银精炼技术的改进

采用传统的电解精练工艺,粗银所含杂质直接或间接地影响纯银产品的质量。作者提出了一种改进传统银电解工艺的方法—阴离子隔膜电解法,将银电解槽分为阳极区和阴极区,阻挡杂质元素从阳极区进入阴极区,使多杂粗银经1次电解得到纯度>99.99%的纯银产品。     

Freeze-Purification Process Upgrades Aluminum Purity

A process has been developed to produce specified-purity aluminum at a fraction of the cost of operating a three-layer electrolytic refining cell.     

Impurities and Nonmetallic Inclusions in Aluminum

A study of the effects of aluminum reduction cells, holding furnaces, and three-layer refining cells produced some interesting results.     

从废铂合金催化网中回收铂、钯、铑

硝酸工业产生的废铂合金催化网具有极高的经济价值。提出采用王水溶解-氯化铵沉淀分铂-氨水络合分钯-精炼工艺从废铂合金催化网中回收铂、钯和铑。结果表明,采用该工艺可获得纯度大于99.99%的海绵铂,纯度大于99.95%的海绵钯和铑粉;铂、钯、铑的直收率分别为98.6%、98.5%、97.1%。     

从钯银合金废料中回收钯的实验研究

以钯银合金废料为原料,采用硝酸溶解-盐酸沉银-二氯二氨络亚钯法提纯-水合肼还原工艺回收钯。结果表明,当浓盐酸用量为2 m L/200 m L混合酸液,反应时间1 h时,银沉淀率为99.98%;当氨络合和盐酸酸化沉淀过程溶液最佳p H分别为8和1.5,并经温水洗涤3次,二氯二氨络亚钯纯度达到99.99%以上;该工艺钯回收率大于90%,并制得纯度大于99.99%的海绵钯,其平均粒径不大于0.5μm。     

电解加钛铝合金的晶粒细化及其制备铝-硅合金的组织和性能

研究了电解加钛的晶粒细化作用,与AlTi和AlTiB细化剂对纯铝的晶粒细化效果进行了比较;对用电解低钛铝合金制备的A356合金和由纯铝制备并用AlTi或AlTiB细化处理的A356合金的组织与性能进行了对比研究;进行了利用工业铝电解槽生产的电解低钛铝合金熔体直接生产A356合金的工业试验。结果表明：电解加钛具有显著的晶粒细化作用,其细化能力与AlTiB的相当,明显优于AlTi中间合金的。在试验室条件下,用电解低钛铝合金制备的A356合金与纯铝制备并用中间合金细化处理的A356合金的拉伸性能相当;将电解低钛铝合金熔体直接用于铝．硅合金的生产是可行的,并具有节约能源,细化处理工艺简单,产品质量良好的特点。     

Performance comparison of AlTiC and AlTiB master alloys in grain refinement of commercial and high purity aluminum

1 Introduction Since AlTiC master alloys were improved greatly as a new type of master alloy used in grain refinement of aluminum and aluminum alloys in the middle of 1980s[1, 2], there were many important progresses in the preparation techniques and the …     

Optimal modifying and refining processes for A356 aluminium alloys

M illions of alum inium alloy com ponents are produced using A356 alum inium alloys, which provide high fluidity, good 'castability'and m echanical properties. A356 alloys are widely used to fabricate structural castings for autom otive and other industrial applications. For α (Al) refining,A356 alum inium alloys usually apply Al-Tim aster alloys in the range 0.08-0.20% Ti, resulting in high consum ption of Al-Ti m aster alloys and higher production cost.M odification ofthe Al-Sieutectic …     

Development of cube texture in multistage annealing of high purity aluminum foils

