Amorphous-crystalline transition layers formation during quenching of Fe61Co7Zr10Mo5W2B15melt

New Fe-based multicomponent amorphous alloys have been developed recently based on empirical rules for large glass forming ability(GFA).In the present investigation,the master alloy ingot with the nominal composition of Fe61Co7Zr10Mo5W2B15(mole fraction,%)was prepared by arc-melting under Ti-gettered Ar atmosphere. The Fe-based uttons with different transverse cross sections were fabricated by arc-melting method,and the d2.5mm Fe-based rods were manufactured by injection technique.Characterization of the ingots and the parameters associated with the thermal stability were carried out by X-ray diffractometry(XRD)and high temperature differential scanning calorimeter(DSC),respectively.The interval of the supercooled liquid region is 39K for the Fe-based alloy.The GFA of Fe-based alloys is relatively lower,to the buttons obtained are all crystallized.The Fe-based rod exhibites a high Vickers hardness up to HV 1329.In addition,and amorphous-crystalline transition layers are observed in the rod.This transition zone is caused by unhomogeneous temperature distribution and relatively lower GFA for Fe-based alloys.     

开放式雾化器的雾化特性研究

讨论了在雾化压力、雾化器喷射顶角一定的条件下,中心孔直径的大小、气流的牵引等雾化参数对喷粉过程的影响。通过实验对开放式环孔雾化器在雾化过程中的堵塞现象进行了实验研究,解决了雾化器的堵塞问题。     

AC4B铝合金与H13金属型的传热系数计算

界面传热系数是铸造过程数值模拟的重要边界条件之一,但是其取值较难确定,而一般的计算方法又比较繁琐。为了解决这个问题,利用数值模拟软件求解界面传热系数。通过实测铸件凝固温度曲线,利用ProCAST中的反算模块计算得到了AC4B铝合金与H13金属型之间的界面传热系数。结果表明,界面传热系数应当设为温度的函数,且利用商业软件计算的结果能够满足工程需要。     

Microstructure characterization and mechanical properties of thermal sprayed Ni-20wt.%Al coating

Thermal sprayed Ni-20wt. % Al coating is fabricated on 6061-T6 aluminum alloy substrates by twin-wire arc spraying （TWAS）. Experimental results present that the average bonding strength is around 53 MPa and the average hardness reaches 325 HV. The Vickers microhardness of NiAl and Ni3Al intermetaUic compounds is larger than that of the substrate, which is beneficial for improving the wear property. Wear mechanism exhibits features of adhesive wear. Friction and wear test results indicate that the wet friction coefficient is higher than the coefficient of dry friction after 200 cycles, and variations of the wet friction coefficient are relatively smaller.     

喷射成形镍基高温合金的显微组织特征

采用喷射成形技术制备了镍基高温全金沉积坯,对合金沉积态、热等静压态和热处理态的显微组织进行了观察,并对共热处理后的维氏硬度、拉伸性能及断裂组织特征进行了测试和分析结果表明喷射成形高温合金组织细小、均匀,呈现出黄型的快速凝固组织特征。合金具有良好的高温组织稳定性。适宜的热等静压和热处理可使材料具有良好的拉伸性能     

快速凝固Al-Si合金干摩擦条件下的磨损特性

主要对挤压态和T6态RS/PM Al-Si合金的耐磨性进行了研究，并与传统耐磨合金ZL109进行对比。结果表明：两种状态RS/PM-Si合金的耐磨性比ZL109合金更为优越；相对于挤压态，经T6处理后RS/PM Al-Si合金的耐磨及减磨性有一定程度的改善。对磨损机制分析表明，RS/PM Al-Si合金的磨损主要以氧化磨损为主，而ZL109合金的磨损主要表现为粘着和塑性剥离磨损机制。     

微波加热法向沸石分子筛中引入金属离子—LA^3＋与NaX,NaY,N…

利用微波加热法研究了水溶液中稀土金属阳离子Ｌａ＾３＋与沸石分子筛ＮａＸ，ＮａＹ，ＮａＬ，ＮａＭ之间的离子交换反应体系，考察了溶液浓度，加热时间，功率等因素对交换度的影响并运用正交试验做了直观分析优化，通过对比实验及ＸＲＤ结果表明，在相同的工艺条件下，微波加势法比传统加热快几十倍，且分子筛晶相结构没有变化。     

超音速气雾化高硅铝合金粉末高温加热组织及性能演变

本文利用超音速气体雾化法制备快速凝固高硅铝合金粉末，对合金粉末在不同温度加热处理后合金相组合，显微组织及显微硬度的变化特征进行系统研究。结果表明合金粉末在加热过程中，随着加热温度的升高，其组织中非平衡相逐渐转变为平衡相，同时有新的第二相沉淀析出，合金组织第二相在高温加热过程中有粗化趋势，合金显微硬度在低温加热时有下降趋势,随后升高温度不再下降，而是维持在相对稳定的水平。     

国内首座自锚式柔性悬索桥--广西桂林丽君桥主缆、吊杆安装施工技术

介绍国内首座自锚式柔性悬索桥的设计、施工计算以及主桥上部结构的主缆、吊杆安装工艺。     

恶性肿瘤局部热疗用纳米磁性材料

简要回顾了基于磁性材料热疗的发展过程，介绍了恶性肿瘤局部热疗用纳米磁性材料目前的主要研究发展现状，并探讨了未来发展的方向，以及可能需要解决的一些问题。