Abstract: The Ni-Cu-C solid selflubricating materials were prepared by melting method and the spheroidization effect of rare earth magnesium on graphite of Ni-Cu-C was studied. The results show that with the addition percent of Cu within 0-50%, the spheroidization effect of 0.75% of rare earth magnesium on the graphite during crystallization is effective. After the graphite being spheroidized, its nucleation density increases and distributes homogeneously. The solution of Cu improves the hardness of alloy matrix and the electrical resistivity of Ni-Cu-C alloy. The more adding of Cu has the effective spheroidization on the graphite, but reduces the content graphite. The self-lubricating properties of Ni-Cu-C alloy increase with the increasing of graphite content and spheroidization. Through dry friction and wear experiment against 45# annealed steel and GCr15 bearing steel, it was found that the friction coefficient of the Ni-20%Cu-3.5%C alloy remains stably as 0.12 and 0.13, respectively.
采用熔炼法制备出新型Ni Cu C固体自润滑材料,研究了稀土镁球化剂对Ni Cu C合金中石墨的球化作用。结果表明:在加入铜量0~50%范围内,用0.75%的稀土镁球化剂可以使结晶的石墨有效球化;石墨经球化处理后,形核密度提高,分布均匀;铜的固溶作用提高了合金基体的硬度,增大了材料的电阻率,在加入量大的情况下,对石墨有一定的球化作用,但降低石墨的含量;Ni Cu C合金的自润滑性能随石墨含量的提高及球化而得到改善;与退火态45#钢和GCr15轴承钢进行干摩擦磨损时,Ni 20%Cu 3.5%C合金的摩擦因数分别保持在0.12和0.13。
Spheroidization of graphite and properties of new Ni-Cu-C alloy
Abstract:
The Ni-Cu-C solid self-lubricating materials were prepared by melting method and the spheroidization effect of rare earth magnesium on graphite of Ni-Cu-C was studied. The results show that with the addition percent of Cu within 050%, the spheroidization effect of 0.75% of rare earth magnesium on the graphite during crystallization is effective. After the graphite being spheroidized, its nucleation density increases and distributes homogeneously. The solution of Cu improves the hardness of alloy matrix and the electrical resistivity of Ni-Cu- C alloy. The more adding of Cu has the effective spheroidization on the graphite, but reduces the content graphite. The self-lubricating properties of Ni-Cu-C alloy increase with the increasing of graphite content and spheroidization. Through dry friction and wear experiment against 45# annealed steel and GCr15 bearing steel, it was found that the friction coefficient of the Ni-20%Cu-3.5%C alloy remains stably as 0.12 and 0.13, respectively.
图2 Ni-Cu-C合金(球化)与45#钢之间 摩擦因数与时间的关系 Fig.2 Relationship between friction coefficient and fraction time of Ni-Cu-C alloy(S) against 45# steel
图3 Ni-Cu-C合金(球化)与GCr15轴承钢之间 摩擦因数与时间的关系 Fig.3 Relationship between friction coefficient and fraction time of Ni-Cu-C alloy(S) against GCr15 bearing steel