1　INTRODUCTIONThecubetextureisimportanttohighpurityalu minumfoilsforhighvoltagecapacitorsbecauseitcanenlargeeffectivesurfaceofaluminumfoilsandin creasecapacitancethroughchanneletching .Inordertoincreasethevolumefractionofthecubecompo nent ,a greatdealofresearchesontheformationmechanismofcubetexturehavebeendone ,andmanymethodswere proposed ,suchasimpuritycontrol ling[1,2 ] ,directionalsolidification[3] ,preheating[4 ] ,inhomogeneousrolling[5] ,vacuumannealing[6 ] andsoon .Inthispaperamulti…     

铸造铝合金精炼技术现状及发展

阐述了铸造铝合金的气孔形成机制、精炼理论及各种精炼技术的特点、研究现状和发展前景.旋转喷头吹气技术、FILD法、MINT法、FIP法和Heproject法等新型复合精炼技术的出现,极大地提高了铝合金熔体精炼水平.     

新型颗粒细化剂对A356铝合金铸态组织的细化效果

研究新型颗粒细化剂COVERAL MTS 1582对A356铝合金的细化效果.结果表明,经过COVERAL MTS 1582颗粒细化剂处理后,A356铝合金的铸态组织较添加传统细化剂Al-5Ti-B处理的二次枝晶间距(26.9μm)减小约23.8％.说明该新型颗粒细化剂对A356铝合金比Al-5Ti-B具有更显著的细化...     

氟盐法制备Al-Ti-B中间合金的研究

介绍了一种采用氟盐与铝液在高温下反应,制取Al5Ti1B中间合金细化剂的方法。从Ti、B的回收率、反应生成物以及微观组织的角度,对加料工艺、作用时间、搅拌强度等工艺因素做了分析。另外,对制取产品的细化效果进行研究。结果表明,在Ti加入量为0.05%~0.10%之间细化效果最好,该合金细化有效时间约为6 h。还在Al-Ti-B基础上引入稀土元素制取Al-Ti-B-RE中间合金细化剂,可进一步提高细化效果和长效性。     

Effect of aluminum on solubility and β phase stability of vanadium–hydrogen system

Effect of aluminum on hydrogen solubility and β phase stability of vanadium–hydrogen system have been investigated employing thermo gravimetric (TG), differential thermal analysis (DTA) and X-ray diffraction technique. Vanadium aluminum alloys have been prepared by aluminothermy process followed by electron beam refining and vacuum arc melting. High purity vanadium is used for the comparative study. The hydrogen solubility decreases with aluminum content and with temperature. Substantial variation of hydrogen desorption mechanism from α as well as from β phase was observed due to the aluminum content. Desorption kinetics and modification of phase stability are the two possible reasons for the observed phenomenon.     

分子识别技术分离提纯钯的工艺实验

采用分子识别材料SuperLig^ò2从含铂钯的溶液中选择性分离钯,钯吸附率大于99%,吸附、洗脱过程钯的直收率为95.87%,总收率为98.04%;得到的洗脱液氧化处理后生成钯沉淀,再经水合肼还原即可得到纯度为99.99%的钯粉。与传统的沉淀分离工艺相比,分子识别技术的生产流程短、铂不容易分散、操作方便、三废量少。     

ACID ELECTROLYTIC TREATMENT PROCESS OF SCRAP BATTERY SLUDGE

ＡＣＩＤＥＬＥＣＴＲＯＬＹＴＩＣＴＲＥＡＴＭＥＮＴＰＲＯＣＥＳＳＯＦＳＣＲＡＰＢＡＴＴＥＲＹＳＬＵＤＧＥ①ＣｈｅｎＷｅｉｐｉｎｇ，ＺｅｎｇＹｕｅ，ＹａｎｇＸｉａ，ＣｈｅｎＸｉｎｌａｎ，ＪｉｎｇＹａｎｂｏＩｎｓｔｉｔｕｔｅｏｆＥｎｖｉｒｏｎｍｅｎｔａｌ...     

