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1.
ICP—AES法测定合金中的杂质元素   总被引:5,自引:0,他引:5  
刘继升 《贵金属》1998,19(3):46-50
研究了Au-Ni(Y,Gd),Au-Cu,Au-Ni-Cu,Au-Cu-Ni-Zn(Mn)合金中的杂质元素(Pb,Sb,Bi,As,Sn,Fe,Al,Zr,Be,V,Ti,In)用Y作载体的共沉淀分离富集方法,富集物转成盐酸液后用ICP-AES法测定,试液中共存元素间的干扰用等效浓度法校正,取试样1.25克时分析范围0.0004%~0.20%,RSD一般不超出±10%。  相似文献   

2.
Cu基形状记忆合金的时效   总被引:5,自引:2,他引:5  
对比研究了时效对亚共析Cu-12.0Al-5.0Ni-2.0Mn-1.0Ti(wt.-%)合金与Cu-20.0Zn-6.0Al-微量B(wt.-%)合金热稳定性的影响。结果表明,无论在母相状态或马氏体相状态,Cu-Al-Ni合金的时效热稳定性均远优于Cu-Zn-Al合金。Cu-Al-Ni合金母相状态时效伴随着DO_3有序畴长大,基体中Al、Ni、Mn等元素贫化,导致M_s点升高,马氏体转变量降低。Cu-Zn-Al合金母相状态时效伴随贝氏体转变,引起基体富Zn富Al,导致M_s点下降,马氏体量降低。Cu-Al-Ni合金高的时效热稳定性可能来源于Ni对Al、Cu等原子扩散的阻碍作用。  相似文献   

3.
稀盐酸浸提海洋锰结核中有价金属   总被引:1,自引:0,他引:1  
对在稀盐酸中以黄铁矿作还原剂的太平洋锰结核浸出过程进行了研究,探讨了黄铁矿与锰结核的质量比(R)、初始盐酸浓度、液固比(L/S)和浸出温度等诸因素对锰结核中有价金属元素Cu、Ni、Co、Mn及Fe浸出的影响。结果表明,当R为03,C初(HCl)15mol/L,L/S10∶1,90℃及浸提90min的情况下,Cu、Ni、Co、Mn、Fe浸出率分别为9577%、9380%、9680%、8909%、4906%;而当C初(HCl)为10mol/L,其它条件相同,金属提取率分别为9184%、8960%、8667%、8083%、063%。锰结核原料中Si、Al等杂质元素浸出后存留在浸出渣中。  相似文献   

4.
高纯钨中杂质元素的化学光谱法测定   总被引:2,自引:0,他引:2  
采用以一定比例的HNO3和HCl为介质,使钨沉淀成钨酸与杂质分离,然后用碳粉吸附杂质再进行光谱测定的方法,对高纯钨(包括金属钨、三氧化钨、钨酸、钨酸铵)中15个杂质元素Fe、Ni、Cu、Mn、Al、V、Cr、Co、Ca、Ms、Pb、Sn、Bi、Cd、Be进行了测定,取得了理想的结果,测定下限可达(0.1~0.5)×10(-6)。  相似文献   

5.
利用电介质的平均能带模型计算了 REBa2Cu3O7(RE=Eu,Y)的化学键参数,得到 Cu(1)-O键的平均共价性为0.41, Cu(2)-O 键的平均共价性为 0.28.应用由共价性和极化率定义的化学环境因子计算了57Fe和119Sn在 REBa2Cu3O7中的 Mossbauer同质界能位移,确定了 57Fe在 EuBa2Cu3O7和 119Sn在 YBa2Cu3O7中的价态和占位情况  相似文献   

6.
用热分析法结合XRD、TEM研究了添加元素W、Nb对Fe76.5Cu1Si13.5B9非晶合金晶化行为的影响。结果表明,W或Nb的加入都降低了Fe-Cu-Si-B非晶合金反应的Avrami指数n;并且添加元素Nb更有利于该合金获得较小的a-Fe(Si)晶粒。  相似文献   

7.
稀土元素在金属材料中的一些物理化学作用   总被引:117,自引:0,他引:117  
杜挺 《金属学报》1997,33(1):69-77
针对不同金属溶液体系,采用了不同的实验方法,研究得到了铁液中Ce,Y,La,Nd,Sm分别与S,O,S+O,C,N,Sb,Sn Pb,P,Cu,Ti,Nb,V溶质元素,镍液中Ce,Y分别与S,O,S+O溶质元素,铜液中Ce,Y分别与S,O,S+O,Sn,Zn,Pb,Al,Si,Ti,Fe溶质元素,铝液中Ce分别与Mg,Ti,Mn,Zn,Fe,Sn,Pb,Ni,Cu,Si,S溶质元素构成的67个三元  相似文献   

