铜工夹具设计

介绍了一种适用大批量加工铜工的专用夹具，结构简单，在各机床间具有较好的互换性能，能提高零件在电火花加工时的定位精度，并减少装夹时间，提高产品精度和生产率，节约铜工材料。本文对该夹具进行了结构分析，并说明了夹具的原理与用途。

昆明冶炼厂15000t/a铜工程粗炼投产

昆明冶炼厂15000t/a电铜改扩建工程自1993年8月开工以来,经过近两年来的建设,粗炼系统已于1994年8月3日投料试生产,到8月6日上午已产出粗铜30t。该工程的建成投产,将为昆明冶炼厂调整产品结构,增加生产能力,实现产值、利润翻番奠定基础。 该工程粗炼系统计划投资6530万元。

基于UG8.5手机外壳的五轴数控加工

分析了五轴数控加工的工艺流程,通过以手机外壳模型为加工对象进行了五轴数控加工,对手机外壳的结构工艺性分析,手机拆电极设计出的立体铜工,并成功用于生产,对今后模具加工铜工极大的方便。

电动按摩洗脚盆电器零部件热压机的设计

本文论述了一种特殊电动按摩洗脚盆电器零配件热压机的设计方法．并说明了该机的构造及功能和特点。

Influence of solidification mode on pore structure of directionally solidified porous Cu-Mn alloy

By the directional solidification of metal-gas eutectic method（GASAR）,porous Cu-Mn alloy with oriented pores was fabricated successfully.The variation of pore structure was studied by experiments.The results show that the pore structure is primarily dependent on the solidification mode（planar,columnar cellular,columnar dendritic,equiaxed dendritic）,which is controlled by the solidification process.By numerical simulation,it is noted that along with solidification,the solidification mode of the alloy transforms from cellular to columnar dendritic and finally to equiaxed dendritic.Through increasing melt temperature and mold preheating,the range of equiaxed dendrite could be decreased,which helps to extend the region of oriented pore structure.

某厂枪弹制造作业人员肝癌死亡队列研究

对某厂枪弹制造作业人员肝癌死亡进行了回顾性队列研究。观察组１９２８人，观察２７７８２人年，对照组６７６人，观察９７０１人年，失访率均低于５％。观察期从１９８１年１月１日至１９９５年１２月３１日。以哈市一般人群为参比标准时，观察组男性肝癌标化死亡比（ＳＭＲ）为１７９（９５％ＣＩ１１３～２６８）。与对照组比，年龄分层相对危险度（ＲＲＴ）为１５４；观察组中熔铜工男性ＳＭＲ４４８（９５％ＣＩ１６４～９７５），ＲＲＴ为４５０（Ｐ＜００１）。观察组饮酒男性ＳＭＲ是２３９（９５％ＣＩ１３１～４０２），对照组不饮酒男性１例肝癌死亡。调查结果提示：观察组熔铜工接触的职业有害因素与饮酒可能对该队列肝癌死亡超量有协同作用。

Evaluation and simulation analysis of China's copper security evolution trajectory

Copper metal is one important raw material of national economy, and its security is tightly linked with industrialization process. A comprehensive security evaluation index system, including three first class indicators, nine second class indicators and fourteen third class indicators, was constructed based on the pressure-state-response （PSR） model. And efficacy coeff^cient method was adopted in dimensionless treatment and entropy method was used to obtain the weight. Then, the data of China＇s copper from 1992 to 2011 were studied and collected. By processing these data, a comprehensive safety index of China＇s copper was got. The results showed that the comprehensive safety index of China＇s copper rose from its low point. The safety pressure state of China＇s copper was improved. The safety state of China＇s copper continued to be tight. The response state continued to rise. The overall situation of China＇s copper safety was improving, but still not optimistic.

