What role does phosphor bronze play in diamond segment powder?

Copper-based segment is a commonly used diamond segment. The sintering temperature of the copper-based segment is generally about 700 degrees Celsius. But when iron powder and some other metal powders are added to the copper-based segment, the sintering temperature will continue to rise. In such a case, the diamond will continue to oxidize as the sintering temperature increases. When the sintering temperature of the diamond segment reaches above 850 degrees Celsius, the oxidation becomes more intense. In general, the sharp oxidation of diamond will eventually lead to the decline of the cutting performance of the segment.

In addition, the adhesiveness of copper elements and diamonds in copper-based segments is weak. If copper elements cannot form alloys, the copper-based segments will have poor holding power. For diamond, the matrix with insufficient holding power will form a great waste of diamond.

Therefore, adding phosphor powder to copper-based segments or other diamond segments containing copper powder has become a research direction. It has been found that copper powder and phosphorus powder can greatly reduce the sintering temperature of the diamond segment, and the sintering can be completed at 400-460 degrees Celsius. Such a sintering temperature can greatly improve the stability of the diamond in the segment. The eutectic reaction of copper and phosphorus occurs quickly, and the carcass is strengthened, so that it has strong wear resistance, hardness and impact strength.

Of course, the combination of phosphorus and copper can also greatly improve the poor  adhesiveness of copper powder and diamond. The copper-phosphorus alloy will greatly increase the holding force of the segment metal bond on the diamond, so that the cutting ability of the segment will be greatly improved.

The above is a way for copper phosphorus powder to be sintered in a traditional way. However, with the development of metallurgy technology and powder alloying technology, people began to use copper-phosphorus prefabricated metal powder to improve the production process of diamond segments.

Diamond tools have excellent processing capabilities for various hard materials, especially in various fields such as stone, ceramics, geology, machinery, and national defense. As the diamond tool industry continues to develop in the direction of high efficiency, energy saving, stability and controllability, elemental metal powder is gradually replaced by pre-alloyed powder, which greatly promotes the performance improvement of diamond tools. Pre-alloyed powder is made of alloy powder with a specific particle size by pyrometallurgy and other methods according to the designed composition ratio. Since each powder particle contains various metal elements that make up the alloy, the powder composition has good uniformity. High sintering activity can effectively avoid the segregation of diamond tool matrix elements and improve the comprehensive performance of the tool.

Copper-phosphorus pre-alloyed powder, as a brazing powder, is widely used in the field of copper and copper alloy brazing. Phosphorus is a self-fluxing element that can reduce metal or powder surface oxides during brazing and sintering. Stabilizing the production process and product quality and adding phosphorus can significantly reduce the melting point of the alloy and increase the fluidity of the alloy; In addition, because phosphorus is almost insoluble in copper, hard and brittle Cu3P compounds are easily formed during the sintering process of copper-phosphorus pre-formed gold powder. At the same time, it also has Adhesiveness to elements such as iron, cobalt and nickel commonly used in diamond tool matrixes and can form brittle compounds. Therefore, adding copper-phosphorus pre-alloyed powder to diamond tools can improve the density, wear resistance and self-sharpening of the carcass.

We added copper-phosphorus pre-alloyed powder to the matrix of diamond tools to study the influence of copper-phosphorus pre-alloyed powder on the comprehensive performance of the metal bond, and analyzed the microstructure mechanism to verify the presence of brittle compounds dispersed in the metal bond of copper-phosphorus pre-alloyed powder, which is conducive to improving the sharpness and cutting efficiency of diamond tools, and at the same time improving the comprehensive performance of diamond tools.