Cu、Zn对Mg晶粒尺寸以及微观组织影响

通过向镁熔体中单独和复合添加一定量的Cu及Zn元素,探究了Cu、Zn对镁晶粒尺寸和微观组织的影响并阐释了其细化机理;同时深入表征了Cu、Zn单独及复合添加后合金的物相组成。结果表明：向纯Mg中加入Cu、Zn和Cu、Zn复合添加后,晶粒依次由柱状晶转变为等轴晶。单独加Cu、单独加Zn和Cu、Zn复合添加后,平均晶粒尺寸由纯Mg的1270μm分别减小至470、120和85μm。单独加Zn对Mg的晶粒细化机理主要为Zn元素的溶质效应;单独加Cu对Mg的晶粒细化机理主要为Cu元素的溶质效应和CuMg2相对晶界的钉扎作用;Cu、Zn复合添加后细化效果更好主要是因为Cu、Zn元素的复合溶质效应及第二相对晶界的钉扎作用更为强烈。此外,单独加Zn后,第二相呈颗粒状分布于基体中,合金中的物相组成为α-Mg+MgZn;单独加Cu后,第二相形貌呈网状,合金中的物相组成为α-Mg+CuMg2;Cu、Zn复合添加后,Mg-5Cu-3Zn晶界上的第二相呈现出两种不同的形貌,经鉴定,连续的块状第二相为CuMg2相,不连续的鱼骨状第二相为CuMgZn相。     

Effect of heat treatment on mechanical and wear properties of Zn–40Al–2Cu–2Si alloy

In order to determine the effect of heat treatment on the mechanical and wear properties of Zn–40Al– 2Cu–2Si alloy, different heat treatments including homogenization followed by air-cooling (H1), homogenization followed by furnace-cooling (H2), stabilization (T5) and quench–aging (T6 and T7) were applied. The effects of these heat treatments on the mechanical and tribological properties of the alloy were studied by metallography and, mechanical and wear tests in comparison with SAE 65 bronze. The wear tests were performed using a block on cylinder type test apparatus. The hardness, tensile strength and compressive strength of the alloy increase by the application of H1 and T6 heat treatments, and all the heat treatments except T6, increase its elongation to fracture. H1, T5 and T6 heat treatments cause a reduction in friction coefficient and wear volume of the alloy. However, this alloy exhibits the lowest friction coefficient and wear volume after T6 heat treatment. Therefore, T6 heat treatment appears to be the best process for the lubricated tribological applications of this alloy at a pressure of 14 MPa. However, Zn–40Al–2Cu–2Si alloy in the as-cast and heat-treated conditions shows lower wear loss or higher wear resistance than the bronze.     

Correlations among stress corrosion cracking,grain-boundary microchemistry,and Zn content in high Zn-containing Al–Zn–Mg–Cu alloys

The correlations among the corrosion behaviour, grain-boundary microchemistry, and Zn content in Al–Zn–Mg–Cu alloys were studied using stress corrosion cracking (SCC) and intergranular corrosion (IGC) tests, combined with scanning electron microscopy (SEM) and high-angle angular dark field scanning transmission electron microscopy (HAADF-STEM) microstructural examinations. The results showed that the tensile strength enhancement of high Zn-containing Al–Zn–Mg–Cu alloys was mainly attributed to the high density nano-scale matrix precipitates. The SCC plateau velocity for the alloy with 11.0 wt.% Zn was about an order of magnitude greater than that of the alloy with 7.9 wt.% Zn, which was mainly associated with Zn enrichment in grain boundary precipitates and wide precipitates-free zones. The SCC mechanisms of different Zn-containing alloys were discussed based on fracture features, grain-boundary microchemistry, and electrochemical properties.     

Zn_(0.7)Co_(0.3)(Ti_(1-x)Sn_x)Nb_2O_8陶瓷微波介电性能研究

采用传统固相法制备Zn0.7Co0.3(Ti1-xSnx)Nb2O8(x=0.1,0.15,0.2,0.25,0.3,0.35)微波陶瓷。研究了Sn取代Ti对Zn0.7Co0.3(Ti1-xSnx)Nb2O8微波介质陶瓷的物相结构与介电性能的影响。XRD研究表明,Zn0.7Co0.3(Ti1-xSnx)Nb2O8陶瓷主晶相为ZnTiNb2O8,有极少杂相Zn0.17Ti0.5Nb0.33O2存在;随着Sn含量的增加,陶瓷晶格常数增大,晶胞体积变大,陶瓷密度增大;电子扫描显微镜(SEM)显示随着Sn含量增加陶瓷结构致密;相对介电常数εr逐渐变小,温度系数τf逐渐变小,Q×f值逐渐增大;当Sn含量为0.35时,烧结温度为1 080℃,εr=30.5,Q×f=46 973GHz,τf=-45.4×10-6/℃。     

