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1.
铝及铝铁合金的加工软化机理   总被引:4,自引:0,他引:4  
研究了三种纯度的铝及其Al-2%Fe合金在室温轧制状态下的加工软化行为及软化机理,试验证明:99.996%Al当轧制率为80%以上时出现加工软化现象;99.96%Al和99.6%Al不发生软化,用99.996%Al配制的Al-2%Fe合金当轧制率为60%以上时出现加工软化;用99.96%Al配制的Al-2%Fe合金当轧制率为90%以上时出现加工软化;用99.6%Al配制的Al-2%Fe合金不发生加  相似文献   

2.
本文采用ICP-AES法测定了铝锂合金中硅、锆、铁、镁、铜,其测定含量在0.x% ̄0.0x%之间,对同一试样,分析方法的相对平均偏差为1.8% ̄5.0%,所有元素回收率在96% ̄104%之间,已应用于铝锂合金中各元素测定,结果令人满意。  相似文献   

3.
采用为生产紧固件按工业纯提供的热轧BT8M棒材(合金成分: 5.1%Al,0.96%Zr,4.11%Mo, 0.18%Si和1.08%Sn;成分含量均为重量百分比)进行了试验。在试验设备中于650℃温度下和在0.003%-0.7%浓度之内实现了定量渗氢.在由氢诱发的高温β-相冷却进程中,为了防止复合相转变,选择了低温氢化过程。在 POH-4衍射器中,实现了X射线分析.在Heo or-2型显微镜下进行了金相研究。而标准的机械试验在 10/90设备上和MK-30A冲击试验机上进行。 用淬火试验方法确定…  相似文献   

4.
针对小铁山铜铅锌多金属硫化矿全混合浮选工艺中存在的铜与铅锌分离困难,产品质量水平低,互含高,金属回收率较低等问题,进行了优先选铜工艺技术改造,在工业生产中取得了较好技术指标:铜精矿含铜18.96%,铜回收率41.64%。  相似文献   

5.
无镉银基合金在电子器件制造业中正逐步替代已广泛应用的Ag-12%CdO标准触点合金。用锌取代镉作为基材合金,再添加大量的锡和少量的铜。这样改进后的合金,经中间氧化后,具有比标准合金更好的电接触性能。  相似文献   

6.
协同系数补偿的动力学方法用于钼和钨同时测定的研究   总被引:1,自引:0,他引:1  
以I3-淀粉配合物为指示剂,用停流FIA光度法研究了钼(VI)和钨(VI)对H2O2-I氧化还原反应体系的协同催化效应,并定义了协同催化系数D以表示这种协同作用的大小。将此系数引入到停流FIA-动力学体系多组份同时测定的方法中,可有效地补偿吸光度对加和性的偏离,并可降低检出限。用本法测定钼(Ⅵ)和钨(Ⅵ)的线性范围分别为0~1.1μg·ml-1和0~2.0μg·ml-1,而未补偿时则分别为0~0.6μg·ml-1和0~0.8μg·ml-1。测定了钢样及模拟样品中的用和钨含量,结果满意。钼、钨的回收率分别为97.3%~102.8%,96.5%~102.1%,相对标准偏差RSD分别为2.1%~2.9%,2.3%~3.4%。  相似文献   

7.
选冶联合流程回收铜银金的工艺   总被引:4,自引:2,他引:2  
采用DX 低碱度抑制剂, 用NaOH 调节pH, 在pH= 9 ~10 的范围内浮铜抑硫, 使混合精矿中的有价金属与黄铁矿分离, 再选精矿产率20 % ~30 % , 尾矿含金低于3 .0 g/t。在较低的压力下( 氧压0 .4 ~0 .6 MPa) 对所得精矿进行氧压氨浸, 使硫转化为硫酸铵, 铜进入溶液, 金银留在浸渣中。分选中金、银、铜回收率分别为95 % ,90 % 和85 % ; 分选条件为pH= 9 .5 , 捕收剂用量200 g/t, DX 抑制剂3kg/t。低压氨浸铜浸出率为95 % , 浸出压力0 .5 MPa, 温度120 ℃, 时间3 h , 氨浓度45 g/L。氰化浸出金、银浸出率为97 % 和95 % , 置换率99 % 和98 % 。金、银、铜总回收率分别为94 % ,84 % 和81 % 。  相似文献   

