Crystallization and microstructure evolution of amorphous Al85Y4Nd4Ni7 alloy

The mixture model of Al85Y4Nd4Ni7 alloy in which a partially crystallized amorphous alloy is regarded as a nanocomposite of an Al nanoparticle and a remaining amorphous matrix is presented. Its evolution in the process of crystallization has been investigated by differential scanning calorimetry (DSC), X-ray diffraction (XRD), and transmission electron microscopy (TEM). Mainly amorphous structure with α-Al nanocrystals embedded in the amorphous matrix has been revealed by melt spining the alloy. Crystallization is showed to occur in three stages: (I) crystallization of amorphous alloy and formation of A1NiY, A1NdNi and unknown crystalline phases, (2) formation of Al3Y and Al3Nd, and (3) formation of Al3Ni.     

Numerical simulation on magnetic flux leakage evaluation at high speed

High-speed non-destructive inspection (NDI) systems using magnetic flux leakage method (MFL) is in great demand in online metal inspection and defect characterisation, especially in pipeline and rail track inspection. For MFL systems at high speed measurement, in addition to magnetic flux, eddy currents exist in metal specimen because of the relative movement between the probe and specimen. These currents alter the profile of electromagnetic field, which increases difficulty in signal interpretation and defect characterization. In this paper, eddy currents generated by high speed movement and their characterisation in high-speed MFL inspection systems were investigated by using numerical simulations. Besides, the MFL signals from high speed MFL measurement against defect depth were examined.     

断路器机械特性及参数检测装置

论文介绍了所研制的断路器三相同步性检测装置,以国产DBA、DBG、DBB等九种断路器为研究对象,选用工控机、伺服电机、力传感器和高速数据采集卡设计了一套数据采集、处理系统,完成对其分合闸机械特性参数、力变化曲线和过程曲线的自动测量、显示、存储查询及打印,检测功能全、速度快、精度高,可以将断路器诸多机械特性的测量集于一体,大大简化了测量过程,节省人力物力.最后对其测量结果及适用性作了分析和评议.     

TIG熔敷堆焊快速成形视觉传感系统的研究

对于TIG熔敷堆焊快速成形视觉传感系统进行了一定的研究；通过对TIG熔敷堆焊快速成形的原理的分析．介绍了选择CCD作为TIG熔敷堆焊快速成形视觉传感器的动能；从光学理论得出视觉系统的标定方法；从实验结果来看视觉传感系统所得到的图像能够清晰反映出TIG熔敷堆焊的焊接轨迹。     

Cup-drawing formation of steel sheet with nickel coating by finite element method

The finite element method （FEM） simulation of deep-drawing of steel sheet with nickel coating based on the solid element and dynamic explicit method was reported. Penalty function method was used to treat the contact algorithm. The friction between the punch and coating sheet was based on a Coulomb formulation. The combination of coating and substrate was defined as tied with failure contact. The results of the simulation illustrate that the steel sheet and the nickel coating do not delaminate at the interface. The stress field of the nickel coating is more complicated thala that of the steel substrate. Furthermore, it is found that the punch-nose radius is the most unsubstantial part for the intensity of the entire deep-drawing part and the thinnest part, it is a dangerous zone for the break. At this zone, the thickness thinning of the steel sheet and the nickel coating are up to 4.8% and 6.7%, respectively. Meanwhile, it is found that the curve of the variable blankholder force （VBHF） designed can improve the formability of sheet.     

科技创新促进国产药芯焊丝快速发展

技术创新能力是国寐和企业竞争力的关键因素，天津市金桥焊材集团有限公司在药芯焊丝发展项目中始终坚持科技创新的精神，使国产药芯焊丝实现了跨越性发展。本文介绍了金桥药芯焊丝的发展历程和药芯焊丝制造过程中的关键技术。     

台式快速成型设备扫描系统研制

介绍了在台式快速成型制造系统研制中，为稳定系统性能、降低设备造价所采取的技术措施：通过对扫描方式的比较，选择了X－Y二维导轨式扫描方式；用普通紫外灯光源取代激光光源；基于锥度光纤传输、聚焦的光路系统等技术。     

镁合金的活性电弧焊接

在不同的电流条件下,研究了9种常见氧化物、氟化物、氯化物活性剂在镁合金交流氩弧焊及变极性等离子焊弧中的行为.结果表明:活性剂TiO2、Cr2O3、AlF3、NiCl2、CdCl2、ZnCl2、MgCl2使镁合金交流氩弧焊焊缝熔深增加;MgF2、SiO2使镁合金交流氩弧焊焊缝熔深减小;TiO2、SiO2、Cr2O3、AlF3、NiCl2、CdCl2使镁合金变极性等离子弧焊焊缝熔深增加;MgF2、ZnCl2、MgCl2使镁合金变极性等离子弧焊焊缝熔深减小;活性剂对镁合金交流氩弧焊焊缝熔深增加的作用大于对镁合金变极性等离子弧焊的;电弧收缩是活性剂使得镁合金电弧焊焊缝熔深增加的原因之一;活性剂的加入使得焊缝的晶粒比未涂敷活性剂时粗大.     

半固态Y112铝合金成形组织与性能

采用近液相线半连续多模铸造法制备出Y112铝合金半固态坯料。分别考察了半固态合金流变成形件、触变成形件和常规压铸件的组织与性能。结果表明：Y112铝合金的半固态流变成形件的组织细小、均匀，硬度为112HV，优于触变成形件和常规压铸件的。     

Z512钻床数控化改造

针对企业电路板等板件钻削加工特点,结合Z512钻床现有条件,确定了钻床的数控化改造方案,介绍了机械部分的改造设计、控制系统的硬件设计和软件设计.改造后的钻床提高了加工效率和加工精度,取得了较好的应用效果.