稳定化退火工艺对铝镁钪合金力学和腐蚀性能的影响

采用半连续铸造.轧制技术制备了铝镁钪合金板材,研究了稳定化退火工艺对冷轧板材组织和性能的影响.结果表明,随稳定化退火温度的升高,板材强度下降而塑性升高,腐蚀抗力则先升而后降;随稳定化退火时间的延长,板材屈服强度有所降低而塑性变化不大,腐蚀抗力稍有增加.合金板材经300℃×lh稳定化退火可达到强度、塑性和耐蚀性的最佳配合.     

稳定化退火温度对Al-6Mg-0.3Mn-0.13Sc-0.13Zr合金板材组织和性能的影响

试验研究了不同稳定化退火温度对Al-6Mg-0. 3Mn-0. 13Sc-0. 13Zr合金冷轧板材组织和性能的影响。试验研究结果表明:随稳定化退火温度的升高,板材强度下降而塑性升高,腐蚀抗力则先升而后降;合金板材经350℃稳定化退火1h可达到强度、塑性和耐蚀性的最佳配合。     

冷变形工艺对铝-镁-钪合金性能的影响

采用半连续铸造方法制备了铝-镁-钪合金2.0 mm×1 200 mm×2 000 mm板材,研究了冷变形工艺对冷轧板组织和性能的影响。结果表明,铝-镁-钪合金随冷变形量增加强度升高,塑性下降。采用热轧后温轧或中间退火后冷轧,再在一定温度下进行稳定化退火的工艺,可以获得综合性能良好的铝-镁-钪合金冷轧板材。     

Sc含量对Al-Mg-Mn合金板材组织与性能的影响

采用半连续铸造-轧制技术制备了两种Sc质量分数含量为0.25%和0.10%的Al-Mg-Mn合金薄板,研究了稳定化退火工艺对两种不同Sc含量合金板材拉伸力学性能、剥落腐蚀性能和显微组织的影响。结果表明,两种合金冷轧板材稳定化退火过程中有相同的组织、性能变化规律,即随着退火温度升高,板材强度稍有下降而塑性升高,表现出很强的抗退火软化的能力,其中低Sc含量合金拉伸性能略低于高Sc含量合金的;其次,随退火温度的升高,板材抗剥落腐蚀的能力也表现出相同规律性的变化,200℃1 h左右退火时剥落腐蚀最严重,随着退火温度升高,抗腐蚀性能提高;两种合金冷轧板材在300℃1 h稳定化退火可以获得较好的综合拉伸力学性能和腐蚀性能,在此条件下,低Sc含量的合金板材抗拉强度、屈服强度和伸长率仍然分别达到437 N/mm2、340 N/mm2和16.3%,有很好的开发应用前景。     

稳定化退火对5B01合金性能和织构转变的影响

采用半连续铸造-轧制技术制备了5B01合金板材.研究了稳定化退火工艺对冷轧板材力学性能、抗剥落腐蚀性能以及织构的影响.结果表明,随稳定化退火温度的升高,5B01冷轧板强度呈现下降趋势而塑性升高,抗剥落腐蚀能力则先升后降.冷轧板材中主要存在黄铜织构{011}(211),铜织构{112}(111)和S织构{123}<634>,当退火温度升高到300℃左右时,板材的形变织构逐渐消失,分别向立方职构{001}(100)以及旋转立方织构{001}(110)转变.     

稳定化退火制度对Al-4.5Mg-0.7Mn-0.2Er合金板材组织和性能的影响

试验研究不同稳定化退火制度对Al-4.5Mg-0.7Mn-0.2Er合金冷轧板材组织和性能的影响。结果表明:冷轧板材在290℃退火,随着退火时间增加板材的强度逐渐降低、塑性逐渐增大;随着退火时间增加,板材的晶间腐蚀失重值逐渐减少;板材在290℃,保温45 min退火,其强度、塑性和耐蚀性为最佳。     

微量元素对Al-Mg合金组织和性能的影响

通过力学性能测试、显微组织观察,研究了微量元素添加对Al-Mg合金组织及性能的影响,并探讨其作用机制.在确定微量元素成分范围后,对冷轧板材的稳定化退火处理工艺进行了研究.试验结果表明,在300℃1 h稳定化处理,其力学性能最好,合金的抗拉强度达到420 N/mm2,屈服强度为308 N/mm2,伸长率为15%.     

退火工艺对7×××系某铝合金板材组织和性能的影响

为了改善7×××系某铝合金板材的塑性,试验研究了退火工艺参数对7×××系某铝合金冷轧板材组织和力学性能的影响。研究结果表明,7×××系某铝合金冷轧板材,开始再结晶温度为200℃,终了再结晶温度为360℃;最佳完全退火制度为退火温度380℃~390℃,保温1.0 h;可作为制定工业生产7×××系某。O状态某铝合金板材退火工艺制度的基础。     

轧制及热处理对医用Mg-2Zn-0.5Nd-0.5Zr合金板材力学性能和耐蚀性能的影响

用挤压轧制方法制备了厚度为1 mm的Mg-2Zn-0.5Nd-0.5Zr合金板材,并对板材进行后续退火和时效热处理,利用光学显微镜、扫描电镜、拉伸、电化学以及浸泡试验等研究了不同轧制温度和热处理对板材力学性能和耐蚀性能的影响.结果 表明:轧制温度从280℃升高到330℃,合金中的Nd元素析出量减少,第二相形貌改变,板材塑性和耐蚀性提高,伸长率由9.1％提高到15.2％,腐蚀速率由0.48 mm/y降低到0.28 mm/y.退火后板材伸长率和耐蚀性均进一步提高,其中330℃+T2处理的合金板材的综合性能最好,其抗拉强度和屈服强度分别为235 MPa和158 MPa,伸长率为24.3％,腐蚀速率为0.12 mm/y.时效处理后,合金的晶界处有大量的析出相析出,第二相强化效果显著,330℃+T6组的抗拉强度和屈服强度最高,分别为275.8 MPa和255.5 MPa,但板材伸长率仅为7.6％,腐蚀速率升高到0.43 mm/y.     

