材料期刊网

BEHAVIOR OF FLOW STRESS OF ALUMINUM SHEETS USED FOR PRESSURE CAN DURING COMPRESSION AT ELEVATED TEMPERATURE

G.S. Fu , W.Z. Chen , K.W. Qian

金属学报(英文版)

The behavior of flow stress of Al sheets used for pressure can prepared by different melt-treatment during plastic deformation at elevated temperature was studied by isothermal compression test using Gleeble1500 dynamic hot-simulation testing machine. The results show that the Al sheets possess the remarkable characteristic of steady state flow stress when they are deformed in the temperature range of 350-500℃ at strain rates within the range of 0.01-10.0s-1. A hyperbolic sine relationship is found to correlate well the flow stress with the strain rate, and an Arrhenius relationship with the temperature, which implies that the process of plastic deformation at elevated temperature for this material is thermally activated. Compared with the Al pieces prepared by no or conventional melt-treatment, hot deformation activation energy of Al sheets prepared by high-efficient melt-treatment is the smallest (Q = 168.0kJ/mol), which reveals that the hot working formability of this material is very better, and has directly to do with the effective improvement of its metallurgical quality.

关键词: Al sheets used for can , null , null

K-RE变质处理改善Fe-V-W-Mo合金性能的研究

符寒光 , 李定 , 邢建东

稀有金属材料与工程

研究了K-RE变质处理对Fe-V-W-Mo合金机械性能和热物理性能的影响.结果发现,Fe-V-W-Mo合金经K-RE变质处理后,硬度和红硬性略有增加,冲击韧性提高41.82%,达到11.09J/cm2,耐磨性和导热系数提高,热膨胀系数减小.分析了K-RE改善Fe-V-W-Mo合金性能的机理,并制造了K-RE变质Fe-V-W-Mo合金轧辊,在热轧生产中使用获得了良好的效果.

关键词: K-RE变质处理 , Fe-V-W-Mo合金 , 机械性能 , 物理性能 , 轧辊

6W@60K脉管制冷机的优化及实验研究

张安阔 , 吴亦农 , 刘少帅 , 蒋燕阳 , 蒋珍华 , 陆志

工程热物理学报

设计制作了一台6W@60K同轴型脉管制冷机,用于冷却一碲镉汞红外探测器.通过脉管制冷机结构特点的分析及系统阻抗特性的研究,给出压缩机内部气体阻抗实虚部与PV功转换效率之间的变化规律,从而为设计出高效的脉管制冷机提供有益指导.完成了该脉管制冷机的设计、制作及性能测试工作.实验表明该制冷机在150 W电功输入下可获得低于40 K最低温度,195 W电功输入下60 K可获得6W制冷量,比卡诺效率为12％.

关键词: 脉管制冷机 , 6W@60K , 阻抗

35K／0．6W多路旁通单级脉冲管制冷机

杨俊玲 , 蔡惠坤 , 杨鲁伟 , 周远

工程热物理学报

针对35K温区应用这一制冷要求，围绕多路旁通方案高频同轴脉冲管制冷机这一拥有我国自主知识产权的技术开展了系统的实验研究。实验表明多路旁通流通面积和惯性管长度都有最佳值，是关键影响因素；引入双向进气后，制冷剂温度降低10K左右，是35K应用不可缺少的因素。实验表明多路旁通优于传统单级和二级的形式。在原理样机阶段，实现了200W输入功率下最低温度2叠1K，0．6W／35K的性能。在此基础上，完成了另一套全焊接结构的实用样机的研制，测试得到了200W输入功率下O5W／34K的性能。这一工作的顺利开展代表了高频多路旁通方案实用化的突破，为我国35K高频微型低温制冷机的研制奠定了基础。

关键词: 多路旁通 , 高频脉冲管制冷机 , 同轴 , 35 , K温区

Densification of the Tungsten Heavy Alloys at 1473 K and Fabrication of W-Mo System FGM with Density Gradient

Huaping XIONG , Lianmeng ZHANG , Junguo LI , Runzhang YUAN

材料科学技术（英文）

The tungsten heavy alloys with Ni-Al and Fe-Al additives were sintered by hot-press method at 1473 K for 1 h. It was found that the relative density of the W-Fe alloy could be increased evidently by addition of Al. However, the relative density of W-Ni-Al alloy with low content of Al was conversely decreased considerably compared with that of W-Ni alloy. The causes have been studied. The sintering experiments of Mo alloy and W-Mo alloys with 3 wt pct Fe-1.5 wt pct Al additives were also carried out under the same sintering condition of low temperature. Finally, W-Mo system FGM with density gradient was successfully fabricated. Its density changed gradually from 17.0´103 kg/m3 to 9.5´103 kg/m3 within the middle 1.1 mm thickness range.

