The engineblock production lines need high speed tapping with tungsten carbide taps. In the tapping process, the machining precision and the tool life of taps are directly influenced by tapping forces. And the paramet...The engineblock production lines need high speed tapping with tungsten carbide taps. In the tapping process, the machining precision and the tool life of taps are directly influenced by tapping forces. And the parameter optimization of tap structures is also correlated with the variation of tapping forces. Therefore, the study of tapping forces is necessary in developing new style taps. Several experiments about some novel carbide taps are performed on a vertical machining center by a Kistler dynamometer system in blind tapping both gray cast iron and ductile cast iron. And the variations of tapping forces are analyzed in tapping-in and tapping-out periods. It indicates that cutting forces hardly vary with the tap wear in tapping cast iron. Contrarily, tapping forces are closely correlated with the holding method. Besides, it also depends on the helix angle, the flute numbers and the plasticity of the work material to some extent.展开更多
Apple Inc’s new iPhones will used recycled rare earth elements in a key component,the company said.Apple said it will used recycled rare earths in its'Taptic Engine,'a part that lets iPhones mimic a physical ...Apple Inc’s new iPhones will used recycled rare earth elements in a key component,the company said.Apple said it will used recycled rare earths in its'Taptic Engine,'a part that lets iPhones mimic a physical button click despite being a flat pane of glass.The part is about one-quarter of the rare earth elements inside the iPhone models.展开更多
文摘The engineblock production lines need high speed tapping with tungsten carbide taps. In the tapping process, the machining precision and the tool life of taps are directly influenced by tapping forces. And the parameter optimization of tap structures is also correlated with the variation of tapping forces. Therefore, the study of tapping forces is necessary in developing new style taps. Several experiments about some novel carbide taps are performed on a vertical machining center by a Kistler dynamometer system in blind tapping both gray cast iron and ductile cast iron. And the variations of tapping forces are analyzed in tapping-in and tapping-out periods. It indicates that cutting forces hardly vary with the tap wear in tapping cast iron. Contrarily, tapping forces are closely correlated with the holding method. Besides, it also depends on the helix angle, the flute numbers and the plasticity of the work material to some extent.
文摘Apple Inc’s new iPhones will used recycled rare earth elements in a key component,the company said.Apple said it will used recycled rare earths in its'Taptic Engine,'a part that lets iPhones mimic a physical button click despite being a flat pane of glass.The part is about one-quarter of the rare earth elements inside the iPhone models.
