖试样,并研究了试样在氧化气氛下分别经600、1000和1400℃保温2h后的抗氧化性。结果表明:只添加金属Al粉时,试样在1400℃下有较好的抗氧化性能;只添加Mg-Al合金时,试样在600℃下具有较好的抗氧化性能;金属Al粉与Mg-Al合金按2:2质量比添加或金属Al粉与Si粉按3:1质量比复合添加时,试样在600～1400℃范围内的抗氧化效果均较好。     

试验介质承接装置的设计

通过对试验介质承接装置,包括对容器、密封盖、插口、环形试样架及支脚等的设计,解决了试验介质的承接、试样悬挂及浸泡。该装置含有容器和密封盖,可减少试验介质的挥发,容器内部设置有可拆卸的环形试样架和插口,将试样均匀悬挂于试样架上,将支脚一端的插杆固定于插口内,通过调整伸缩杆的长度,可将试样浸泡于试验介质中;介质液面调整灵活,试样安装便捷,浸泡规范,提高了试验结果的准确性,试验后介质清理更换方便,减少了劳动强度。     

废水中甲胺的气相色谱分离测定

工业废水中的痕量二甲胺在三乙醇胺色谱柱上得到分离并测定，水样经碱化处理使二甲胺释放至密闭容器顶空气体中，抽取该顶空气体进行色谱分析，试样重复测定相对标准偏差在５％以内，试样回收率在９６％－１０２％间，可准确定量测定。     

用于金属容器的水性涂料组合物

公开号　ＣＮ1255935Ａ　　申请人　瓦尔斯巴有限公司　　地址　美国明尼苏达州　　公开一种用于金属容器的水性涂料组合物,一种涂覆金属容器的方法,以及用作食品或饮料容器的金属制品。水性涂料组合物是热塑性、可自行交联的材料,它包含:(ａ)环氧树脂;(ｂ)水分散性丙烯酸类树脂;(ｃ)可任选的固体填料;(ｄ)短效碱;以及含水载体,该水性涂料组合物中每千克不挥发性材料含有450克或更少的挥发性有机化合物。用于金属容器的水性涂料组合物     

The effect of copper alloy mold tooling on the performance of the injection molding process

The performance of copper alloy mold tool materials in injection molding has been examined with respect to cycle time, part quality and energy consumption using in‐process monitoring techniques. A mold insert manufactured from conventional tool steel was compared to four identical inserts made from beryllium‐free copper alloys with copper contents ranging from 85 to 96%. Injection molding trials using high density polyethylene and polybutyl terepthalate were performed using a highly instrumented injection molding machine. Results showed that copper alloy mold tools exhibited cooling rates up to 29% faster than conventional tool steel and that cooling rate was related to thermal conductivity of the alloy. Lower cycle times were achievable with copper alloy than for tool steel before part quality deterioration occurred. The results suggest that copper alloy tooling has the potential to achieve significant reductions in cycle time without detriment to the process or product quality. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers     

Mercury porosimetry studies I. Low melting alloy intrusion studies as an aid to the interpretation of mercury porosimetry data

Low melting alloy intrusion experiments offer a convenient and simple technique to aid in interpretation of mercury intrusion curves. By substituting a low melting alloy (Cerrolow^® 117, m.p. 47 °C) for mercury in an intrusion experiment, it is possible to ‘freeze’ the intrusion process at any given pressure merely by cooling the alloy below its melting point. The ‘frozen’ intrusion sample may then be sectioned and examined under the microscope to determine how the metal is entering the porous structure.Two samples of poly(vinyl chloride) resin were investigated by this technique. The inter-particle penetration process was found to be consistent with the notion of bed depacking rather than bed penetration. The intraparticle penetration process was observed to be different for the two samples investigated. In one case the limiting pores were located in the outer surface while in the other sample they were located in the interior of the particle.     

