铜基胎体中低熔点金属的反应特性及性能研究

Research on reaction characteristics and properties of low-melting metals in Cu-based matrix

Zn和Sn是金刚石工具胎体常用的低熔点金属。实验采用电阻式热压法制备了4种不同Zn/Sn含量的试样。通过改变Zn/Sn配比,借助力学试验机、扫描电子显微镜、X射线衍射仪,研究铜基胎体中低熔点金属的反应特性及其对烧结体性能的影响。结果表明:保持Sn+Zn总量不变,当Zn引入量由0增加到8wt%时,烧结体中Cu_(41)Sn_(11)硬脆相逐渐减少,最终消失,而Cu_(13.7)Sn+Cu_(0.7)Zn_(0.3)相逐渐增加;烧结体的硬度值由84.6HRB降至67HRB;抗弯强度由630MPa提高至736MPa;冲击韧性由5.7J/cm^2提高至26.6J/cm^2。四种试样断口均出现光亮平整的脆性断面特征和类似于塑性断裂的浅韧窝特征,但从力值-变形曲线看仍属于典型的脆性断裂行为。

Zn and Sn are commonly used in diamond tool matrix. Four kinds of samples with different Zn/Sn content were prepared by hot pressed sintering. By changing the Zn/ Sn ratio, th trix were di e reaction characteristics and properties of low melting metals in Cu based ma scussed with the help of mechanical testing machine, scanning electron micro scope and X ray diffractometer. When the total amount of Sn＋Zn kept constant, the hard brittle phase of Cull Snll decreases gradually and finally disappear as the amount of Zn increases from 0 to 8wt%. But at the same time, the content of Cu13.7Sn＋Cu0.2Zn0.3 phases increases gradually. The hardness of sintered body decreases from 84. 6HRB to 67HRB, the flexural strength increases from 630MPa to 736MPa, and the impact tough ness increases from 5. 7J/cm^2 to 26. 6J/cm^2. The characteristics of brittle fracture and plastic fracture were observed clearly at the fracture region of different specimens. But it still belongs to the typical brittle fracture behavior according to the stress strain curve.