Effect of chromium on the structure and mechanical properties of a tin bronze with 12% Sn

Conclusions With increasing chromium content in bronze Br012 from 0.03 to 0.7%, there is an increase in ductility with increasing temperature. The nature of the temperature dependence for ductility remains the same as for bronze without chromium.State Scientific-Research and Planning Institute for Alloys and Treatment of Nonferrous Metals. Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 11, pp. 45–48, November, 1981     

Evolution of the structure of tin bronze under dynamic channel-angular pressing

The study of the evolution of the structure of tin bronze under dynamic channel-angular pressing (DCAP) has been performed. For comparison, the evolution of the structure of commercial copper subjected to the same treatment has been investigated. A comparison of the microhardness of copper and bronze has been carried out after one and two DCAP passes     

土壤腐蚀过程中高锡青铜的形貌变化和元素迁移

采用在含模拟土壤介质(0.010 4 mol/L Na2SO4+0.028 2 mol/LNaCl+0.016 4 mol/L NaHCO3)的土壤中埋藏铸造青铜试样的方法研究高锡青铜的土壤腐蚀规律:采用金相显微镜观察腐蚀前后青铜的结构变化,扫描电镜(SEM)并结合能谱(EDS)对微区成分进行分析;用X射线荧光光谱(XRF)检测埋藏试样周围土壤中元素含量,同时用残留因子fCu/Sn和fCu/Pb定量分析腐蚀产物中Cu、Sn和Pb的残留情况.结果表明:在该环境下高锡青铜腐蚀首先从α相与δ相界面开始,且α相先于δ相发生腐蚀,留下未腐蚀的岛屿状δ相;高锡青铜腐蚀过程中Cu优先向周围土壤中迁移,最终形成的含O、C腐蚀产物中富含Sn和Pb.     

锡青铜堆焊接工艺

以斗轮产品中球铰座的锡青铜堆焊的实践为例,详细介绍了在ZG35SiMnMo母材上堆焊QSn6.5～0.1锡青铜的工艺过程,提出了采用大电流、高焊速的氩弧焊新工艺,解决了堆焊时易产生剥离、裂纹和气孔等工艺难点,有效地控制了堆焊质量,为今后推广铜合金堆焊工艺开辟了一个新领域,具有较广阔的应用前景.     

Corrosion behaviour of bronze in urban environments: influence of tin content

Abstract

In this paper, the influence of the tin content on the corrosion behaviour of copper alloys was investigated. Three different bicomponent bronze alloys were exposed to a natural urban environment. The kinetic corrosion processes and the patina properties were monitored using the open circuit potential, electrochemical impedance spectroscopy and spectrocolorimetry. Results show that the bronze corrosion behaviour improves upon increasing the tin content. In addition, the mechanism of the patina formation is different for the three alloys.     

形变热处理对铸造锡青铜组织与力学性能的影响

采用真空离心铸造方法制备了ZCu Sn10Zn2Fe Co锡青铜合金试样,通过对合金进行固溶处理、压缩变形以及随后的时效处理,研究形变及时效过程对合金显微组织及力学性能的影响规律。结果表明,形变热处理能够通过再结晶显著细化合金晶粒,晶粒大小由固溶态的20~40μm降低到几个微米,小部分晶粒发生了二次再结晶长大,XRD分析表明形变热处理后合金中并未产生新相;时效前的预冷变形能显著提高合金的力学性能,40%形变热处理后合金的布氏硬度由固溶态的92 HBW提高到146 HBW。     

退火对含铁钨青铜型铌酸盐结构和性能的影响

用固相烧结法制得了含铁钨青铜型铌酸盐Ba4Nd2Fe2Nb8O30陶瓷,研究了不同气氛下退火处理对其结构和性能的影响。退火前后的Ba4Nd2Fe2Nb8O30陶瓷均为单一的钨青铜相。退火没有改变其物相结构;但是退火通过调节氧空位的含量和离子有序程度明显影响到Ba4Nd2Fe2Nb8O30陶瓷的介电和铁电性能。在氮气和氧气中退火时,晶胞体积分别变小和变大。氮气下退火Ba4Nd2Fe2Nb8O30陶瓷介电常数和介电损耗均明显高于未退火和在氧气退火的样品。同时,氮气下退火的Ba4Nd2Fe2Nb8O30陶瓷无法测出室温电滞回线,而在氧气下退火样品铁电性较未退火时铁电性更明显。     

加热温度对锡青铜挤压成形后组织性能的影响

以锡青铜QSn7-0.2合金为研究对象,通过进行金相、硬度、拉伸、XRD、扫描电镜等实验方法来研究不同的加热温度对挤压成形后的锡青铜组织性能的影响。结果表明:加热至720℃挤压后坯料的组织性能最佳,尤其是断面收缩率,从而为下一步旋压工艺提供最佳的毛坯;并对加热至780℃挤压开裂的原因进行分析发现:加热至780℃时,坯料表面边部有锡汗冒出,随后挤压成形的杯形件端面在锡汗区域产生裂纹,对其组织进行分析发现,此区域显微组织呈铸态树枝晶,晶内偏析明显,并发现三元共晶组织(α+δ+Cu_3P),三元共晶体的存在引起合金的热脆,这是锡青铜杯形件热挤压时产生裂纹的主要原因。     