Effect of simulated combustion atmospheres on oxidation and microstructure evolution of aluminum alloy 5052

Among the common materials, metals can be hardly destroyed by flame or the heat emanating from a normal fire. Consequently, investigation on the thermal patterns produced on metallic objects after fire exposure can provide important physical evidence for fire cause/origin determination. Aluminum alloy is widely used in our daily life and the industry; hence, it can be easily found on a domestic or industrial fire scene. In this paper, the aluminum alloy 5052 was exposed in the simulated combustion gases with and without kerosene in the range of 300 to 500°C. Mass change, morphologies, and microstructures of each sample were carefully characterized by thermogravimetric analysis, morphologic observation, and electron microscopy observation with energy‐dispersive spectroscopy analysis after exposure. As expected, the microstructure of alloy changed during high temperature exposure. At the same time, an oxide scale formed and was thickened on the surface of alloy. The results reveal that the temperature can significantly affect the growth of oxide scale and the metallurgical microstructure of alloy. It is noteworthy that the presence of kerosene in the combustion gas accelerated oxidation rate and produced oxide scales different from those formed in air. These feature evolutions in surface oxide are expected to offer complementary insight on determining the fire characteristics, such as the exposure temperature, period and whether liquid accelerant is involved.     

Exceptional improvement in the wear resistance of biomedical β-type titanium alloy with the use of a biocompatible multilayer Si/DLC nanocomposite coating

A silicon/diamond-like carbon (Si/DLC) multilayer nanocomposite coating (MNC) was applied to the Ti–29Nb–13Ta?4.6Zr (TNTZ) alloy to improve its wear resistance and durability. The Si/DLC MNC on the TNTZ alloy demonstrated an extremely low wear rate of 6.2 × 10^?10 mm³N^?1mm^?1. Moreover, the wear track depth after one million wear cycles was found to be only 220 nm, while the thickness of the entire coating was 370 nm. Furthermore, cell culture tests demonstrated that the Si/DLC MNC samples exhibited better biocompatibility than the TNTZ alloy samples. A quantitative comparison of the cell adhesion behavior of the TNTZ and Si/DLC MNC samples indicated that 60% of the surface of the Si/DLC MNC sample was covered with cells, which was approximately twice the surface of the TNTZ alloy sample covered with cells. In addition, no dead cells were observed on the Si/DLC MNC samples, indicating that the Si/DLC MNC samples exhibited no toxic effects against the MC3T3 cells. These results indicate that the Si/DLC MNC enhances the wear resistance of the TNTZ alloy and improves its biofunctionality, thus making it a potential candidate for use in long-term implant applications.     

Diminishing Marginal Utility of Cooling Rate Increase on the Crystallization Behavior and Physical Properties of a Lipid Sample

It is well established that variation of the rate of cooling (r) of a lipid sample is an effective tool to influence the crystallization process and effect changes in network structure and physical functionality. However, the extent of the physical changes does not always justify the extent to which the cooling rate must be altered. It is therefore important to understand the rates at which marginal changes in physical functionality begin to diminish, and to understand the mechanisms which introduce such limitations. A commercially available cocoa butter alternative, Temcote (Bunge Oils, Bradley, IL), was crystallized under cooling rates varying from 0.1 to 20 °C min⁻¹. The growth mode and polymorphism of each sample was studied using DSC and X-ray diffraction (XRD). The hardness of the sample was monitored using cone penetrometry and its solid fat content (SFC) evolution was monitored using a temperature controlled pulse-NMR. The data demonstrates that the melting profile of the sample could be greatly manipulated over a relatively narrow range of cooling rates. Large increases in cooling rate increase the final SFC of the sample by approximately 6%. Doubling the cooling rate increases the hardness of the sample 50%. Variation of the cooling rate as a tool to modify physical functionality of the network was found to be effective only for cooling rates lower than 5 °C min⁻¹.     

