Hybrid process for texturization of diamond wire sawn multicrystalline silicon solar cell

Acid texture is difficult for diamond wire sawn (DWS) multicrystalline silicon (mc‐Si) wafer owing to the inhomogeneous distribution of damage layer on the surface. In this article, metal‐assisted chemical etching (MACE) has been selected for introducing a porous seeding layer to induce acid texturing etching. SEM results show that the oval pit structures coverage get obvious improvement even on the smooth areas. Owing to the further improved light absorption ability by second MACE and nanostructure rebuilding (NSR) process, nanostructured DWS mc‐Si solar cell has exhibited a conversion efficiency of 17.96%, which is 0.45% higher than that of DWS wafer with simple acid texture process. (© 2016 WILEY‐VCH Verlag GmbH &Co. KGaA, Weinheim)     

金刚石锯片在锯切过程中的受力与失效分析

对金刚石锯片在锯切过程中的受力及弧区内直接参与切削的金刚石数量进行了测量和估算,并分析了节块表面抛光和微破碎金刚石比例与锯片寿命和效率之间的关系,结果表明：单颗粒金刚石的受力远低于其静压强度;其低强度失效的原因是锯切过程中金刚石晶体内产生的热应力。     

Numerical and experimental investigations of micromechanical processes during wire sawing

In the following paper the mechanisms of the slurry-based wire sawing process at micro level are studied by numerical simulations. For the simulation a new approach in simulating the wire sawing process is presented. A discrete element method (DEM) with polyhedral particles is used to simulate the movement of the abrasive particles as well as the wire during the process. The results are verified by direct observations of the sawing channel of an experimental setup. The presented numerical model is applied for a detailed study of the influence of different process parameters.     

锯切花岗石过程中金刚石节块磨损特征及影响因素分析

在已有的节块磨损规律的基础上，对锯切花岗石过程中的金刚石及其固位载体－粘合剂的磨损规律进行了研究。通过实验，跟踪观察了不同金刚石节块在各种加工条件下的磨损状态。结果表明；金刚石的工作状态与节块的使用性能有良好的对应关系，金刚石的微破碎和完善晶型比例越高节块耐磨性越好；宏观破碎和脱落比例越高节块耐磨性越差。金刚石的粒度，含量，品级，粘合剂和金刚石的匹配以及锯切用量组合等均明显影响锯切效果。     

锯切过程中花岗石与金刚石间的摩擦效应

通过测量锯切力和计算锯切比能,获得了多种条件下的比能与单颗磨粒平均载荷的试验,从能量角度探讨了花岗石的锯石的锯切机理,并建立了单颗磨粒平均载荷与磨粒纵向切削面积平均值之间,单位宽度功率消耗与滑擦面积之间的对应关系。结果表明,锯切过程中能量主要消耗于花岗石与金刚石间的摩擦,由于单颗磨粒向切削面积平均值同时包含了磨粒切削深度与弧长的影响,更适用于描述锯切过程。锯切中锯切深度和材料去除率等因素的影响均可     

超声振动对光学玻璃加工的锯切力特征研究

超声振动辅助方法已在各种硬脆性材料的加工工艺中得以应用,其优异的加工能力和效果已得到广泛证明。本研究中通过采集有无超声振动条件下锯切光学玻璃的平均锯切力以及单颗金刚石磨粒划擦实验下的力信号,对不同工艺条件下的平均锯切力、单颗磨粒受力特征进行分析。同时通过扫描电镜观察对应力信号下工件与工具加工后表面形貌,进一步通过超声振动下材料去除机理解释超声振动对锯切力影响。结果表明：与传统锯切工艺相比,超声振动辅助使得单颗磨粒划擦过程中的受力降低引起平均锯切力的降低;超声振动改变普通锯切下材料的去除方式;同时可使工具保持良好的锯切状态,降低光学玻璃材料的锯切力比,改善其可加工性。