A study on the characteristics of electrical discharge textured skin pass mill work roll

Electrical discharge texturing induces a recast white layer on the skin pass mill work roll surface, which forms the surface topography required for outer autobody steel strips and a heat-affected zone beneath it. The characteristics of these thermally influenced layers were studied by means of optical and scanning electron microscopes, X-ray diffractometer, radio frequency-glow discharge optical emission spectrometer and microhardness tester. It was found that the electrical discharge texturing led to a dramatic hardness drop in the white layer, which was attributed to the high amount of retained austenite. Moreover, softening was observed in over tempered section within heat-affected zone. Sub-zero and cryogenic treatments seem to be potential methods in order to restore the hardness of white layer and over tempered zone with an increase in both. Additionally, de-ionised water was found to be a promising dielectric liquid to abstain from retained austenite.     

增加变形产量的措施

为改善纱线质量，满足进一步提高产量的要求，可使用短的高温加热器和强制冷却履带，使变形区长度缩短一半，同时生产速度可提高40％－50％。     

变形工艺对锦纶6高弹丝染色性能的影响与控制

讨论了锦纶６ＤＴＹ变形加工中，加工速度、牵伸比、定型温度、速比、含油率等工艺参数对纤维染色均匀性的影响，并提出了一些控制措施。     

Optimising the design of textured surfaces for reducing lubricated friction coefficient

Under operating conditions which are unfavourable for lubrication, such as high load and low velocity, the use of textured surfaces significantly promotes the formation of a thick lubricant film and an improvement of the friction coefficient. This paper relates to the manufacture of textures using a photolithography and chemical etching process. Different surface geometries, texturing densities and depths were designed to analyse the influence of these parameters. The friction coefficient was measured in a ball‐on‐disc tribometer under different lubrication regimes, and the results have been used to develop an artificial neural network with texturing optimisation potential. © 2016 The Authors Lubrication Science published by John Wiley & Sons Ltd.     

ZCuSn10Zn2铜合金激光表面微造型工艺试验

为加工出符合摩擦学性能要求的ZCu Sn10Zn2铜合金表面微造型形貌,采用激光微造型技术对ZCu Sn10Zn2铜合金表面进行网格图案化处理,利用共聚焦显微镜和X射线应力测定仪对加工后的试样进行表面形貌表征及残余应力测试。考察不同工艺参数对材料耐磨损性能的影响。结果表明:激光微造型后材料的表面粗糙度随激光功率的增大先减小后增大,微沟槽的深度随激光功率的增大先增大后减小,微沟槽的宽度与工作电流成正相关性,但随电流的增大趋于饱和。表面残余应力随工作电流增大趋势明显,微造型后,表层存在较大的残余拉应力。试验结果对深入探索ZCu Sn10Zn2铜合金的激光微造型工艺提供了一定的数据基础。     

激光复合织构焊管轧辊模具成形有限元模拟与试验研究

目的提高焊管成形质量,为激光复合织构轧辊模具产业化提供试验依据。方法通过数值模拟方法模拟焊管轧辊成形过程,获得不同摩擦系数组合下板料成形应力应变和径向厚度数据,并获得最优模具表面织构方案,为轧辊模具表面织构处理提供依据。依据数值模拟结果,运用激光表面织构技术对辊子模具表面进行复合织构加工处理,开展激光复合织构模具和未织构模具成形对比,并对成形件进行残余应力、应变、边缘减薄率等检测分析。结果数值模拟结果表明,下辊边缘区域应为减摩区,上辊边缘区域应为增摩区;应对下辊边缘区域进行激光微织构减摩,上辊边缘区域进行激光毛化增摩。成形试验结果表明,试验结果与数值模拟结果基本一致;与未织构模具相比,激光复合织构焊管轧辊模具优化了成形件的应力应变分布,降低了板厚边缘减薄率(5.06%),提高了成形件的均匀性(3.9%),成形件边缘区域形成了残余压应力。结论激光复合织构焊管轧辊模具相比未织构模具,可显著改善成形件的边缘稳定度和成形质量。     

多晶Si太阳电池新型制绒工艺研究

提出一种采用二次酸腐蚀的多晶Si制绒新方法,首先在HF/HNO3的富HNO3体系中对Si片进行一次腐蚀,之后在富HF体系中进行二次腐蚀,以优化表面织构,减少光在Si表面的反射损失。制绒后,用扫描电子显微镜(SEM)对Si片进行了表面形貌分析,用Carry 5000紫外-可见-近红外分光光度计测量反射谱线,得到未镀减反射膜(ARC)的二次腐蚀制绒的最低反射率为20.34%,比一次腐蚀制绒(22.70%)低2.36%。将二次腐蚀新工艺应用于太阳电池工业制备中,对电池输出参量进行检测分析。结果表明,经过二次腐蚀工艺处理的太阳电池开路电压(VOC)、短路电流(JSC)和效率η均比采用一次腐蚀工艺的太阳电池有不同程度的提高,制成的太阳电池最高效率为14.93%。     

变形加工中的小批量特殊产品的制造--新的挑战和机遇

介绍了适合于生产小批量和差别化变形纱的变形加工设备，提出了由可以进行独立操作的单元机组合成整机的柔性生产新概念。     

提高变形产量的方法

介绍了采用高温加热管和强制冷却带缩短丝条变形区长度的方法.改进后的变形机可改善变形丝的质量,使加工速度提高40%～50%.     

Picosecond Laser Surface Texturing of a Stavax Steel Substrate for Wettability Control

In this investigation, a picosecond laser was employed to fabricate surface textures on a Stavax steel substrate, which is a key material for mold fabrication in the manufacturing of various polymer products. Three main types of surface textures were fabricated on a Stavax steel substrate: periodic ripples, a two-scale hierarchical two-dimensional array of micro-bumps, and a micro-pits array with nano-ripples. The wettability of the laser-textured Stavax steel surface was converted from its original hydrophilicity into hydrophobicity and even super-hydrophobicity after exposure to air. The results clearly show that this super-hydrophobicity is mainly due to the surface textures. The ultrafast laser-induced catalytic effect may play a secondary role in modifying the surface chemistry so as to lower the surface energy. The laser-induced surface textures on the metal mold substrates were then replicated onto polypropylene substrates via the polymer injection molding process. The surface wettability of the molded polypropylene was found to be changed from the original hydrophilicity to super-hydrophobicity. This developed process holds the potential to improve the performance of fabricated plastic products in terms of wettability control and easy cleaning.