含钴铜转炉渣的工艺矿物学

研究了铜转炉渣的化学与矿物学特征,用光学显微镜查明了炉渣各主要渣相为铁橄榄石,磁铁矿和无定形玻璃体,铜主要以冰铜相裹夹于渣相中,铜滴的尺度与渣的冷却历史有关。用X射线衍射谱,扫描电子显微镜,X射线能谱和X射线波谱及化学物相分析,对铜和钴的赋存状态及在各相中的分布进行了表征和量化。结果表明,钴主要以类质同象形式取代铁橄榄石和磁铁矿晶格中部分Fe^2 ,作为氧化物富集其中,二者约占钴总量的95％,渣中钴的提取需要以铁橄榄石和磁铁矿的分解为前提,使钴的氧化的游离出来而酸溶。     

Nonclassical constitutive model involving void evolution of casting magnesium alloy

The void evolution equation and the elastoplastic constitutive model of casting magnesium alloy were investigated. The void evolution equation consists of the void growth and the void nucleation equations. The void growth equation was obtained based on the continuous supposition of the material matrix, and the void nucleation equation was derived by assuming that the void nucleation follows a normal distribution. A softening function related to the void evolution was given. After the softening function was embedded to a nonclassical elastoplastic constitutive equation, a constitutive model involving void evolution was obtained. The numerical algorithm and the finite element procedure related to the constitutive model were developed and applied to the analysis of the distributions of the stress and the porosity of the notched cylindrical specimens of casting magnesium alloy ZL305. The computed results show satisfactory agreement with the experimental data.     

钢锭内部孔隙性缺陷锻合过程的数值模拟

通过比较圆柱体试样内部孔洞锻合过程的模拟计算结果和实验结果,确立了钢锭内部孔隙性缺陷锻合过程的模拟法,并对长孔型缺陷和短孔型缺陷的锻合过程进行了计算,得到各类孔洞的闭合规律,且定量给出了不同位置处孔洞闭合时所需的临界压下率。从孔洞闭合的力学本质角度,对钢锭内部的等效应变分布情况进行了研究。结果表明,孔洞的闭合完全是由于应力集中并达到一定程度的变形所引起的。其中,四面体孔最难闭合,为所有孔洞锻合所需临界压下率的上限值。锻合区域的给出,为制订锻造工艺提供了理论依据。     

The deposition and recrystallization textures of copper electrodeposits obtained from a copper cyanide bath

The textures of copper electrodeposits obtained from an alkaline copper cyanide bath changed from <110> to <111> with increasing cathode current density and with decreasing bath temperature. The <111> and <110> textures of copper electrodeposits changed to the <100> and textures, respectively, when they were recrystallized. These results are similar to those in copper electrodeposits obtained from acid copper sulfate and acid copper fluoborate baths.     

含铜污泥还原熔炼过程金银捕集分布规律研究

含铜污泥还原熔炼过程产出金属铜相(Cu)和锍相(冰铜,mt),铜、镍、金和银在两相中均有分布,统计了约100批次熔炼产品,分析其分布规律。结果表明,金、银在铜相中的分布系数(βAu Cu、βAg Cu)与铜在铜相中的分布系数βCu Cu呈正相关,说明铜相对金、银的捕集能力比锍强,且对金的捕集能力强于银;银分配系数LAg与铜、镍在铜相中的分布系数(βCu Cu、βNi Cu)呈正相关,金、银分配系数(LAu、LAg)与锍相中镍含量([Ni]mt)均呈弱负相关,说明锍相对银的捕集能力强于金。     

Chemical and mineralogical characterizations of a copper converter slag

A copper converter slag was examined chemically and mineralogically to determine its existing phases,in particular those containing Co and Cu.The slag consists predominantly of fayalite and magnetite,together with some glass,chalcocite,and metallic copper,Copper is entrapped in the slag mostly as chalcocite and metallic copper,as well as trace copper oxide,There was no indication of any independent Co was detected in all the phases of the slag by SEM-EDX(scanning electron microscopy equipped with model EDAX-9100 energy dispersive spectrometer)and WDS(model WDX-2AX-ray wave-length dispersive spectrometer.).     