Parameters optimization of electroless deposition of Cu on Cr-coated diamond

Electroless copper plating on diamond particles precoated with 1%Cr was carried out to evaluate the effects of various experimental parameters on coating quality and deposition rate to obtain the optimized reaction parameters. The formulated samples under optimized parameters were characterized by X-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy, X-ray photoelectron spectra and optical microscopy. The best parameters, where uniform and maximum coating thickness was achieved, are etching with 20%NaOH for 30 min, sensitization and activation with SnCl2 and PdCl2 for 5 and 20 min, respectively. The composition of the copper solution bath was 16 g/L CuSO4＆#183;5H2O, 35 mL/L formaldehyde （HCHO）, 23 g/L KNaC4H4O6 at 60 ℃, pH=13 and stirring at （350±15） r/min under ultrasonication.

Development of processing windows for friction stir spot welding of aluminium Al5052/copper C27200 dissimilar materials

Friction stir spot welding technique was used to join dissimilar combinations of aluminium alloy(Al5052)with copperalloy(C27200)and friction stir spot welding windows such as tool rotational speed–dwell time and tool rotational speed?plungedepth diagrams for effective joining of these materials were developed.Using a central composite design model,empirical relationswere developed to predict the changes in tensile shear failure load values and interface hardness of the joints with three processparameters such as tool rotational speed,plunge depth and dwell time.The adequacy of the developed model was verified usingANOVA analysis at95%confidence level.Response surface methodology was used to optimize the developed model to maximizetensile strength and minimize interface hardness.A high tensile shear failure load value of3850N and low interface hardness valueof HV81was observed for joints made under optimum conditions,and validation experiments confirmed the high predictability ofthe developed model with error less than2%.The operating windows developed shall act as reference maps for future designengineers in choosing appropriate friction stir spot welding process parameter values to obtain good joints.

Multiphase equilibrium modeling of oxygen bottom-blown copper smelting process

A computational thermodynamics model for the oxygen bottom-blown copper smelting process(Shuikoushan,SKS process)was established,based on the SKS smelting characteristics and theory of Gibbs free energy minimization.The calculated results of the model show that,under the given stable production condition,the contents of Cu,Fe and S in matte are71.08%,7.15%and17.51%,and the contents of Fe,SiO2and Cu in slag are42.17%,25.05%and3.16%.The calculated fractional distributions of minor elements among gas,slag and matte phases are As82.69%,11.22%,6.09%,Sb16.57%,70.63%,12.80%,Bi68.93%,11.30%,19.77%,Pb19.70%,24.75%,55.55%and Zn17.94%,64.28%,17.79%,respectively.The calculated results of the multiphase equilibrium model agree well with the actual industrial production data,indicating that the credibility of the model is validated.Therefore,the model could be used to monitor and optimize the industrial operations of SKS process.

Interface repairing for AA5083/T2 copper explosive composite plate by friction stir processing

Multi-pass friction stir processing(M-FSP)was performed to repair the interface defects of AA5083/T2 copper explosive composite plates.The interface morphology and its bonding mechanism were explored.The results show that higher rotation speed and lower transverse speed produce more heat generated during FSP.The defect-free and good mechanical properties of the AA5083/T2 copper composite plate can be obtained under the condition of the rotation speed of 1200 r/min,the transverse speed of 30 mm/min and the overlap of 2/24.Moreover,M-FSP changes the interface bonding mechanism from metallurgical bonding to vortex connection,improving the bonding strength of composite plate,which can guarantee the repairing quality of composite plates.

Mechanical activation of natural chalcopyrite for improving heterogeneous Fenton degradation of tetracycline

Natural minerals receive growing attention as inexpensive, green, and efficient catalysts for degradation of organic pollutants. Mechanical activation of natural chalcopyrite was conducted for improving the catalytic performance.Tetracycline degradation was evaluated in the presence of hydrogen peroxide and mechanically activated chalcopyrite.Tetracycline degradation at 100 min is 55.52%(Chp10), 68.97%(Chp30), 77.79%(Chp60), and 86.43%(Chp120),respectively, and the rate constant of pseudo-first-order kinetics is 0.0079, 0.0109, 0.0137 and 0.0192 min^(-1), respectively.Chalcopyrite samples were examined by multiple characterizations. Mechanical activation of natural chalcopyrite induces the decline of particle size and slight increase of surface area, smaller grain size, lattice strain, and partial sulfur oxidation. The relationship between catalytic activity and property change manifests that the improved catalytic ability is mainly ascribed to the increase of surface area and surface oxidation induced by mechanical activation. This work provides novel insights into the improvement of catalytic performance of natural minerals by mechanical activation.