Continuous dynamic recrystallization and discontinuous dynamic recrystallization in 99.99% polycrystalline aluminum during hot compression

The dynamic restoration behavior of 99.99% polycrystalline aluminum was investigated. The deformation was carried out by compression test at 533 - 773 K and initial strain rate of 0. 002 - 2 s^-1 to a true strain of 1.0 followed by water quench. Polarized optical microscopy and transmission electron microscopy were applied to observe the deformation microstructure. It‘s found that discontinuous dynamic recrystallization, which is commonly observed in lower stacking fault energy metals or ultra-high purity aluminum(≥99.999%), occurs when Zenner-Hollomon parameter(Z parameter) is low, but the true stress strain curve doesn‘t accompany stress oscillation.Continuous dynamic recrystallization occurs when Z parameter is intermediate, and only dynamic recovery takes place if Z parameter is high.     

Refining mechanism of salts containing Ti and B elements in purity aluminum

The effect of refiners containing Ti, B elements on the microstructure of purity aluminum has been studied in detail with optical microscopy, scanning electron microscopy (SEM) and energy dispersive analysis of X-ray (EDAX). It is shown that salts mixture containing 5Ti1B is the best refiner with the finest -Al grain and more than 10 h fading time. It is ascertained from the analysis of SEM–EDAX and thermodynamics analysis that the refining mechanism of salts mixture is mainly contributed to the heterogeneous nuclei of more fine TiAl₃ particles dispersed in the melting, which come from the reaction between the salts and aluminum. While (Al,Ti)B₂ has little or no refining effect, but it will reduce the size of TiAl₃ since the TiAl₃ nucleates and grows along the (Al,Ti)B₂ particle. That is to say, B atom has also refining effect on the purity aluminum when it is added simultaneously with Ti atom.     

功率超声对纯铝凝固组织的影响

对1.5 kg的纯铝熔体进行了功率超声辅助凝固试验,研究了功率超声对不同纯度纯铝凝固组织的影响,并比较了机械搅拌与功率超声的细化效果。结果表明,功率超声可以有效细化w(Al)=99.7%工业纯铝以及w(Al)=99.992%高纯铝的凝固组织。功率超声与机械搅拌相比,所获得的凝固组织更均匀且不易产生铸造缺陷。基于结晶游离理论讨论了功率超声的细化机制。功率超声的空化作用促进了超声耦合头附近液面的异质形核,声流作用则促进了晶粒的游离和沉淀。此二者的综合效应是等轴晶区形成的主要原因。     

Effects of electric field on recrystallization texture evolution in cold-rolled high-purity aluminum sheet during annealing

The effects of an external DC(direct current)electric field on recrystallization texture evolution in the cold-rolled aluminum sheets with 99.99%purity were investigated by means of X-ray diffraction techniques.The cold-rolled high-purity aluminum sheets were annealed for 60 min at 200,300 and 400℃,respectively with and without an external DC electric field of 800 V/mm.The results show that with DC electric field,the recrystallization cube texture is strengthened at the stage of grain growth. Possible reason for the strengthening of the recrystallization cube texture with the applied electric field may be attributed to both selected nucleation and selected growth of cube oriented crystal nuclei.     

高纯铝箔在异步轧制和再结晶过程中取向的演变

采用不同速比的异步轧制技术对99.99%的高纯铝板进行不同形变量的冷轧,并对冷轧样品进行不同温度和时间的再结晶退火.利用X射线衍射技术和TEM观测探讨了异步轧制条件下高纯铝箔中变形织构和再结晶织构的演变.结果表明:高速比的异步轧制(i=1.28)在样品中产生相对较强的旋转立方织构{001}(110).异步轧制后退火的高纯铝箔样品中,立方{001}(100)织构组分的再结晶晶核的形成和长大存在一个临界转变温度,此温度与异步轧制的速比成反比.异步轧制有利于降低高纯铝箔的再结晶温度,这与异步轧制提高高纯铝箔的形变储能有关.异步轧制有利于在低温时形成强的立方{001}(100)织构组分,但此时漫散较大;随着退火温度的升高,漫散范围明显缩至8°-10°.