8.
ICP—AES法同时测定银合金中的锡铜镧   总被引:2,自引:0,他引:2  
李立新  冯忠 《贵金属》1998,19(1):33-35
用ICP-AES法同时测定合金组分Sn、Cu和La,盐酸沉淀Ag,银基体不干扰测定,标准溶液中不须加入银与合金试样匹配。合成样实验回收率95%~105%;相对标准偏差Sn、Cu<0.5%、La<1%,测定范围以基体含量浓度2mg/ml计,Sn11%~45%、Cu7%~30%、La0.05%~0.15%。  相似文献   

9.
含微量卤化银废水回收银的工艺   总被引:1,自引:0,他引:1  
杨茂才  刘正华 《贵金属》1997,18(3):23-27
用多种铁盐处理含卤化银废水沉淀银及制取纯银,讨论其反应原理,技术条件及试验结果,全流程Ag回收率≥97%,产品Ag纯度≥99.9%。  相似文献   

10.
用机械合金化方法制备Ni—Al系金属间化合物   总被引:8,自引:1,他引:7  
李谷松  丁炳哲 《金属学报》1994,30(2):B091-B096
用球磨机分别对Ni-50at.-%Al和Ni-25at.-%Al混合粉末进行机械合金化,并对Ni3Al预合金粉末进行高能球磨,观察了粉末的金相组织,测定了粉末的硬度、平均直径和晶粒尺寸,并作了XRD物相分析。结果表明,经3h研磨,Ni-50at.-%Al混合粉末变成NiAl金属间化合物,其晶粒直径约5nm;经5h机械球磨,Ni-25at.-%Al混合粉末成为无序的亚稳定Ni固溶体,而Ni3Al预合  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.
吴玉梅  熊晓云  靳蓉  孙敬民  杨林  罗晓星 《金属学报》2005,10(10):1100-1103
目的: 观察本实验室合成的一种治疗阿尔茨海默氏症(AD)的药物(1-二甲基磷酰基-2, 2, 2 -三氯)-乙基-1-醇烟酸醋(NMF),对体外培养的皮层神经细胞活性的影响以及对海人藻酸(KA)所致的神经损伤的保护作用。方法: 采用体外培养皮层神经元的方法,解剖分离 15 d胚胎小鼠皮层神经细胞, 接种于 96孔板,48 h 后加药并培养 72 h,以 MIT 法 观察 NMF 对小鼠皮层神经细胞活性的影响;同时将接种于 24 孔板的细胞预先给予 NMF,d 3 时加或不加KA处理后,以台盼蓝染色鉴别并计数死、活细胞,可得出细胞的存活率。结果: NMF 明显促进胎鼠皮层神经元活性,其中 NMF1、0. 1、10nmol·L-1促进神经元活性增殖率分别高达 34.7%、37.4%、36. 7%, NMF 明显促进正常胎鼠皮层神经元存活卒,与对照组比较,10nmol·L-1 NMF 对皮层神经元的存活率分别提高 39.3%、73.5%。 NMF能显著 对抗 KA 所致的神经元损伤,与 KA 损伤组相比, NMF0.1、10、10nmol·L-1对损伤皮层神经元的保护率分别为 77.30%、80.10%、84.15%。结论: NMF 明 显促进胎鼠皮层神经元的洁性、提高正常皮层神经元,的存活卒,并能有效地保护KA所致的神经元损伤,提示 NMF 是一种很有潜力的治疗 AD 的药物。  相似文献   

14.
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   

15.
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   

16.
Coherent second phase often exhibits anisotropic morphology with specifi c orientations with respect to both the second and the matrix phases. As a key feature of microstructure, the morphology of the coherent particles is essential for understanding the second-phase strengthening eff ect in various industrial alloys. This letter reports anisotropic growth of coherent ferrite from austenite matrix in pure iron based on molecular dynamics simulation. We found that the ferrite grain tends to grow into an elongated plate-like shape, independent of its initial confi guration. The fi nal shape of the ferrite is closely related to the misfi t between the two phases, with the longest direction and the broad facet of the plate being, respectively, consistent with the best matching direction and the best matching plane calculated via the Burgers vector content(BVC) method. The strain energy calculation in the framework of Eshelby's inclusion theory verifi es that the simulated orientation of the coherent ferrite is energetically favorable. It is anticipated that the BVC method will be applicable in analysis of anisotropic growth and morphology of coherent second phase in other phase transformation systems.  相似文献   

17.
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   

18.
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   

19.
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   

20.
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   

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