固溶处理对7B04铝合金冷轧板组织性能的影响

在实验室中制备了试验用7B04铝合金,经铸造-均质化退火-热轧-中间退火-冷轧后制得7B04铝合金板材,并对合金板材进行了后续固溶时效处理,研究了固溶处理对其组织和性能的影响。结果表明,470 ℃×1 h固溶+120 ℃×21 h时效处理铝合金冷轧板材再结晶明显,有少量晶粒处于伸长状态,除粗大第二相粒子外,未发现细小第二相粒子,综合力学性能较好,抗拉强度为596 MPa,屈服强度为537 MPa,伸长率为14.88%。固溶温度达到480 ℃时,合金再结晶明显,但保温时间不能超过0.5 h,否则合金强度和塑性下降。     

胫骨生物陶瓷复合材料的微结构增韧机理

扫描电镜观察显示胫骨是一种由羟基磷灰石和胶原蛋白组成的自然生物陶瓷复合材料.羟基磷灰石具有层状的微结构并且平行于骨的表面排列.观察也显示这些羟基磷灰石层又是由许多羟基磷灰石片所组成,这些羟基磷灰石片具有长而薄的形状,也以平行的方式整齐排列.基于在胫骨中观察到的羟基磷灰石片的微结构特征,通过微结构模型分析及实验,研究了羟基磷灰石片平行排列微结构的最大拔出能.结果表明,羟基磷灰石片长而薄的形状以及平行排列方式增加了其最大拔出能,进而提高了骨的断裂韧性.     

面向零件形状的计算机图形库的开发

论述了CAD技术中参数化设计的三种建模方法，重点介绍了基于特征的参数化建模原理。在此基础上，分析机械设计中的机构结构，归纳出其零件的几何特征构成。设计了机构CAD图形库，并提出了该图形库生成步骤和人机交互界面。     

FeCrAIW电弧喷涂层组织的致密化研究

采用激光辐照对FeCrAlW电弧喷涂层的组织进行致密化处理,借助扫描电镜和X衍射对涂层的组织进行了分析.测试了涂层的显微硬度.结果表明:涂层组织致密度提高,孔隙率明显降低.随着激光扫描速度的增加,涂层的显微硬度降低.在较低的扫描速度下,涂层与基体之间形成互熔区,涂层与基体之间产生良好的冶金结合.     

Prospects of the Use of Synergetic Approach to Solution of Problems of the Science of Nanomaterials

A synergetic approach to solution of problems of self-controlled synthesis of nanostructures and creation of self-organizing nanotechnologies is considered in connection with the superproblem of creation of materials with functional properties resembling those of biosystems. __________ Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 7, pp. 55 – 61, July, 2005.     

Kinetics of the oxidation of metals — Influence of self-diffusion of metal

The importance of the self-diffusion of a metal during its oxidation by a gas is treated for the cases of nonstoichiometric oxides having either interstitial cation or cation vacancies. We have established a general relationship for the reaction rate when a mixed diffusion process occurs. From this relationship, we have shown that the pressure dependence can be different, according to whether the rate-determining process is the self-diffusion through the metal or through the product.     

Features of formation of the structure in production of blanks of disks of heat-resistant nickel alloys

Conclusions To provide a high level of mechanical properties in wrought blanks of cast ÉP741NP and ÉP962 alloys it is necessary to form controlled structures. A necklace-type structure formed in homogenizing isostatic treatment, subsequent thermomechanical working including alternation of the operations of deformation in the (+)-area and recrystallization anneals, and final heat treatment is preferable. The temperature conditions of all stages of thermomechanical working are strictly controlled, especially the final operation of deformation and heating for hardening. To eliminate hardening cracks and distortions it is necessary to use molten salts at t=600°C as quenchants. The use of multiple production operations makes it possible to significantly reduce the structural inhomogeneity related to inhertance of the original dendritic structure. However, the structure of the final semifinished product is nevertheless characterized by a difference in occurrence of the processes of polygonization and recrystallization between the former dendritic cells and the interdendritic spaces in deformation and heat treatment.To obtain structurally homogeneous blanks for gas turbine engine parts it is necessary to use basically new methods of remelting such as vacuum double electrode remelting and electron beam remelting with an intermediate vessel.Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 12, pp. 25–29, December, 1991.     

Ab-initio calculation of enthalpies of formation of intermetallic compounds and enthalpies of mixing of solid solutions

A large number of ab-initio calculations of energies of formation of intermetallic compounds have been performed in the last 15 years. The currently used methods are listed. The paper presents a review of the aluminium based compounds which have been studied. Comparisons of calculated and experimental enthalpies of formation are provided for aluminim-3d and-4d transition metal alloys at equiatomic composition. The modelling of the enthalpies of mixing of solid solutions based on a given lattice is described.