In the production process of diamond segments
, the sintering process is an indispensable step, but there are two different options in terms of the machine used, one is a vacuum sintering machine and the other is an ordinary hot pressure sintering machine. Is a machine more suitable for the sintering of the segment? What are the advantages and disadvantages of these two machines?
The principle of the vacuum sintering machine is the vacuum liquid phase sintering method. In a closed vacuum environment, according to the different cutting objects, the matrix formula of the copper and iron-based segment is designed, and the low-melting copper-based pre-alloy powder is used as the binder phase. , And adding active metal powders such as titanium, chromium, zinc, tin, aluminum, etc. to improve the bond between the matrix and the diamond, and through continuous adjustment of the metal ratio, these materials have a high-strength bond phase. In a vacuum environment, the content of these basic metal powders has a great influence on the performance of the segment. With the continuous increase of titanium, the bonding phase of the diamond matrix has an increased wetting ability, and the hardness of the matrix increases. The bonding force of the body to the diamond increases, and the wear resistance and density of the segment increase. The vacuum welding machine greatly reduces the influence of oxygen on the segment, and the degree of oxidation is very small. Therefore, the formulation of the vacuum sintering process is relatively simple, and the improvement of the segment cutting performance is obvious. However, in the vacuum sintering process, because the liquid flow consumes more raw materials during the vacuum sintering process, so-called vacuum sintering also needs to add some nitrogen, argon and other gases to prevent the molten metal liquid from being consumed too much.
In the process of sintering with a hot press, according to the different cutting objects, the designed copper-based and iron-based formulas, after adding some active metal elements, during the sintering process, high heat can quickly exhaust the air in the carcass, but at a high temperature of 700 degrees Celsius, the diamond will still react with oxygen in the air, causing black carbides to form on the surface of the diamond, which will affect the cutting performance of the later segment. There is still a problem with ordinary thermo-pressure machines. During the sintering process, many gases will still react violently with the metal. The most obvious manifestation is the surface of the segment. You can see a lot in the appearance of the sintered agglomerated product. The adsorbent affects the appearance of the segment.
Regardless of whether it is vacuum sintering or hot press, in the later stage of cooling before demolding, most of the segment manufacturers will use natural room temperature cooling, but in fact, in the cooling process, if you use vacuum to make graphite mould can be cooled in a vacuum environment is the best, there are three.
First, the graphite mould is stored in the air for a long time, and the hot segment constantly reacts with the gas in the air, especially when the segment is agglomerated and not completely condensed, the excessive oxygen reacts with the segment.easy to cause the segment unstable performance.
Second, in a vacuum environment, the metal elements of the segment will be more active. During the cooling process, the metal will further merge to form new agglomerates, strengthen the structure of the segment and increase the density of the segment.
Keeping the diamond segment in a vacuum environment is equivalent to isolating these heat-generating objects. From a safety perspective, there are many cases of burns caused by the sintered segment, and safe production must be guaranteed.
Linxing Diamond Tools Co., Ltd. currently has 12 vacuum sintering furnaces, 32 hot-pressing sintering machines, and 30 vacuum cooling machines, which can fully meet the higher requirements and standards for the production of diamond segments