黑龙江黑土区设施土壤锌积累特征及风化煤制剂修复研究

对黑龙江省黑土区设施土壤中锌(Zn)积累特征进行分析,并进行风化煤制剂修复研究。结果表明:五常、肇东两地部分设施土壤Zn含量超标,五常市属于中等强度变异,肇东市属于弱变异;Zn形态以残渣态为主,弱酸可提取态含量较少,移动性较弱;施用风化煤制剂能显著降低黑土区设施土壤中弱酸可提取态Zn含量(P0.05),以处理7(风化煤1500 kg/hm~2,复合肥375 kg/hm~2)修复效果最优;相关性分析结果表明,该制剂中风化煤起主导作用。     

Precipitation kinetics of GP zones,metastable η′ phase and equilibrium η phase in Al−5.46wt.%Zn−1.67wt.%Mg alloy

Thermal analysis is one of the most used techniques for analyzing the behavior of aluminum alloys in order to analyze the precipitation of Guinier?Preston (GP) zones and different phases formed. In the present work, the behavior of the Al?5.46wt.%Zn? 1.67wt.%Mg alloy was studied. The mechanism and kinetics of precipitation of the GP, the metastable phase η′ and the equilibrium phase η were investigated using DSC carried out between room temperature and 480 °C at heating rates of 5, 10, 15 and 20 °C/min. The apparent activation energies, calculated by DSC from isothermal calculation method using JMAK model, for GP, η′ and η were 56, 79 and 96 kJ/mol, respectively, and those calculated by non-isothermal calculation method using Kissinger methods were 57, 82 and 99 kJ/mol, respectively. The values of Avrami parameter, n, from isothermal calculation, during the precipitation of the GP, η′ and η were 1.103, 1.9075 and 1.92, respectively, and those calculated by non-isothermal were 0.86, 2.30 and 2.24, respectively. The results show that GP zones formation is governed by the migration of Zn and Mg atoms while the precipitation of the η′ metastable phase and the η stable phase is governed by both the migration and the diffusion of the solute atoms.     

利用含锌硫酸废水制备聚硅酸铁锌及处理含肼废水

以含锌硫酸废水、铁屑、硅酸钠为原料制备聚硅酸铁锌絮凝剂。对制备条件的优化结果表明,当SiO2质量分数为0.020~0.025,n(Fe+Zn)/n(Si)为1.5~2.0,硅酸活化的pH为1.56~2.12,活化时间为12~16 h时,制备的聚硅酸铁锌絮凝剂的絮凝性能优良。用制备的聚硅酸铁锌絮凝剂二段处理含肼废水,结果表明,经该絮凝剂处理后,废水COD从7 065 mg/L降低到1 235 mg/L,COD去除率达到了82.5%,pH从13~14降低到9~10,降低了含肼废水后续生物处理的负荷和冲击。     

Impact of oxygen concentration during the deposition of window layers on lowering the metastability effects in Cu(In,Ga)Se2/CBD Zn(S,O) based solar cell

The purpose of the present paper is to focus on the impact of oxygen gas partial pressure during the sputtering of i‐ZnO and ZnMgO on the transient behavior of Cu(In,Ga)Se₂ (CIGSe) based solar cells parameters when a CBD‐Zn(S,O) buffer layer is used. Based on electrical characterization of cells, it is observed that the effect of light soaking is different on J–V characteristics depending on whether oxygen is or is not present during the first deposition time of the i‐ZnO or ZnMgO layers. In fact, when cells are prepared with standard i‐ZnO, the efficiencies are very low and a pronounced transient behavior is observed. However, when the first 10 nm of i‐ZnO or ZnMgO is formed by sputtered layer without adding oxygen during the process, depending on the thickness of the buffer layer, the transient effects strongly decreases. It is then possible to get stable cells reaching efficiencies quite similar to the CdS reference cells, especially with ZnMgO, without any post‐treatments. Copyright © 2015 John Wiley & Sons, Ltd.     

锌锰电池用节锌喷塑锌筒

在锌锰电池中,锌筒起到负极材料、集流体和容器3个作用。在锌筒外壁上,用静电喷涂一层塑料,替代部分起容器作用的锌,不影响锌锰电池的连放、间放、防漏和高温贮存等各项性能。这项技术能降低锌锰电池的锌耗和成本,适用于高放电容量和大尺寸的电池。