Effects of processing parameters on corrosion properties of dissimilar friction stir welds of aluminium and copper

The influence of friction stir welding processing parameters on dissimilar joints conducted between aluminium alloy （AA5754） and commercially pure copper （C11000） was studied. The welds were produced by varying the rotational speed from 600 to 1200 r/min and the feed rate from 50 to 300 mm/min. The resulting microstructure and the corrosion properties of the welds produced were studied. It was found that the joint interfacial regions of the welds were characterized by interlayers of aluminium and copper. The corrosion tests revealed that the corrosion resistance of the welds was improved as the rotational speed was increased. The corrosion rates of the welds compared to the base metals were improved compared with Cu and decreased slightly compared with the aluminium alloy. The lowest corrosion rate was obtained at welds produced at rotational speed of 950 r/min and feed rate of 300 mm/min which corresponds to a weld produced at a low heat input.

Gas tungsten arc welding of CP-copper to 304 stainless steel using different filler materials

The dissimilar joining of CP-copper to 304 stainless steel was performed by gas tungsten arc welding process using different filler materials. The results indicated the formation of defect free joint by using copper filler material. But, the presence of some defects like solidification crack and lack of fusion caused decreasing tensile strength of other joints. In the optimum conditions, the tensile strength of the joint was 96% of the weaker material. Also, this joint was bent till to 180° without any macroscopic defects like separation, tearing or fracture. It was concluded that copper is a new and good candidate for gas tungsten arc welding of copper to 304 stainless steel.

Control of Pinhole Defects Formation in Semi-flexible Coaxial Cable by Vertical Tin-Plating Process

Holistic tin-plating on the outer conductor is one of the key processes in the manufacture of semi-flexible coaxial cable, which is widely applied to the third generation (3G) mobile communication system. However, in the traditional horizontal tin-plating process, disadvantages such as the pinhole defects and low productivity effect cannot be avoided. In this paper, a vertical tin-plating process was proposed to reduce the pinhole defects and improve the tincoating quality. Compared with the traditional horizontal tin-plating process, the immersion length was reduced from 300-400 mm to 10-100 mm and the tin-plating time was reduced from 7 s to 3 s in the proposed method. The experimental results indicate that immersion length and time are key parameters for the tin-plating quality. With this new tin-plating process, the experimental results show that the pinhole defects can be eliminated effectively by controlling the immersion depth below 100 mm and tin-plating time at 3 s. The thickness of tin-coating increased from not more than 5 μm to 12.3 μm with the proposed vertical tin-plating process. Meanwhile, the thickness of the intermetallic compounds (IMCs) layer between the tin-coating and copper wires was reduced from 3.26 μm to 0.62 μm if the immersion time decreased from 30 s to 1 s. Besides, a self-developed flux, which possesses a boiling point or decomposed temperature of active components over 300℃, exhibits a better efficiency in reducing the pinhole formation.

Recovery prediction of copper oxide ore column leaching by hybrid neural genetic algorithm

The artificial neural network(ANN)and hybrid of artificial neural network and genetic algorithm(GANN)were appliedto predict the optimized conditions of column leaching of copper oxide ore with relations of input and output data.The leachingexperiments were performed in three columns with the heights of2,4and6m and in particle size of<25.4and<50.8mm.Theeffects of different operating parameters such as column height,particle size,acid flow rate and leaching time were studied tooptimize the conditions to achieve the maximum recovery of copper using column leaching in pilot scale.It was found that therecovery increased with increasing the acid flow rate and leaching time and decreasing particle size and column height.Theefficiency of GANN and ANN algorithms was compared with each other.The results showed that GANN is more efficient than ANNin predicting copper recovery.The proposed model can be used to predict the Cu recovery with a reasonable error.

