Building a house begins with laying the foundation. The strength and the reliability of the whole house depends on how strong the foundation is. In cutting tool engineering, this foundation is a cutting material. There are various types of cutting materials: cemented carbide, polycrystalline diamond, high speed steel, ceramics etc., and each type contains different grades. At various stages in metal cutting history, the introduction of each cutting material and its use has led to a significant change in the level of cutting speeds and, consequently, productivity. However, if the previous century, especially its second half, was marked by the rapid progress of tool materials, today we do not see any significant new solutions in this field. Does this mean that the development of new tool materials has already reached its peak and is experiencing stagnation?
Of course not. It is simply that the new developments are deep within the cutting material and are focused on its structure, and can be observed only with the help of scanning electron microscopy (SEM), X-ray diffraction (XRD), electron backscatter diffraction (EBCD), and other sophisticated methods. They cover a tremendously complicated world of coatings that is extremely diverse despite its very small thickness, measured only by microns.
The most commonly available cutting material today is cemented carbide, primarily coated. In terms of performance, it represents a reasonable balance between efficiency, tool life and cost. Cemented carbide, is known also as "hard metal", "tungsten carbide" or simply "carbide.” A combination of cemented carbide, coating, and post-coating treatment produces a carbide grade. Only one of these components - the cemented carbide - is an essential element in the grade. The others are optional.
Cemented carbide is a composite material comprising hard carbide particles that are cemented together by binding metal (mainly cobalt). Most cemented carbides used for producing cutting tools integrate wear-resistant coatings. There are also various treatment processes that are applied to already coated cemented carbide (for example, the rake surface of an indexable insert). New developments in cemented carbide, as a tool material, are concentrated in three directions: carbide production technologies, advanced coating methods, and innovative post-coating techniques. Considerable success has been achieved in each of these directions; this is reflected in the wealth of new products introduced to the market by leading cutting tool manufacturers.
Cutting tool customers might analyze the grades using parameters such as productivity, tool life, and performance. Indeed, the question of how a new product was created to meet customer requirements fades into the background as applicability and efficiency form the main measure of progress from the customer’s point of view.
In upgrading carbide grades, ISCAR is very sensitive to a challenge faced by the metalworking industries. In this context, ISCAR's tool material solutions, which are developed considering the trends of modern metalworking, can be quite indicative. Take, for example, difficult-to-cut materials such as titanium and heat-resistant steels and exotic superalloys. Recently, the share of their application in industry has increased significantly. Along with the aircraft industry, a traditional consumer of these materials, they may be increasingly found in power engineering, automotive and oil and gas branches. The growing usage of the materials demands technological solutions, including machinery and cutting tools. The new tools require an appropriate foundation, made of advanced cutting tool materials, to achieve the desired cutting geometry. And for the construction of this foundation, ISCAR offers its new effective "bricks" – upgraded carbide grades developed by company metallurgists in the last few years.
In milling, ISCAR has developed PVD coated IC882 and CVD coated IC5820 grades– two chocolate-color carbide grades for cutting titanium, high-temperature alloys, and stainless steel. An integral component of the grades is a post coating treatment that facilitates longer tool life, due to increased resistance to chipping, notch wear, and build-up edge formation. The IC882 grade demonstrates impressive performance when machining conditions are hard, and the advantages of the IC5820 are most fully manifested when applied to milling with pinpointed high-pressure coolant supply.
For drilling applications, the company introduced IC5500, a new grade that features a multi-layer CVD coating and a post-coating treatment to prolong tool life. Following the grade’s success, IC5500 has been utilized in milling products as well: the new round insert in cutters for machining 3D surfaces such as blades in turbomachinery, for example, are produced solely from this grade.
The PVD coated carbide grade IC806 was designed especially for turning high-temperature superalloys. As a result of the high mark that the grade received from the manufacturers of aerospace components, ISCAR expanded the application range of IC806 for laydown threading inserts.
In addition to cemented carbide, the metalworking industry consumes other hard cutting materials such as ceramics, diamond and cubic boron nitride (CBN). Their application to machining difficult-to-cut materials facilitates considerable increases in productivity. In recent years, ISCAR has enriched its cutting material range by introducing several new non-carbide grades, including the SiAlON grades IS25 and IS35 for cutting high-temperature alloys and the CBN grade IB20H for hard part turning (Fig. 1).
At the same time, customer demands are not limited to the effective machining of exotic superalloys or titanium. Steel is still the main structural material, and cutting tool manufacturers are constantly searching for the most advanced appropriate solutions, including the development of advanced cutting material grades. ISCAR also does not stand aside. An example may be the last innovation in parting and grooving: two new PVD coated carbide grades, IC1010 and IC1030, which were utilized in inserts from the TANG-GRIP and DO-GRIP families (Fig. 2). The grades are intended for machining stainless steel and steel. While the hard submicron grade IC1010 is recommended for productive parting and grooving with high cutting speed, the tough IC1030 is more suitable for interrupted cut and unstable machining conditions.
Upgrading cutting material grades is an essential component for tool manufacturers’ success, and innovations in cutting tools should have a strong foundation. This why ISCAR’s motto "to be on the upgrade" guides and inspires new tool material developments.
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