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1.
充芯连铸铜包铝棒坯工艺参数对表面质量的影响 总被引:5,自引:3,他引:2
在自制的连铸设备上,通过工艺参数的合理匹配,成功地制备出外层为铜内层为铝,外径为40mm、铜壁厚为8mm、长为80cm的铜包铝棒坯。试验发现铜液的熔化温度、结晶器水冷铜套与石墨衬套的接触长度、连铸速度、二次冷却水的位置和流量对固液界面、铜管的表面质量以及复合界面铜铝的相互扩散都有很大的影响。合理匹配可使固液界面位置调整到离结晶器出口端5~10mm处,复合棒坯表面光洁、复合良好,经过挤压与拉拔,可以制成不同直径的铜包铝复合线。 相似文献
2.
在充芯连铸工艺原理的基础上,提出了制备外径为准12 mm,内径为准8 mm小尺寸铜包铝连铸复合坯的新工艺方法,即对铜液进行加压进而改善铜液冷却连铸成形的质量,成功制备了合格的铜包铝连铸复合坯。在现有的充芯连铸机上,自行设计了本实验装置,研究了Cu和Al的加热温度,Cu液充压的压力,二冷方式、强度,连铸复合坯的连铸速度等因素对充芯连铸成形的影响规律。结果表明:在铜的温度为1320℃、铝的温度为740℃、结晶器的冷却水量为4.6 L/min、二冷水量为0.67 L/min、铜液的充气压力为0.05 MPa、二冷位置离结晶器出口为50 mm、连铸复合坯的连铸速度为25 mm/min时可以连铸出铜包铝复合坯,其表面质量光滑,铜铝的复合质量较好。 相似文献
3.
矩形断面铜包铝复合材料的水平连铸直接复合成形 总被引:2,自引:0,他引:2
制备断面尺寸为50 mm×30 mm、铜包覆层厚度为3 mm的矩形断面铜包铝复合材料,研究结晶器长度、拉坯速度、芯管长度和一次冷却水流量对矩形断面铜包铝复合材料水平连铸直接复合成形过程的影响。结果表明:当连铸结晶器长度为150 mm、芯管长度为125 mm时,较为合理的拉坯速度范围为75~90 mm/min;当拉坯速度过慢时,铝液的填充不连续,导致芯部铝的收缩或冷隔等缺陷;当拉坯速度过快时,铜铝界面反应严重;当拉坯速度为75 mm/min时,合理的一次冷却水流量为700 L/h,一次冷却水流量大于1 000 L/h导致铝液填充不连续,一次冷却水流量小于400 L/h则导致铜铝界面反应加剧。通过检测芯管出口位置处的石墨内衬温度变化可有效监控铝液的填充行为以及连铸过程的稳定性。 相似文献
4.
《中国有色金属学报》2017,(3)
以100mm×100mm大断面铜包铝棒坯为对象,建立棒坯连铸复合成形的数值模型,确定模型的边界条件,并通过设计的实验验证数值模型边界条件的准确性。基于验证的边界条件,采用ProCast软件对铜包铝棒坯立式连铸复合成形过程的稳态温度场进行数值模拟,得到了各工艺参数对连铸过程的影响规律,给出了工艺参数的调控策略和合理范围。结果表明,制备100mm×100mm大断面铜包铝铸坯的合理工艺参数范围为:在保持铜液温度1250℃的条件下,铝液铸造温度为760~790℃;一冷水流量为1600~2000L/h;二冷水流量为900~1100 L/h;二冷水距结晶器石墨套出口距离为20 mm;拉坯速度为80~100mm/min。 相似文献
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设计和制造了一台制备铜包铝复合扁排的立式充芯连铸试验设备,该设备的特点是在高度方向上设置上下两个加热坩埚分别熔化铜和铝;外层铜管在结晶器中首先形成,铝液随之通过充芯管充填到铜管中,铜、铝界面通过互扩散实现冶金结合.利用此设备,成功地连铸出铜层厚度为2 mm,芯部铝厚度为10 mm,宽为60 mm的铜包铝复合扁排. 相似文献
7.
双结晶器连铸铜-锌铝合金双金属复合材料 总被引:4,自引:0,他引:4
设计和制造了1台双金属双结晶器连续铸造试验机,其特征是:(1)结晶器为水冷铜套内衬石墨套;(2)结晶器上面连接可控制温度的熔化保温炉;(3)在高度方向上设置一高一低,直径一小一大的结晶器,在此试验机上,成功地连续铸造出芯部直径φ20mm的铜合金,外层厚度为10mm的锌铝合金的双金属复合圆棒,通过测试和分析此复合圆棒的宏观和微观的复合断面,化学成分分布,复合界面的剪切强度,证明此连续铸造试验机可以制备出复合良好的铜-锌铝双金属棒。 相似文献
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水平连铸直接复合成形铜包铝复合材料的组织与性能 总被引:1,自引:0,他引:1
研究了水平连铸直接复合成形铜包铝棒材的制备工艺和组织性能及退火处理对界面层塑性的影响。结果表明,采用水平连铸直接复合成形法在芯管长度L=210mm、铜铸造温度tCu=1230℃、铝铸造温度tAl=770~850℃、一次冷却水流量Q1=600L/h、二次冷却水流量Q2=600~800L/h、平均拉坯速度v=60~87mm/min的可行工艺窗口下能够制备出直径为30mm、铜包覆层厚度为3mm、质量良好的铜包铝复合棒材。在退火温度为530℃、保温时间为50min的工艺条件下,退火处理后可明显改善界面层的塑性。铜包铝复合棒材的抗拉强度和伸长率分别为80~94MPa和18%~31%。 相似文献
11.
Deng-Kui Zhang Guo-Qing Wang Ai-Ping Wu Ji-Guo Shan Yue Zhao Tian-Yi Zhao Dan-Yang Meng Jian-Ling Song Zhong-Ping Zhang 《金属学报(英文版)》2019,32(6):684-694
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 《中国铸造》2008,5(1):63-64
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.
Z. Sun S.L. Zheng Y. Zhang 《金属学报(英文版)》2007,20(3):187-192
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.
R. González-Martínez 《金属学报(英文版)》2007,20(4):235-240
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.
Chao Yang He-Fei Huang Massey de los Reyes Long Yan Xing-Tai Zhou Tian Xia De-Liang Zhang 《金属学报(英文版)》2015,28(7):809
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
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Lei Li Bo Xu Wei-Ping Tong Hui Zhang Chun-Yan Ban Li-Zi He Zhi-Hao Zhao Yu-Bo Zuo Qing-Feng Zhu Jian-Zhong Cui 《金属学报(英文版)》2015,28(6):725
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.
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