8.
块体非晶态合金可以分为非铁基和铁基两大类 ,如下表所列 ,能制取非晶态最大直径 >5mm的非铁基(有色金属 )合金系有Mg Ln (Ni,Cu) ,Ln Al (Ni,Cu) ,Zr Al (Ni,Cu) ,含有Ti、Nb、Ta或Pd的Zr Al (Ni,Cu) ,还有Zr Ti Be Ni Cu、Pd Cu Ni P、Pd Cu Fe P、Ti Ni Cu Sn、Cu Zr Ti Y以及Cu Zr Ti Be系。另外 ,可形成非晶态最大直径 >2mm的铁基和钴基合金系 ,主要有Fe (Al,Ga) (P ,C ,B) ,含有Cr、Mo或Nb的Fe (Al,Ga) (P ,C …  相似文献   

9.
溴化碲分光光度法测定钛铝合金中微量碲   总被引:5,自引:0,他引:5  
溴化碲分光光度法应用于钛铝合金中微量碲的测定,取得了良好的效果。干扰试验表明,在所选定条件下,Zn,Mn,Mg,Pb,Mo,As,Y,Sn,Nb,Sb,P,Co,Ni,Ca,Si,Cd,Bi,Ce,Zr,W,V各1mg,Cu,Cr各0.1mgFe为0.2mg,对100μgTe的测定基本无干扰,TiAl基体的轻微干扰可以用同量的TiAl作参比而消除。分别对含Te0.100%和0.020%的两组合成试  相似文献   

10.
Al基和Fe基非晶合金热处理后的超细组织和力学性能用液体快淬法制作厚18μm、宽0.5mm的Fe73.5Cu1Nb3Si13.5B9(at%)及厚16μm、宽0.5mm的Al94.5Ni3.5Cu1.4Ce0.6(at%)非晶合金带。因两合金加热时都...  相似文献   

11.
In as-welded state, each region of 2219 aluminum alloy TIG-welded joint shows diff erent microstructure and microhardness due to the diff erent welding heat cycles and the resulting evolution of second phases. After the post-weld heat treatment, both the amount and the size of the eutectic structure or θ phases decreased. Correspondingly, both the Cu content in α-Al matrix and the microhardness increased to a similar level in each region of the joint, and the tensile strength of the entire joint was greatly improved. Post-weld heat treatment played the role of solid solution strengthening and aging strengthening. After the post-weld heat treatment, the weld performance became similar to other regions, but weld reinforcements lost their reinforcing eff ect on the weld and their existence was more of an adverse eff ect. The joint without weld reinforcements after the post-weld heat treatment had the optimal tensile properties, and the specimens randomly crack in the weld zone.  相似文献   

12.
After nearly two years' tense construction, the first phase of industrialized base of Shenyang Research Institute of Foundry (SRIF), located at the Tiexi Casting and Forging Industrial Park in the west of Tiexi District, has now been completed and formally put into operation.  相似文献   

13.
Institute of Process Engineering, Chinese Academy of Sciences, China, has proposed a method for oxidative leaching of chromite with potassium hydroxide. Understanding the mechanism of chromite decomposition, especially in the potassium hydroxide fusion, is important for the optimization of the operating parameters of the oxidative leaching process. A traditional thermodynamic method is proposed and the thermal decomposition and the reaction decomposition during the oxidative leaching of chromite with KOH and oxygen is discussed, which suggests that chromite is mainly destroyed by reactions with KOH and oxygen. Meanwhile, equilibrium of the main reactions of the above process was calculated at different temperatures and oxygen partial pressures. The stable zones of productions, namely, K2CrO4 and Fe2O3, increase with the decrease of temperature, which indicates that higher temperature is not beneficial to thermodynamic reactions. In addition, a comparison of the general alkali methods is carried out, and it is concluded that the KOH leaching process is thermodynamically superior to the conventional chromate production process.  相似文献   

14.
The effect of isochronal heat treatments for 1h on variation of damping, hardness and microstructural change of the magnesium wrought alloy AZ61 was investigated. Damping and hardness behaviour could be attributed to the evolution of precipitation process. The influence of precipitation on damping behaviour was explained in the framework of the dislocation string model of Granato and Lücke.  相似文献   

15.
The Lanthanum-doped bismuth ferrite–lead titanate compositions of 0.5(Bi LaxFe1-xO3)–0.5(Pb Ti O3)(x = 0.05,0.10,0.15,0.20)(BLxF1-x-PT) were prepared by mixed oxide method.Structural characterization was performed by X-ray diffraction and shows a tetragonal structure at room temperature.The lattice parameter c/a ratio decreases with increasing of La(x = 0.05–0.20) concentration of the composites.The effect of charge carrier/ion hopping mechanism,conductivity,relaxation process and impedance parameters was studied using an impedance analyzer in a wide frequency range(102–106Hz) at different temperatures.The nature of Nyquist plot confirms the presence of bulk effects only,and non-Debye type of relaxation processes occurs in the composites.The electrical modulus exhibits an important role of the hopping mechanism in the electrical transport process of the materials.The ac conductivity and dc conductivity of the materials were studied,and the activation energy found to be 0.81,0.77,0.76 and 0.74 e V for all compositions of x = 0.05–0.20 at different temperatures(200–300 °C).  相似文献   

