论文部分内容阅读
用真空烧结的方法成功制备了具有优异性能的WC-Fe-Ni-Co硬质合金,研究了烧结温度和烧结时间对硬质合金组织和性能的影响。结果表明:随着烧结温度的升高和烧结时间的延长,合金的晶粒尺寸逐渐增大,矫顽磁力逐渐降低。在较低的烧结温度下合金中存在大量的孔隙,并且有不均匀粘结相分布,当烧结温度升高到1380℃,合金具有最小的孔隙度和最高的硬度、抗弯强度和断裂韧性。随着烧结温度的继续升高,合金的孔隙稍微变大,力学性能稍微减小。合金在1380℃下烧结30 min基本达到致密,但有部分粘结相聚集出现,随着烧结时间的延长硬度逐渐降低断裂韧性和抗弯强度逐渐升高。当烧结时间为60 min时,合金均匀性最好,具有最高的抗弯强度,继续增加烧结时间抗弯强度稍有降低。WC-Fe-Ni-Co硬质合金在1380℃下烧结60 min具有最佳的力学性能,其硬度、断裂韧性和抗弯强度分别为935 MPa,22.47 MPa·m1/2和2896 MPa。
The WC-Fe-Ni-Co cemented carbide with excellent properties was successfully prepared by vacuum sintering. The effects of sintering temperature and sintering time on the microstructure and properties of cemented carbide were investigated. The results show that with the increase of sintering temperature and sintering time, the grain size of the alloy gradually increases and the coercivity gradually decreases. At lower sintering temperatures, there are a large number of pores in the alloy and an uneven distribution of binder phase. When the sintering temperature is raised to 1380 ℃, the alloy has the lowest porosity and the highest hardness, flexural strength and fracture toughness. With the sintering temperature continues to rise, the alloy pores slightly larger, slightly reduced mechanical properties. The sintering of the alloy at 1380 ℃ for 30 min basically reached compactness, but some agglomeration of binder phase appeared. With the extension of sintering time, the hardness gradually decreased and the fracture toughness and flexural strength gradually increased. When the sintering time is 60 min, the alloy has the best homogeneity and the highest flexural strength. The bending strength decreases slightly when the sintering time continues to increase. WC-Fe-Ni-Co cemented carbide sintered at 1380 ℃ for 60 min has the best mechanical properties, and its hardness, fracture toughness and flexural strength are 935 MPa, 22.47 MPa · m1 / 2 and 2896 MPa, respectively.