退火处理对铜导线晶界特征分布及导电性能的影响

对拉拔法制备的工业纯铜导线进行不同参数下的退火处理,并采用电子背散射衍射(EBSD)技术对退火前后样品的晶界特征分布(GBCD)进行了测试。结果表明:退火处理后,铜导线导电率和特殊晶界比例均有一定的提高,导电率随Σ3晶界比例增大而提高,而晶粒尺寸对导电率没有明显的影响。550 ℃退火15 min时,特殊晶界比例达到最高值57.59%,Σ3晶界比例达到最高值49.80%,导电率可达59.29%IACS,是退火前的2.56倍。     

金属铜电沉积过程中分形研究

以环形金属铜片作为阳极，细铜丝作为阴极，研究了酸性电解液条件下金属铜电沉积过程中的二级枝晶生长现象，测定了沉积时间－电流关系曲线，对外加电压，电解液中硫酸铜浓度等对金属铜的电沉积产物形貌及其分维数的影响进行了观测，分析。研究发现，沉积过程中，电流随沉积时间的增加而变大，沉积产物的分维数随电解液中硫酸铜的增加而变大，随外加电压的变动而波动。     

基于修正的Gurson模型预报大锻件内部空洞型缺陷的演化

Gurson模型要求材料的静水应力或等效应变无穷大时才能实现材料内部的空洞闭合,而这一条件并不符合实际情况。文章对Gurson模型中的各参数进行了试验设计,通过开发子程序,对不同试验参数下的空洞体积变化过程进行了模拟仿真,据此获得了修正的Gurson模型参数,从而将其应用于大锻件锻造过程的空洞体积变化模拟中。结果表明,修正后的Gurson模型给出的空洞体积变化率,与直接设置空洞的有限元模拟结果很接近,从而大大改善了空洞闭合的预报结果。     

FCC晶体中晶体取向对孔洞长大和聚合的影响

通过编制率相关有限元用户子程序，采用包含一个和两个球形孔洞的单胞探求了FCC晶体中晶体取向对孔洞长大和聚合的影响。计算结果表明：晶体取向对孔洞长大的影响较大，孔洞的形状和长大方向与晶体取向密切相关：由于变形不均匀，孔洞在晶界处产生尖角，易形成裂纹。由于约束较少，孔洞周围和两孔洞间的区域塑性变形较大，晶体的转动和滑移主要集中在孔洞周围以及两孔洞间的区域。     

日本关于固相扩散焊界面空洞收缩机理的研究

日本学者对固态扩散焊界面空洞收缩机理进行了系列研究：（1）提出了二维界面几何模型;指出界面空洞收缩是在塑性变形、粘塑性变形、界面扩散及体积扩散四大机制作用下实现的：并估算了各机制的作用大小,（2）在基于空位扩散的界面扩散的数值计算中,考虑了因界面扩散引起的刚性位移及在不同接合率下的空沿间隔2L的变化;另外还研究了空洞表面扩散快慢对界面扩散的影响。（3）首次提出了粘塑性变形机制的有限元模型,并发现在扩散焊后期拘束对空洞收缩速度有显著的抑制作用。     

薄壁铜管弯曲成形仿真研究

利用有限元仿真技术研究了半圆、椭圆及关节3种芯杆结构对薄壁铜管弯曲成形质量的影响,基于上述3种芯杆结构,采用ABAQUS显示算法对U管成形过程进行数值模拟,并加以试验验证。结果表明:半圆芯杆可有效降低管材的壁厚减薄率,椭圆芯杆有助于改善铜管弯曲处的截面形状,关节芯杆综合了两者的优势,且伸出范围为1.5~2 mm。     

基于Boost变换器的ZVT软开关三相APFC仿真研究

随着对电网电能质量的要求日益严格,提高输入功率因数、减少谐波电流污染已成为逆变式开关电源的重要性能指标。首先从理论上分析了将单相有源功率因数校正(APFC)技术应用于逆变式等离子弧切割电源三相整流、电容滤波电路的可行性和优势;然后针对APFC电路的功率器件开关损耗,研究了零压过渡(ZVT)软开关APFC电路的负载适应性。对基于升压变换器(Boost Converter)的ZVT软开关三相APFC电路的应用环境和工作模态进行了详细分析,指出采用非连续导通模式的合理性。采用PSpice软件对APFC电路进行了仿真研究,给出了不同输出功率下的电源输入和功率器件的电压电流仿真波形。研究结果表明,采用非连续导通模式的APFC电路可实现全负载范围的功率器件ZVT软开关,电源系统的输入功率因数可提高至0.94以上,有效改善了输入电流波形,谐波电流污染大幅降低。     