Industrial experiment of copper electrolyte purification by copper arsenite

Copper electrolyte was purified by copper arsenite that was prepared with As2O3.And electrolysis experiments of purified electrolyte were carried out at 235 and 305 A/m2,respectively.The results show that the yield of copper arsenite is up to 98.64% when the molar ratio of Cu to As is 1.5 in the preparation of copper arsenite.The removal rates of Sb and Bi reach 74.11% and 65.60% respectively after copper arsenite is added in electrolyte.The concentrations of As,Sb and Bi in electrolyte nearly remain constant during electrolysis of 13 d.The appearances of cathode copper obtained at 235 and 305 A/m2 are slippery and even,and the qualification rate is 100% according to the Chinese standard of high-pure cathode copper(GB/T467-97).

Electroless Plating of Carbon Nanotubes with Copper

A simple chemical method was employed to coat carbon nanotubes with a layer of copper. Due to the hydrophobic nature, large surface curvature, small diameter and large aspect ratio, it is difficult to gain continuous electroless plating layer on the surface of carbon nanotubes. In this paper, a series methods (oxidization, sensitization and activation) are used to add active sites before electroless plating, and the adjustment of the traditional composition of copper electroless plating bath and operating condition can decelerate electroless plating rate. The samples before and after coating were analyzed using transmission electron microscopy and energy-dispersive X-ray spectroscopy. The results showed that the surface of carbon nanotubes was successfully coated with continuous layer of copper, which lays a good foundation for applying carbon nanotubes in composites.

Microstructural evaluation and tribological properties of underwater friction stir processed CP-copper and its alloy

Underwater friction stir processing was performed on commercially pure copper with a purity of 99.8% and a copper-zinc alloy(brass). The tool was made of tungsten carbide in the threaded cone form. Friction stir processing was performed at a tool rotational speed of 1800 r/min and a tool transverse speed of 4 mm/min while the samples were immersed in a water tank with a water circulation system. In order to evaluate the effect of the number of process passes on the microstructure and mechanical properties of the samples, this process was continued for up to 6 passes. Microscopic studies using light microscopy on commercially pure copper samples show significant decrease in grain size. Likewise, the hardness of the cross-sectional area shows an increase more than the base metal. The X-ray diffraction pattern of the underwater friction stir processed samples in comparison to that of the base metal exhibits shorter and wider peaks, while the background of the pattern is increased. The sum of these factors represents the formation of an amorphous/ultrafine grained structure. Also, the wear behavior of the samples was investigated by means of pin-on-disk method and the results show that the friction coefficient of processed samples is decreased compared to that of the base metal. The results of wear and hardness tests show that the underwater friction stir processing can significantly improve the wear resistance and hardness of commercially pure copper and brass.

Comparative studies on hydrometallurgical treatment of smelted low-grade electronic scraps for selective copper recovery

A comparison of three hydrometallurgical methods for selective recovery of copper from low-grade electric and electronic wastes was reported. Scraps were smelted to produce Cu？Zn？Sn？Ag alloy. Multiphase material was analyzed by SEM？EDS and XRD. The alloy was dissolved anodically with simultaneous metal electrodeposition using ammoniacal and sulfuric acid solutions or leached in ammonia？ammonium sulfate solution and then copper electrowinning was carried out. This resulted in the separation of metals, where lead, silver and tin accumulated mainly in the slimes, while copper was transferred to the electrolyte and then recovered on the cathode. The best conditions of the alloy treatment were obtained in the sulfuric acid, where the final product was metal of high purity （99% Cu） at the current efficiency of 90%. Ammoniacal leaching of the alloy led to the accumulation of copper ions in the electrolyte and further metal electrowinning, but the rate of the spontaneous dissolution was low. Anodic dissolution of the alloy in the ammonia？ammonium sulfate solution led to the unfavorable distribution of metals among the slime, electrolyte and cathodic deposit.