Effects of annealing process on electrical conductivity and mechanical property of Cu-Te alloys

1 Introduction Pure copper and copper alloys are widely used due to the high electrical conductivity, high heat transfer, corrosion resistance and excellent formability[1-5]. But the strength of pure copper is low and the strength gained during cold worki…     

Cu-Te合金的光学金相显微组织分析与研究

采用不同的侵蚀剂侵蚀试样,结合光镜和扫描电镜分析揭示铜碲合金在不同侵蚀剂侵蚀下显示的显微组织,特别是合金中第二相的显微组织形貌以及三维组织的空间形貌特征,为高性能铜合金研究提供参考。     

Cu-Te合金的光学金相显微组织分析与研究

采用不同的侵蚀剂侵蚀试样，结合光镜和扫描电镜分析揭示铜碲合金在不同侵蚀剂侵蚀下显示的显微组织，特别是合金中第二相的显微组织形貌以及三维组织的空间形貌特征，为高性能铜合金研究提供参考。     

合金焊丝退火工艺的改进

传统工艺退火处理后的合金低碳钢焊丝ER110S,在后续的拉拔加工中,加工硬化导致经常断丝;金相分析发现,退火后的原材料组织中存在大量不连续分布的贝氏体组织和弥散分布的碳化物.应用DSC分析重新确定该材料的相变温度点Ac_1、Ac_3,通过完全退火和再结晶退火工艺实验,得出700℃保温15h、随炉冷却到300℃出炉空冷的再结晶退火工艺.能够满足焊丝拉拔加工的力学性能要求.     

轧制和退火态的Mg-Y-Zr-xNd合金的组织和力学性能

通过光学显微组织(OM),扫描电子显微镜(SEM),X射线衍射(XRD),电子背散射衍射(EBSD)和拉伸试验研究了不同热处理条件下Mg-5Y-0.6Zr-xNd (x = 0, 0.5和1wt.％) 合金的组织和力学性能。结果表明,随着Nd含量的增加,第二相Mg24Y5和Mg14Nd2Y (β)在基体中的含量增加。添加少量Nd可以降低α-Mg的堆垛层错能,促进热轧过程中的动态再结晶。随着Nd含量的增加,静态再结晶的体积分数明显增加。退火处理后Mg-5Y-0.6Zr-0Nd合金的平均晶粒尺寸可细化至3.73μm。轧制合金的抗拉强度随着Nd的增加而增加,而伸长率则表现出相反的变化趋势。含有1.01wt.％Nd的轧制合金具有优良的机械性能,其拉伸强度,屈服强度和伸长率分别为336MPa,278MPa和16.3％。在微观结构观察的基础上,讨论了力学性能的变化。     

退火处理对超细晶Cu-Cr合金组织和性能的影响

对Cu-0．4Cr合金进行ECAP（等通道转角挤压）8道次的挤压，得到晶粒尺寸为500nm的等轴晶组织，然后在电阻炉内进行退火试验，通过对ECAP细晶的铜铬合金在473～873K退火1h，分析合金的组织和性能，研究该合金的硬度和导电性能。研究发现，弥散的Cr可以有效地阻止合金的晶粒长大；723K退火后，Cu-0．4Cr合金的电导率和硬度分别可达80．3％IACS和210．9HV，并有较好的综合性能。     

铜碲合金时效工艺的研究

研究了铜碲合金的时效工艺，用扫描电镜(SEM)和能谱(EDS)分析了析出相的形貌与组成，进而研究了时效工艺对其电性能及力学性能的影响。研究表明：时效过程中Te以第二相形式析出(Cu2Te)；随时效温度的升高、时效时间的延长，时效态的铜碲合金位错密度降低，晶粒长大，第二相析出充分，因而电阻率单调下降；但由于时效析出与再结晶的交互作用，其抗拉强度出现波动，存在1个峰值；综合性能以420℃下时效6h较好。     

Al-Zn-Mg-Cu-Sc合金的退火再结晶机制研究

制备了一种含Sc的Al-Zn-Mg-Cu合金,采用光学显微镜、扫描电镜、透射电镜技术,运用晶界和晶粒拓扑理论研究、分析了该合金的再结晶组织和规律.结果表明:合金中添加0.15%Sc,可以明显提高再结晶温度.在总变形量一定的条件下,随应变速率增加,合金再结晶过程加快.变形局部化所形成的强剪切变形区,可以看作是没有溶质和溶剂原子的"真空"区域.固溶处理时,该区以界面弓出机制进行再结晶形核,以亚晶吞并机制长大.进入"真空"区域内的溶质和溶剂原子,通过组装过程完成"二次晶体"的重建.淬火的"二次晶体"中保留有大量的空位,溶质原子在空位处偏聚,并通过吸收周围的溶质原子长大.     