16.
The orientation relationships(ORs)between the martensite and the retained austenite in low-and medium-carbon steels after quenching–partitioning–tempering process were studied in this work.The ORs in the studied steels are identified by selected-area electron diffraction(SAED)as either K–S or N–W ORs.Meanwhile,the ORs were also studied based on numerical fitting of electron backscatter diffraction data method suggested by Miyamoto.The simulated K–S and N–W ORs in the low-index directions generally do not well coincide with the experimental pole figure,which may be attributed to both the orientation spread from the ideal variant orientations and high symmetry of the low-index directions.However,the simulated results coincide well with experimental pole figures in the high-index directions{123}_(bcc).A modified method with simplicity based on Miyamoto’s work was proposed.The results indicate that the ORs determined by modified method are similar to those determined by Miyamoto’method,that is,the OR is near K–S OR for the low-carbon Q–P–T steel,and with the increase of carbon content,the OR is closer to N–W OR in medium-carbon Q–P–T steel.  相似文献   

17.
This work was to reveal the residual stress profile in electron beam welded Ti-6Al-4V alloy plates(50 mm thick) by using finite element and contour measurement methods.A three-dimensional finite element model of 50-mmthick titanium component was proposed,in which a column–cone combined heat source model was used to simulate the temperature field and a thermo-elastic–plastic model to analyze residual stress in a weld joint based on ABAQUS software.Considering the uncertainty of welding simulation,the computation was calibrated by experimental data of contour measurement method.Both test and simulated results show that residual stresses on the surface and inside the weld zone are significantly different and present a narrow and large gradient feature in the weld joint.The peak tensile stress exceeds the yield strength of base materials inside weld,which are distinctly different from residual stress of the thin Ti-6Al-4V alloy plates presented in references before.  相似文献   

18.
Silicon carbide nanoparticle-reinforced nickel-based composites(Ni–Si CNP),with a Si CNPcontent ranged from1 to 3.5 wt%,were prepared using mechanical alloying and spark plasma sintering.In addition,unreinforced pure nickel samples were also prepared for comparative purposes.To characterize the microstructural properties of both the unreinforced pure nickel and the Ni–Si CNPcomposites transmission electron microscopy(TEM) was used,while their mechanical behavior was investigated using the Vickers pyramid method for hardness measurements and a universal tensile testing machine for tensile tests.TEM results showed an array of dislocation lines decorated in the sintered pure nickel sample,whereas,for the Ni–Si CNPcomposites,the presence of nano-dispersed Si CNPand twinning crystals was observed.These homogeneously distributed Si CNPwere found located either within the matrix,between twins or on grain boundaries.For the Ni–Si CNPcomposites,coerced coarsening of the Si CNPassembly occurred with increasing Si CNPcontent.Furthermore,the grain sizes of the Ni–Si CNPcomposites were much finer than that of the unreinforced pure nickel,which was considered to be due to the composite ball milling process.In all cases,the Ni–Si CNPcomposites showed higher strengths and hardness values than the unreinforced pure nickel,likely due to a combination of dispersion strengthening(Orowan effects) and particle strengthening(Hall–Petch effects).For the Ni–Si CNPcomposites,the strength increased initially and then decreased as a function of Si CNPcontent,whereas their elongation percentages decreased linearly.Compared to all materials tested,the Ni–Si CNPcomposite containing 1.5% Si C was found more superior considering both their strength and plastic properties.  相似文献   

19.
A new method was introduced to achieve directional growth of Sn crystals. Microstructures in liquid(Pb)/liquid(Sn) diffusion couples were investigated under various static magnetic fields. Results show that the β-Sn crystals mainly reveal an irregular dendritic morphology without or with a relatively low static magnetic field(B0.3 T). When the magnetic field is increased to 0.5 T, the β-Sn dendrites close to the final stage of growth begin to show some directional character. With a further increase in the magnetic field to a higher level(0.8–5 T), the β-Sn dendrites have an enhanced directional growth character, but the dendrites show a certain deflection. As the magnetic field is increased to 12 T, the directional growth of the β-Sn dendrites in the center of the couple is severely destroyed. The mechanism of the directional growth of the β-Sn crystals and the deflection of the β-Sn crystals with the application of static magnetic field was tentatively discussed.  相似文献   

20.
韩磊 《腐蚀与防护》2015,36(1):84-90,94
综述了常见的电化学噪声数据处理方法,介绍了直流趋势剔除、统计分析、快速傅立叶变换(FFT)法计算功率谱密度(PSD)以及小波变换处理电化学噪声信号的基本过程,并阐释了各种数学处理及所得参数的物理意义。  相似文献   

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