Application of electromagnetic-assisted stamping (EMAS) technique in incremental sheet metal forming

The application of high velocity electromagnetic-assisted stamping (EMAS) technique in incremental sheet metal forming has been proposed. EMAS whose principle is based on Lorenz force is a hybrid forming process that uses both quasi-static conventional stamping technique and electromagnetic forming actuators built into sharp corners and other difficult-to-form contours to form metals. The recent push to use more artificial intelligent (AI) aluminum alloys in automobile and aircraft industries as a result of increasing demand for fuel efficient cars and aircrafts, large size vehicle panels, improved formability limit of materials and weight reduction have placed EMAS as one of the best high velocity forming technique.It is believed that the end result of this vision will lead to more cost effective land and aerospace vehicles.     

稀土对复合处理渗层热疲劳性能的影响

进行了稀土对４Ｃｒ５ＭｏＳｉＶｌ钢硫氮碳共渗加氧化复合处理渗层热疲劳性能影响的研究结果表明，添加稀土的渗层比未添加稀土的热疲劳性能有显著提高。     

阿塞尔轧管机组轧制规格范围的确定

总结了引进的阿塞尔轧管机热负荷试车及试生产情况。通过不同径壁比荒管的轧制，实现了扩径减壁、等径减壁和减径减壁三种轧制形式，从而确定了阿塞尔轧管机组的轧制规格范围。     

L12型Al3Sc基金属间化合物有序化行为和力学性能的第一性原理计算

本文采用亚晶格模型,辅助以第一性原理总能计算,研究了L1₂型Al₃Sc基金属间化合物中元素的占位有序化行为和力学性能。结果表明：Al₃Sc合金呈现完全有序化,其中Al占据3c亚晶格位置,Sc占据1a亚晶格位置；L1₂-Al₃(Sc_0.75M_0.25)金属间化合物(M=Y、Ti、Zr和Hf)也呈现完全有序化,第三组元M均只占据1a亚晶格位置,这些元素的占位行为均不受温度的影响。L1₂-Al₃(Sc_0.75M_0.25)金属间化合物均满足力学稳定性条件。M为Y时,L1₂-Al₃(Sc_0.75M_0.25)金属间化合物的剪切模量、体弹模量和杨氏模量和硬度下降；M为Ti、Zr或Hf时,随着原子半径增大,剪切模量、体弹模量、杨氏模量和硬度逐渐降低,其中Ti的加入可使L1₂-Al₃(Sc_0.75M_0.25)金属间化合物的塑性和韧性达到最好。     

NACE国际标准推荐做法液态环氧树脂管道外涂层（25O～76Oμm）针孔检测

本标准给出了目前阶段管道现场安装前对液态环氧树脂（FBE）涂层的针孔进行检测的推荐技术。并且给出了不同涂层厚度的推荐检测电压。     

熔体的定向受迫流动对高纯A1柱状晶生长特征的影响

研究了在离心力场和电磁场作用下融熔高纯Ａ１的凝固现象。研究结果表明，在二种力场共同作用下，产生的熔体定向受迫流动对柱状晶的生长方向和形态有很大影响，柱壮晶朝向迎流一侧发生倾斜，并随着离心转达和磁场强度的增加，柱状晶细化，倾斜角度增加。首次利用柱状晶间层流边界层理论解释了这一现象。     

基于ANFIS的桥式起重机焊接箱形梁疲劳裂纹扩展预测

疲劳裂纹扩展问题是桥式起重机主梁结构设计的一个重要问题.为了确保起重机的安全,需要提前预知桥式起重机焊接箱形主梁的疲劳裂纹扩展长度,因而要建立一个精准的预测系统对裂纹长度进行预测.为此建立一个基于自适应模糊推理系统(ANFIS)模型对桥式起重机焊接箱形主梁疲劳裂纹扩展长度进行预测.该模型通过一套If-Then的规则,自动调整出适当的隶属函数以满足所要求的模糊推理的输入和输出关系;只要选取适当的模糊规则数,就可以得到最接近实际裂纹扩展长度的预测结果.根据桥式起重机焊接箱形主梁疲劳试验结果,并与三层神经网络模拟结果和三次样条函数模拟结果进行比较,可以看出利用ANFIS系统建立的预测疲劳裂纹扩展的模型可以有效控制误差范围,所以能够准确的预测出疲劳裂纹的扩展情况.     

压铸脱模剂喷涂时热交换特点的基础研究

针对压铸生产过程中模具表面脱模剂喷涂时的热交换特点以及喷涂时的热物理特性进行了研究,讨论了脱模剂喷涂技术的改进.结果表明,喷涂时的传热特性接近于沸腾换热,模具的表面粗糙程度对于该过程的换热没有影响而对水质的影响很大;新的脱模剂脉冲喷涂技术可以大幅提高模具寿命,同时节省脱模剂用量,提高铸件表面质量,并且不降低压铸生产效率.     

超细WC粉末的强化球磨和表面钝化

研究了超细WC球磨破碎和分散机理,通过表面活性剂和聚合物的添加,降低了超细WC的球磨料浆粘度,提高了WC的球磨效率;经过150小时球磨后WC的BET小于100nm,X衍射晶粒度小于30nm。WC表面聚合物包覆的物理改性,其抗氧化能力提高了一倍。     

Energy transfer and frequency upconversion in Yb, Er co-doped sodium–lead–germanate glasses

Yb³⁺–Er³⁺ co-doped Na₂O–GeO₂–PbO glass suitable for developing optical fiber lasers and amplifiers has been fabricated. The energy transfer efficiency from Yb³⁺ to Er³⁺ was investigated in the glasses with different Yb³⁺–Er³⁺ concentration ratios and the maximum energy transfer efficiency was found to be 67% at the Yb³⁺–Er³⁺ concentration ratio of 5:1. Subsequently, the studies of upconversion emissions in the visible range were performed. An intense green together with a relatively weak red emission was observed under the excitation of 976 nm diode laser. The quadratic dependence of the green emission on excitation power indicates that a two-photon absorption process occurs under a 976 nm excitation. However, for the red emission the slope of log-log plot of integrated intensity versus pump power declines with increasing Yb³⁺ ions content, indicating it is not resulted from a biphotonic process.