关键词:

0.2 W@20.6 K单级高频脉冲管制冷机研究

陈六彪 , 金海 , 朱文秀 , 王俊杰 , 周远 , 顾开选 , 季伟

工程热物理学报

本文介绍一台单级高频脉冲管制冷机的实验结果,研究了充气压力、运行频率、热端温度及冷头朝向等参数对制冷机性能的影响.该制冷机采用多路旁通方案、同轴结构,联合采用双向进气和惯性管气库进行调相.长颈管穿过压缩机内部后密封在气库里,气库、压缩机与脉冲管耦合成一体,结构紧凑.在充气压力1.7 MPa,输入电功260 W时,能够在20.6 K获得0.2 W,在24.1 K获得0.5 W的制冷量;在268 W输入电功,38 Hz运行频率条件下,无负荷最低温度18.6K是单级高频脉冲管制冷机在国际上首次获得的最低温度.

关键词: 单级 , 多路旁通 , 高频 , 20 K

Subsolidus phase relations in the systems K2O-ZnO-AO(3) (A = Mo, W)

Journal of Alloys and Compounds

The subsolidus phase relations of the systems K2O-ZnO-AO(3) (A= Mo, W) have been investigated by X-ray diffraction (XRD) analyses. The phase diagrams have been constructed. There are six binary compounds and two ternary compounds in the K2O-ZnO-MoO3 system, it can be divided into 11 three-phase regions. The K2O-ZnO-WO3 system consists of six binary compounds and one ternary compound. This system can be divided into 9 three-phase regions. DTA results indicated the compounds K2MOO4 and K2WO4 are not suitable to be fluxes for ZnO crystal growth. (c) 2006 Elsevier B.V. All rights reserved.

关键词: ZnO;x-ray diffraction;phase diagram;DTA;crystal growth;zno single-crystals;hydrothermal growth;zinc oxide;potassium;polymolybdates;polytungstates;diffraction;vapor

K-RE变质处理改善Fe-V-W-Mo合金组织

符寒光 , 邢建东 , 李言祥

稀有金属材料与工程

用K-RE对Fe-5%V-5%W-5%Mo-5%Cr-3%Nb-2%Co-2%C合金变质处理,使凝固组织发生了明显的变化,不仅碳化物和基体组织明显细化,还出现共晶碳化物断网现象,产生了较多的小块状和颗粒状碳化物.经K-RE变质处理Fe-V-W-Mo合金加热温度950℃时,碳化物断网明显,加热温度1 000℃时,多数碳化物已断网,并出现了数量较多的颗粒状碳化物,加热温度1 050℃时,碳化物网状组织全部消失,大部分碳化物变成了球状组织.

关键词: 变质处理 , K-RE , Fe-V-W-Mo合金 , 共晶碳化物 , 团球化

温度对高W含量K416B镍基合金拉伸行为的影响

谢君 , 于金江 , 孙晓峰 , 金涛 , 杨彦红

金属学报 doi:10.11900/0412.1961.2014.00622

在不同温度对高W含量K416B镍基合金进行拉伸性能测试及组织形貌观察,研究了温度对合金拉伸行为的影响规律.结果表明,在20～800℃,合金的屈服强度与抗拉强度随着温度的升高而增加,高于800℃后,合金的拉伸性能逐渐降低.合金室温拉伸变形特征为位错剪切γ'相或以Orowan机制越过γ,相,且切入γ'相位错可分解形成层错.随着温度升高,合金基体内的位错密度逐渐增加,其中,800℃拉伸时,合金基体内形成高密度位错缠结,可起形变强化作用,是合金具有较高拉伸强度的主要原因.随着温度进一步升高,切入γ'相的位错数量增加,致使合金强度逐渐降低.在中低温条件下,裂纹主要沿大尺寸M6C碳化物处萌生与扩展,致使合金发生脆性断裂.而高温拉伸期间,合金主要以微孔聚集方式沿γ+γ'共晶界面发生连接开裂,是合金发生韧性断裂的主要原因.

关键词: K416B镍基合金 , 拉伸行为 , 变形特征 , 断裂机制

钛合金表面K2Ti6O13w涂层的制备及其生物活性

功能材料

K2Ti6O13晶须不仅具有优越的力学性能和良好的生物学特性,而且具有与常规Ti合金相近的膨胀系数.本研究尝试选用K2Ti6O13晶须(K2Ti6O13w)作为生物活性涂层材料,利用BCC方法(混合-包埋-煅烧)在Ti合金基体上成功制备了K2Ti6O13w涂层,并对涂层的表面形态、结合强度和生物活性进行了研究.结果表明,涂层由K2Ti6O13晶须和少量的TiO2和K2Ti4O9组成,其表面粗糙多孔.由于膨胀系数的良好匹配,涂层与基体之间具有较高的结合强度,达24MPa.模拟体液培养后,涂层表面沉积了一层多孔的骨状羟基磷灰石,它由平均直径20nm,长200nm的羟基磷灰石纳米线组成,这表明钛酸钾涂层具有良好的生物活性.涂层较高的生物活性与其独特的生化特性和组分密切相关.

关键词: 钛酸钾晶须 , 钛合金 , 混合-包埋-煅烧 , 模拟体液 , 生物活性