Aug 07, 2018
The production technology of indexable inserts is based on powder metallurgy technology. The production process is as follows: preparation of cemented carbide mixture; pressing; sintering; post-sintering treatment; coating. Although the basic processes have remained unchanged for decades, at the same time advances in science and technology have had a significant impact on the manufacture of blades.
In the past, blade blanks were often pressed by hand. Therefore, it is very difficult or even difficult to uniformly sinter the mixture compact having different compacting densities. As more and more cutting-edge automation and computer-controlled advanced industrial equipment enters the cemented carbide manufacturing industry, the technical control of the cemented carbide production process is increasingly stable, controllable and reliable. As a result, the machining performance of the produced blades becomes more and more consistent, the processing results are predictable and the machining results are not different due to the different blade numbers; the new technology also makes the sintering inserts have narrower tolerances and higher precision. The performance of cemented carbide blades has been greatly improved.
Today, a typical blade press is often a computer-controlled, highly assembled engineering device. Some press designs are also available for multi-axial compression. The extraordinary advancement from pressing technology has made it possible to produce blades with complex shapes, such as blades with very different tool tip heights (Fig. 1). Advanced pressing technology ensures a more optimized blade shape that not only ensures smooth blade surface stability and blade production, but also improves the accuracy of the blade surface (Figure 2). In addition, the application of modern computer-aided design and manufacturing technology (CAD/CAM) has also brought benefits to the manufacture of blades, making it possible to increase the blade design level and obtain better shape and precision of the pressed mold parts. And with the ability to simulate the pressing process with the final sintered product as the guide, in the initial stage of the design, the pressing and sintering results can be modified from the design point of view to promote the successful development of new blades.
Control of the advanced technology of blade sintering also helps to improve the quality of the blade during the production process. Process control is performed during the sintering process to obtain a gradient cemented carbide substrate of non-uniform structure, ensuring a thin layer of cobalt-rich layer on the surface of the alloy. The cemented carbide substrate with a gradient layer can block the development of surface cracks and ensure that the cemented carbide matrix has better resistance to brittle fracture and damage. Today, gradient cemented carbide substrates are often used in turning tools.