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以六方BN(hBN)、NiCl_2和NaCO_3为原料,采用沉淀法制备镀镍hBN粉末,并采用粉末冶金法制备Ni-20Cr/hBN自润滑复合材料。研究了镀镍hBN粉末对Ni-20Cr/hBN复合材料密度、孔隙率、硬度、抗弯强度以及摩擦磨损性能的影响。结果表明:固体润滑剂hBN表面镀Ni可提高Ni-20Cr/hBN复合材料的致密度和力学性能。其密度由5.43 g/cm~3提高至5.68 g/cm~3,孔隙率由22.13%降低至18.55%,抗弯强度由70.48 MPa提高至99.42 MPa,硬度由18.82 HB提高至21.02 HB。采用镀镍hBN粉末制备的Ni-20Cr/hBN复合材料具有宽温带减摩性,在常温和600℃下测试时,摩擦系数变化不明显,而在600℃时磨损率由462.18 mg/min降低至204.4 mg/min。
Ni-20Cr / hBN self-lubricating composites were prepared by precipitation method using hexagonal BN (hBN), NiCl 2 and NaCO 3 as raw materials. The effects of nickel-coated hBN powder on the density, porosity, hardness, flexural strength and friction and wear properties of Ni-20Cr / hBN composites were studied. The results show that the Ni-20Cr / hBN composites can improve the density and mechanical properties of the hBN surface. Its density increased from 5.43 g / cm ~ 3 to 5.68 g / cm ~ 3, porosity decreased from 22.13% to 18.55%, flexural strength increased from 70.48 MPa to 99.42 MPa, and hardness increased from 18.82 HB to 21.02 HB. Ni-20Cr / hBN composites prepared from nickel-plated hBN powders exhibit broad-band antifriction properties. When tested at room temperature and 600 ℃, the friction coefficient does not change significantly. However, the wear rate decreases from 462.18 mg / min to 204.4 mg / min.