热处理温度对半固态挤压锡青铜组织性能的影响

以半固态挤压ZCuSn10P1锡青铜为研究对象,采用光学显微镜、扫描电镜、显微硬度仪、布氏硬度计、拉伸试验机研究了热处理温度对半固态挤压锡青铜微观组织和力学性能的影响规律。结果表明:热处理对半固态挤压锡青铜强度、硬度和组织影响较大。当热处理温度由250℃升高至650℃时,锡青铜抗拉强度先增加后降低,延伸率增加;布氏硬度先增加后降低;固相和固液界面显微硬度增加,液相显微硬度降低;固相平均晶粒尺寸增加,但热处理温度650℃时组织已不是球状而变成蔷薇状。随温度增加,固相中Sn和P元素增加,元素偏析减弱。综合性能较佳的热处理工艺为350℃保温120 min,此时锡青铜抗拉强度为402 MPa,延伸率为4.5%,布氏硬度为1360 MPa,与热处理前相比分别提高了3.88%,60.71%,6.25%。     

Effect of alloying elements on the structure and properties of iron with vermicular graphite

The effect of alloying elements (chromium, copper, and aluminum) on the processes of structure formation in cast iron with vermicular graphite is studied. The degree of graphitization of the iron is analyzed as a function of the kind and content of the alloying elements. The mechanical properties of irons alloyed with chromium, copper, and aluminum are determined. __________ Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 6, pp. 41–43, June, 2006.     

Effect of chromium content and heat treatment on creep of chromium bronze

Conclusions At testing temperatures below 0.5T_m the structure of the alloy affects the creep resistance in the same way as during tensile strength tests. The more dispersed (but less stable) structure ensures higher strength and a lower steady creep rate.At temperatures above 0.5T_m the less dispersed (but more stable) structure of the bronze is responsible for the lower creep rate.State Scientific-Research and Design Institute of Alloys and Treatment of Nonferrous Metals. Translated from Metallovedenie i Termicheskaya Obtabotka Metallov, No. 11, pp. 61–63, November, 1982.     

结构钢与锡青铜异种材料扩散焊

采用真空扩散焊的方法实现了30Cr3MoA结构钢与ZQSn10-2-3锡青铜的连接。测试了不同工艺下接头的抗拉强度,并通过扫描电子显微镜(SEM)和X射线能谱分析(EDS)观察了接头的微观组织成分。结果表明,在820 ℃时所得扩散焊接头质量最佳,该温度下提高压力和延长保温时间都能提高接头强度,820 ℃/1 h/10 MPa工艺下所得接头抗拉强度达294 MPa,拉伸试样均断于锡青铜母材,其焊缝为无缺陷的冶金结合,Cu元素和Fe元素互扩散层厚度约为3 μm。     

Effect of alloying element content on ion-nitriding behavior of Fe-Ti alloys

The ion-nitriding behavior of iron alloys with a titanium content of between 1.07 and 2.58 wt.% was investigated in the -phase region. The behavior was found to be analogous to the internal oxidation behavior of iron alloys: An internal-nitriding layer, where small TiN precipitates are dispersed, as well as a very thin surface layer of -Fe₄N were formed. A parabolic rate law holds for growth of the internal-nitriding layer. The kinetics of growth of the internalnitriding layer is discussed according to the rate equation of internal-oxidation, giving the diffusion coefficient of nitrogen, D _N ^app , in the layer. The measured D _N ^app decreases as the volume fraction of TiN, f, increases, indicating that the diffusion of nitrogen is apparently inhibited by the existence of TiN precipitates. Furthermore, the diffusion coefficient of nitrogen in -iron was evaluated by extrapolating D _N ^app to f=0, being in good agreement with that reported previously. The f-dependence of D _N ^app is discussed in terms of the effective area for diffusion of nitrogen in -iron.     

Induction centrifugal surfacing of the charge based on tin bronze powders with the addition of finely dispersed boehmite

The method of induction centrifugal surfacing of a charge based on tin bronze powders of medium dispersion with the addition of finely dispersed boehmite, which is an intermediate product in the production of the nanodispersed modification agent (α-Al₂O₃), is described. Its characteristic feature is that it can be produced in the surfacing conditions resulting in the chemical transformation of the intermediate product present in the charge to the nanodispersed modification agent followed by its uniform distribution in the liquid phase coating. The results of metallographic studies and tribotechnical tests of these coatings are presented. The experiments were carried out to determine the optimum (2–3%) boehmite content of the charge resulting in the highest parameters of antifriction and wear resistance properties of the coatings based on tin bronze after induction centrifugal surfacing.     

Effect of alloying additions on the structure and corrosion properties of zinc coatings

Conclusions Prolonged corrosion tests in a stream of sea water on samples galvanized in baths with different alloying additions showed that the corrosion resistance of zinc coatings in sea water can be improved by alloying with 0.01% Ti+0.05% Mg+0.1% Al and with 0.01% Ti.Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 5, pp. 45–47, May, 1974.     

铝镁合金化对VH2电子结构的影响

利用电荷自洽离散变分Xα方法计算Al、Mg合金化对VH2电子结构的影响.研究表明:在VH中加入金属Al以后,H原子的净电荷都减少,V原子的部分净电荷增加部分净电荷减少.v-H键间既有离子性相互作用,又有共价性相互作用;V-H键之间的相互作用减弱,氢容易被释放出来,从而改善了吸放氢性能;Al和Mg合金化以后,V和H原子的净电荷都减少,V-H键间的共价性相互作用增强;V-H键间的相互作用增加,有利于增加贮氢量,不利于改善吸放氢性能.