形变Cu-4Al合金再结晶动力学

测试了Cu-4Al合金经50％变形后在不同温度下再结晶动力学曲线，并根据公式G＝G0exp(-Q/RT)计算出再结晶激活能。     

Effect of Zr content on quench sensitivity of AlZnMgCu alloys

The effect of Zr content on quench sensitivity of AlZnMgCu alloys was investigated by mechanical properties testing and microstructure observations. The results show that with the increase of Zr the quench sensitivity relative to hardness and strength increases, while that relative to elongation decreases. From hardness and strength viewpoints, the low quench sensitivity is observed for the Zr-free and 0.05% Zr-containing alloys, which is quite quench sensitive from the ductility viewpoint. The largest quench sensitivity relative to hardness and strength is observed for 0.1% Zr-containing alloy, this is mainly due to large amount of high angle grain boundaries and incoherent Al3Zr dispersoids caused by recrystallization, which may efficiently promote heterogeneous precipitation during air quenching. More than 0.05% Zr can significantly decrease the quench sensitivity relative to ductility, which can be primarily attributed to recrystallization inhibiting and grain refining effects of Zr.     

Textural inspection of recrystallization process under bimodal particle distribution in pure Al-Mn alloy

1INTRODUCTIONAnnealingadeformedmaterialcontaininglargeparticleswil1leadto,duetothelargemis-orientationandthehighstoredenergy,preferrednucleationaroundparticles,thesocalledparticlestimulatednucIeation(PSN).Themicr0struc-tureandthetexturerelatedwithPSNmayberathercomplicatedsince,firstly,PSNisinflu-encedbythesize,distributionandvolumefrac-tionofparticlesandbyannealingtemperatures,andsecondly,notonlyPSNbutalsothenucle-ationatgrainboundariescantakeplace.Where-asannealingathightemperatureo…     

Evaluating electrochemical behaviour of recrystallized titanium alloys in Ringer's solution

By anodic potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques, the effect of recrystallization on the corrosion and electrochemical behaviour of Ti12Mo and Ti12Mo5Ta alloys was studied. Aerated Ringer's solution was employed as electrolyte solution at 37 °C. The pH was 6.9 and adjusted to 2.5 simulating the disease state. The results show excellent corrosion resistance for recrystallized Ti12Mo and Ti12Mo5Ta alloys, corroborated by high values of polarization resistance and low values of passive current density. Recrystallized structure rendered the Ti12Mo and Ti12Mo5Ta alloys extremely corrosion resistant.     

Corrosion behavior of hypoeutectic Al-Cu alloys in H2SO4 and NaC1 solutions

alloys.     

Corrosion behavior of hypoeutectic Al-Cu alloys in H_2SO_4 and NaCl solutions

The aim of this work was to evaluate the electrochemical behaviour of hypoeutectic Al-Cu alloys immersed in two different solutions containing sulphate and chloride ions,respectively.The influence of Al2Cu associated to the dendritic arm spacing on the general corrosion resistance of such alloys is analysed.The typical microstruc-tural pattern was examined by using scanning electron microscope.The corrosion tests were performed in both 0.5 M sulphuric acid and 0.5 M NaCl solutions at 25°C by using an electr...     

TP2铜管再结晶退火试验

通过对TP2铜管在不同退火温度和不同保温时间进行再结晶退火试验,结合再结晶动力学和晶粒长大动力学,分析了再结晶体积分数和平均晶粒尺寸的变化规律.结果表明,随着退火温度的提高,TP2铜管发生再结晶过程的开始时刻提前,完成再结晶所需要的时间缩短,随后的晶粒长大过程相对延长,平均晶粒尺寸增加;在500 ℃时,随着退火时间的延长,再结晶体积分数持续增加,当平均晶粒尺寸增大到20.2 μm后趋于稳定.