镁合金加工技术的现状与发展

主要叙述了镁合金加工技术的现状与最新进展，分析了镁合金压铸成形、半固态铸造、锻造等工艺的变形特点及关键技术，并对镁合金加工技术的发展趋势进行了展望。     

Edge Blunting of Hard Alloy Cutter Blade for Cutting Chemical Fibers

IntroductionIn order to blend with natural fibers such as cotton andwool ,and with other types of chemical fibers for spun yarnproduction, continuous tow after drafting , cri mping andther mosetting should be cut into staple fibers of prescribedlength with cutter blade . Sharpness of cutter blade wouldbe decreased gradually (being called as blunting) in thecourse of cutting , which would greatly influence the staplequality and the production efficiency . So it is mostsignificant for the chemic…     

Material Removal Behavior and Surface Integrity in Grinding of Ultrafine-Grained WC-Co Materials

Due to the excellent combination of wear resistance and fracture toughness,the ultrafine-grained WC-Co composites can significantly improve the durability and reliability of industrial tools.However,the grinding of ultrafine-grained WC-Co remains a challenge.In order to provide an experimental basis for improving grinding quality of ultrafine-grained WC-Co,a series of surface grinding experiments on ultrafine-grained WC-Co hardmetals were conducted by diamond wheel under various grinding conditions,and the material removal behavior and surface integrity in grinding of ultrafine-grained WC-Co materials were characterized by means of scanning electron microscopy(SEM),X-ray microstress analyzer and surface roughness analyzer in this paper.The results indicate that the material removal behavior in grinding of ultrafine-grained WC-Co materials is determined not only by the abrasive grain size on the wheel,but also by the depth of cut.The roughness values of ground surface increase with increasing grit size of diamond wheel,and increase initially,then decrease with increase in depth of cut.Grinding causes the residual compressive stress in the surface layer of ground cemented carbides under various grinding conditions;the magnitude of residual surface stress increases with increasing grit size of diamond wheel,and isn’t changed obviously along with the change of depth of cut.     

降低涤纶短纤维切断刀成本的技术途径

分析了国内外涤纶短纤维切断刀的质量要求，材料和使用性能，提出了降低切断刀成本的技术途径。     

Technique for Measuring the Sharpness of Staple Fiber Cutter Blades

Introduction Duringtheproductionofstaplefibers,thecutting edgesharpnessisanimportantfactortothestaplequality.Thedullbladesareviabletomakedefectssuchasover lengthfibers,fiberclump,etc,whichwillcauseproblems inthefollowingtextileprocessing,sothehighqualityofcutterbladesisnecessaryintheproduction.Butforthe quantitativemethodinmeasuringsharpness,therestillhas notbeenanywidelyvsed.Thetraditionalwayisdoneby cuttingtapeorsomethingalikewithitbyhands,butfor thedifferencesofindividuals,themeasurementr…