Overview of Hard Alloy Used in Rock Drilling Tools

Date: Oct. 23, 2024

What is hard alloy for rock drilling

Mining hard alloy is a superhard metal material embedded in the front end of rock drilling tools to directly work on rocks and break them. The main raw materials for manufacturing hard alloys are tungsten carbide and cobalt, both of which are rare metal mineral resources.

What is the annual usage of hard alloy for rock drilling in China

The tungsten products industry in China produces over 42000 tons of tungsten carbide hard alloy products annually, mainly used for the manufacturing of metal cutting tools, machinery and wear-resistant material components, as well as drilling tools for rock drilling. The rock drilling tool industry in China consumes approximately 11000 tons of mining grade hard alloys annually.
What are the characteristics of hard alloys used for rock drilling in practice

During the rock drilling process, the mining hard alloy embedded in the rock drilling tool must withstand dynamic loads such as high-power impact and rock wear, and the service stress conditions are much worse than those of cutting tools and wear-resistant component alloys. In use, it often presents the following situations:; Firstly, the usage cycle is short; Taking a 45mm diameter top hammer rock drill bit as an example, the drilling speed in medium hard rocks with F=14-16 is 0.7-0.8 meters per minute, while the normal service life of a general drill bit is between 120-150 meters. Eventually, it is scrapped in the form of alloy fracture, wear, tooth loss, and wear of the drill bit steel shell. Secondly, the product utilization rate is low; During the rock breaking process, only the end of the hard alloy head works on the rock, and most of the volume is fixed in the steel body as a support. From the beginning of rock drilling to the scrapping of drilling tools, less than 15% of the total weight of the alloy is actually consumed during the rock drilling process. Thirdly, the recycling rate of scrap alloys is low. Unlike other tungsten carbide hard alloy products, about 65% of the entire volume of mining alloys is embedded in the steel used as support and fixation in the drill bit body. After the drill bit is scrapped, the residual alloy remains in the blind holes of the steel body, making extraction very difficult and costly. If it is treated as scrap steel together with the drilling tool steel body. Tungsten carbide alloy, as a high melting point heavy metal, can also have adverse effects on the purity and impurity content of steel during scrap smelting. The fourth reason is that the sales price of alloys is low. Due to the short service life and high consumption of rock drilling tools, they have always been in a cheap trend in the market price. Therefore, the price of mining cemented carbide is also the lowest average market price among all tungsten carbide cemented carbide products.