Advanced Powder Technology, Vol.29, No.6, 1433-1438, 2018
Microstructure and thermal decomposition property of Ni-P/Cr2N composite powder by electroless plating
Cr2N is the most promising blowing agent for the preparation of steel foam using melt foaming method. In this work, to obtain a blowing agent with suitable density and gas decomposition characteristics for steel melt foaming, Ni-P/Cr2N composite powder was prepared by electroless plating. The surface morphology, phase, coating thickness, density and decomposition characteristics of Ni-P/Cr2N composite powder were analyzed. The results indicate that the surface of Ni-P/Cr2N composite coating powder is covered by the high nickel and low phosphorus layer which has a dense and uniform cell structure. The decomposition rate of the Ni-P/Cr2N composite powder is 7.46 mW/mg slower than that of the uncoated Cr2N powder at 1107.4 degrees C. When the plating time is 30 min, the thickness of Ni-P layer reaches 2.86 mu m, the density of the Ni-P/Cr2N composite powder is 7.45 g/cm(3), and maximal decomposition rate temperature reaches 1500 degrees C. These findings suggested that Ni-P/Cr2N composite powder meets the requirements of decomposition temperature and density of the blowing agent used to produce steel foam with a uniform pore structure by the melt foaming method. (C) 2018 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.
Keywords:Steel foam;Ni-P/Cr2N composite powder;Electroless plating;Microstructure;Thermal decomposition property