铅火试金富集—发射光谱法测定化探样品痕量金、铂和钯

试样用铅火试金富集铂组元素及金,加入1 mg银,在950℃熔融得到含贵金属的铅扣。铅扣与熔渣分离后在900℃灰吹得含铂、钯和金的银合金粒。把合金粒装入电极,以发射光谱法同时测定铂、钯和金的含量。     

水溶液中电沉积Ni-La-P合金的研究

含稀土金属的合金具有特殊的功能,常用作电催化材料。由于稀土元素的标准平衡电位较负,在水溶液中很难沉积。因此,采用柠檬酸和氯化铵为混合配位体,硼酸为稳定剂从水溶液中电沉积出Ｎｉ－ Ｌａ－ Ｐ合金镀层。详细介绍了镀液各个组分及工艺条件的选择,获得灰白色、细致的合金镀层。对所得的镀层进行ＳＥＭ 观察和ＸＰＳ分析,结果表明所得镀层为Ｎｉ－ Ｌａ－ Ｐ合金。     

Joining of aluminum and ceramic substrates by interposing molten aluminum–silicon alloy

The effects of interposing a molten aluminum alloy layer between pure aluminum and silicon nitride on the strength of joining and properties of the joined sample were investigated. An aluminum-based alloy containing 12 wt% silicon with a melting point lower than the 660°C melting point of pure aluminum was joined to pure aluminum and a silicon nitride substrate by using polymethylphenylsiloxane. A specimen with the same joining area (1600 mm²) and no alloy layer was prepared for comparison. In thermal cycling tests of Δ190 K, cooled at –40°C and heated at 150°C, the specimen without the alloy layer failed after 200 cycles, whereas the specimen with the alloy layer failed after 500 cycles. The bending strength of the sample with the alloy was approximately 1.5 times that of the sample without the alloy. These results indicate that the alloy layer facilitated the strong joining of the aluminum and substrate.     

Influence of surface pretreatment and electrocoating parameters on the adhesion of cathodic electrocoat to the Al alloy surfaces

Adhesion of cathodic electrocoat films to the aluminum alloys 2024-T3 bare and Alclad 2024-T3 with different pretreatments and with different cathodic electrocoat process parameters was investigated. The pretreatments studied were acetone wipe and alkaline cleaning. The cathodic electrocoat process parameters studied include variation of cathodic electrocoating voltage and time. Adhesion performance was evaluated by measuring the delamination time and percent delamination of the electrocoat from the alloy surface by placing the small specimen of the sample in the N-methyl pyrrolidinone (NMP) solution at 60°C until the film lifts off or for 2 h whichever comes first. NMP times for electrodeposited film delamination from alkaline cleaned surfaces were found to be higher than the acetone wiped and or those of as-supplied metal surfaces. There was not much effect of acetone cleaning of these alloy surfaces on the adhesion performance of the cathodic electrocoat. The voltage–current (of cathodic electrocoating process) relationships for alkaline cleaned surfaces were also found to be significantly different from the other two types of surfaces. The NMP times of cathodic electrocoat delamination at lower cathodic electrocoating voltage and lower electrocoating times were higher than those at higher cathodic electrocoating voltage and electrocoating times for alkaline cleaned 2024 bare surfaces. Electrocoat thickness developed on the surfaces during the electrodeposition process increased with increasing electrodeposition voltage and time as anticipated.     

冷却方式对尖晶石型红外辐射陶瓷结晶的影响

在红外陶瓷制备过程中,不同的冷却方式对红外陶瓷的结晶有一定的影响,进而影响到陶瓷的红外辐射率。采用XRD法研究了Fe、Mn、Co、Cu、Ni尖晶石型红外辐射陶瓷在制备过程中的冷却方式对尖晶石结晶的影响。含锰的尖晶石根据含锰量的高低可采用水中淬冷或在空气中急冷的方式,不能采用自然冷却的方式;高锰含量的配方必须采用水中淬冷的冷却方式;锰含量较低时,可采用空气中急冷的方式。为保证尖晶石晶体的结晶良好,镍尖晶石用在空气中冷却的方式最好。本实验采用的3种冷却方式对钴尖晶石都不太适用,使降温速率比自然冷却稍快些,但比空气中急冷稍慢些,可望有更好的效果。铜尖晶石可采用空气中急冷的方式,既能保证尖晶石的充分结晶,又能使反型铜尖晶石结构变为混合型结构,有利于红外辐射率的提高。