This paper reports the chemical synthesis of tungsten carbide/cobalt (WC/Co) nanocomposite powders via a unique chemical processing technique, involving the using of all water soluble solution of W-, Co- and C-precurs...This paper reports the chemical synthesis of tungsten carbide/cobalt (WC/Co) nanocomposite powders via a unique chemical processing technique, involving the using of all water soluble solution of W-, Co- and C-precursors. In the actual synthesis, large quantities of commercial-scale WC-Co nanocomposite powders are made by an unique combination of converting a molecularly mixed W-, Co-, and C-containing solutions into a complex inorganic polymeric powder precursor, conversion of the inorganic polymeric precursor powder into a W-Co-C-O containing powder intermediates using a belt furnace with temperature at about 500°C - 600°C in an inert atmosphere, followed by carburization in a rotary furnace at temperature less than 1000°C in nitrogen. Liquid phase sintering technique is used to consolidate the WC/Co nanocomposite powder into sintered bulk parts. The sintered parts have excellent hardness in excess of 93 HRA, with WC grains in the order of 200 - 300 nm, while Co phase is uniformly distributed on the grain boundaries of the WC nanoparticles. We also report the presence of cobalt Co precipitates inside tungsten carbide WC nanograins in the composites of the consolidated bulk parts. EDS is used to identify the presence of these precipitates and micro-micro-diffraction technique is employed to determine the nature of these precipitates.展开更多
采用三种不同加热方式制备了体育器材用5052铝合金锻压件,并进行了力学性能和耐腐蚀性能的测试与分析。结果表明,不同加热方式对该锻压件的力学性能和耐腐蚀性能有明显的影响。与箱式电阻炉加热相比,传送带式回火炉加热时锻压件的抗拉...采用三种不同加热方式制备了体育器材用5052铝合金锻压件,并进行了力学性能和耐腐蚀性能的测试与分析。结果表明,不同加热方式对该锻压件的力学性能和耐腐蚀性能有明显的影响。与箱式电阻炉加热相比,传送带式回火炉加热时锻压件的抗拉强度和屈服强度分别增大25%、63%,腐蚀电位正移57 m V,12 d乙酸盐雾腐蚀后的质量变化率减小64%。感应加热时锻压件的力学性能和耐腐蚀性能介于箱式电阻炉加热和传送带式回火炉加热的之间。加热方式优选为:传送带式回火炉加热。展开更多
文摘This paper reports the chemical synthesis of tungsten carbide/cobalt (WC/Co) nanocomposite powders via a unique chemical processing technique, involving the using of all water soluble solution of W-, Co- and C-precursors. In the actual synthesis, large quantities of commercial-scale WC-Co nanocomposite powders are made by an unique combination of converting a molecularly mixed W-, Co-, and C-containing solutions into a complex inorganic polymeric powder precursor, conversion of the inorganic polymeric precursor powder into a W-Co-C-O containing powder intermediates using a belt furnace with temperature at about 500°C - 600°C in an inert atmosphere, followed by carburization in a rotary furnace at temperature less than 1000°C in nitrogen. Liquid phase sintering technique is used to consolidate the WC/Co nanocomposite powder into sintered bulk parts. The sintered parts have excellent hardness in excess of 93 HRA, with WC grains in the order of 200 - 300 nm, while Co phase is uniformly distributed on the grain boundaries of the WC nanoparticles. We also report the presence of cobalt Co precipitates inside tungsten carbide WC nanograins in the composites of the consolidated bulk parts. EDS is used to identify the presence of these precipitates and micro-micro-diffraction technique is employed to determine the nature of these precipitates.
文摘采用三种不同加热方式制备了体育器材用5052铝合金锻压件,并进行了力学性能和耐腐蚀性能的测试与分析。结果表明,不同加热方式对该锻压件的力学性能和耐腐蚀性能有明显的影响。与箱式电阻炉加热相比,传送带式回火炉加热时锻压件的抗拉强度和屈服强度分别增大25%、63%,腐蚀电位正移57 m V,12 d乙酸盐雾腐蚀后的质量变化率减小64%。感应加热时锻压件的力学性能和耐腐蚀性能介于箱式电阻炉加热和传送带式回火炉加热的之间。加热方式优选为:传送带式回火炉加热。
