The Effect Of Re On Microstructure And Properties Of Ag-Cu-Ni Alloy

AgCuNi alloy provides with both favorable electrical properties and nice mechanical properties, so that it has been widely used as low load electrical contact materials. But it also has some disadvantages such as low recrystallization temperature, low strength and low hardness, these drawbacks limit its application in the field of micro-motors. In this thesis, we added rare earth elements to optimize the material's microstructure, and increase its service life. The microstructure and phase morphology measured by X-Ray diffraction, optical microscopy and scan electron microscopy, mechanics and electrical properties measured by micro Vickers hardness tester and resistance meter.The results show that, alloy grain size gradually decreased with the increasing content of yttrium element, and alloy grain size increased with increasing content of lanthanum; the hardness of AgY alloy gradually increased with increasing the content of rare earth elements, and the effect of addition of La in AgCuNi on the hardness is insignificant; and the mechanical properties superior to the traditional AgCuNi alloy.The electrical performance tests show that, with same mass percentage, resistivity of AgLa alloy is less than that of AgY alloy. In the case of cast silver alloys, the resistance is significantly increased with increasing yttrium content, while the resistivity of AgLa alloy does not change significantly; resistances of AgLa alloy and AgY alloy both decreased after annealing.