Relationship between solid fraction and distribution of Pb in Al-Pb ingot

ＩＮＴＲＯＤＵＣＴＩＯＮＡｌ Ｐｂｈｙｐｅｒｍｏｎｏｔｅｃｔｉｃａｌｌｏｙｉｓａｎｅｗｔｙｐｅｂｅａｒ ｉｎｇｍａｔｅｒｉａｌ[1] .Ｇｒｅａｔｅｍｐｈａｓｉｓｈａｓｂｅｅｎｐｕｔｏｎｉｔｅｓ ｐｅｃｉａｌｌｙｓｉｎｃｅ 1990ｓ[2～ 4 ] .ＰｂｈａｓｅｘｃｅｌｌｅｎｔｌｕｂｒｉｃａｔｉｎｇｐｒｏｐｅｒｔｙｗｈｉｃｈｃａｎｍａｔｃｈｔｈａｔｏｆＳｎ ,ｂｕｔｉｔｓｃｏｓｔｉｓｍｕｃｈｌｏｗｅｒｔｈａｎｔｈａｔｏｆＳｎ ,ｓｏＡｌ ＳｎａｌｌｏｙｉｓｒｅｐｌａｃｅｄｂｙＡｌ Ｐｂａｌｌｏｙｉｎｔｈｅｆｉｅｌｄｏ…     

焊药混合时间对铜及铜合金手工自蔓延焊接的影响

铜及铜合金手工自蔓延焊接是一种融合自蔓延焊接和手工弧焊等技术的新型应急焊接技术.手工自蔓延焊接的质量控制和焊接接头性能会受到燃烧型焊条成形工艺参数的影响,而焊药混合时间又是焊条成形工艺参数中重要的因素.通过试验研究了颗粒团聚与混料时间的关系,不同混料时间下粉末颗粒分布情况,焊条燃烧速度与混料时间的关系曲线,并且通过金相...     

Simulation on temperature field of TIG welding of copper without preheating

1 Introduction Fusion welding of red copper easily leads to many defects, such as backing’s lack of fusion, groove’s hard of through-welding, bad surface forming. All these have relations with thermophysical performances of red copper. The heat conduct…     

镦粗过程中摩擦对空洞演变行为的影响

采用有限元模拟方法,模拟计算了摩擦因子为0. 3,0. 5和0. 7时,锻件不同位置空洞的闭合情况。分析了不同摩擦因子下,锻件不同位置的空洞高度的变化规律,结果发现:锻件内部空洞比边缘的空洞更容易闭合,并且随着摩擦因子的增大,内部空洞闭合速度加快,边缘空洞闭合速度减慢。分析摩擦因子、静水应力、等效应变、空洞闭合速度的关系发现:在锻件的内部位置,随摩擦因子增大,静水应力绝对值增大、等效应变增大、空洞闭合速度增大;在锻件的边缘位置,随着摩擦因子增大,等效应变减小、空洞闭合速度减小。摩擦因子对锻件边缘位置空洞闭合情况和等效应变的影响大于对锻件内部位置空洞的影响。     

铜及铜合金焊接研究现状和手工自蔓延焊接铜问题探讨

概述了铜及铜合金的气焊、钎焊、活性焊、MIG焊、搅拌摩擦焊及热摩擦搅拌焊、激光焊、电子束焊等常规焊法和自蔓延焊法的技术特点及国内外的研究现状.论述了在当前铜及铜合金手工自蔓延焊接技术的研究过程中如何借鉴融合其他焊接技术的工艺及机理,并讨论了铜及铜合金手工自蔓延焊接所存在的问题并对其产生原因作了初步分析.着重分析了焊接时...     

Release and chemical speciation of copper from anti‐fouling paints with different active copper compounds in artificial seawater

Release rates of total copper in artificial seawater (without organic matter) from anti‐fouling paints of different active copper compounds range from 0.5 to 75 μg cm^?2 day^?1. Approximately 80% of the released total copper was determined to be electrochemically active (labile fraction) for all paints investigated. The remaining fraction is more strongly bonded non‐bioavailable copper complexes with species released from the paints. Model calculations, using MinteqA2, predicted only a small portion (≈ 6%) of the total copper released as free cupric ions (Cu(H₂O)²⁺₆), the most bioavailable form of copper. Similar results were obtained with bioassay testing using bacteria and yeast on released copper from massive copper sheet exposed at identical conditions. The large difference between the total and the bioavailable copper fraction emphasizes the importance of generating chemical speciation data for accurate decisions of potential adverse effects of copper release from anti‐fouling paints. The observed release of other metals and organic substances from the paint matrix, implies the importance to assess an integrated response from released species from paints of anti‐fouling, and not only from single ingredients.