硅黄铜预合金粉末在金刚石工具中的应用

采用气水耦合雾化法制备了含有质量分数0.4%稀土Ce的硅黄铜预合金粉末, 在680~720 ℃热压烧结预合金粉末, 获得了致密烧结体。通过洛氏硬度计测试烧结体硬度为HRB62~65, 使用万能力学实验机测试烧结体抗弯强度为530~550 MPa, 利用扫描电子显微镜观察烧结体基体微观组织为α相黄铜, 组织中还存在蠕虫状及花状的弥散银灰色(β'+γ)相。选择添加质量分数20%的硅黄铜预合金粉末配方(铁粉+铜粉+锌粉+预合金粉末)制备花岗岩切割用金刚石刀头, 与单质粉末混合配方(铁粉+铜粉+锌粉)制备的刀头相比, 添加硅黄铜预合金粉末的刀头硬度增加22%, 抗弯强度降低8%, 刀头锋利度和使用寿命整体提升, 胎体磨粒夹杂减少, 并出现大量排屑沟槽。

Application of silicon brass pre-alloyed powder in diamond tools

The silicon brass pre-alloyed powder with 0.4% Ce by mass was prepared by gas-water coupling atomization method. The dense sintered body were obtained by hot pressing sintering at 680~720 ℃. The hardness of the sintered body is HRB 62~65 tested by Rockwell hardness tester, and the bending strength is 530~550 MPa tested by the universal testing machine. The microstructure of the sintered body is consisted of the brass phase (α phase) and the vermicular and flower-like dispersed silver gray (β′ + γ) phases observed by scanning electron microscope. The diamond cutting segment for granites were prepared by the mixed powders of iron powder + copper powder + zinc powder + 20% silicon brass pre-alloyed powder by mass. Compared with the cutting segment prepared by the elemental powders (iron powder + copper powder + zinc powder), the hardness of the cutting segment prepared by the mixed powders with silicon brass pre-alloyed powder increases by 22% and the bending strength decreases by 8%. The sharpness and service life of the cutting segment with silicon brass pre-alloyed powder were improved, and the matrix was characterized by the reduction of abrasive inclusions and a large number of chip removal grooves.