Page 35 - ISCAR_WORLD_2021

MACHINING Composites are multicomponent materials.
When compared with a traditional engineering
material, such as steel or Aluminum, composites
workpieces are nearer-to-net shape and do not
require significant material removal. Nevertheless,
EXOTICA the components of a composite have different
properties, and when combined, they produce a
heterogeneous structure that makes machining
problematic. The process of machining composites
differs from machining metals and it often looks
more like shattering than cutting. High composite
abrasiveness can lead to intensive tool dulling,
and various performance problems such as a
degradation of accuracy or non-repairable
Mainstream engineering materials are machining defects.
iron-based alloys such as steel, stainless
steel, and cast iron. Another group of An impressive leap forward in 3D printing, which
regularly used materials includes alloys may significantly diminish machining operations,
based on nonferrous metals, such as looks very promising. But there is one "exception",
aluminum alloys, brass, and bronze. which still limits taking full advantage of the
In addition, there are exotic types of considerable increase of machine tool capabilities.
material that were developed to answer This "exception" is the cutting tool. Despite the
specific demands. These exotic materials distinct progress, cutting tools remain the bottleneck
feature a dedicated application; they are for machining efficiency. Hence, the plans of a
rare and not commonly used and are breakthrough in the productive machining of exotic
generally more expensive to fabricate.
materials have much to do with the cutting tool.
Recent ISCAR developments, which were introduced
A strict agreed definition of an exotic material
does not exist. Many experts refer to them as during the last years, give a good example of such
metals like Beryllium, Zirconium, etc. and their products and ISCAR’s attempt to resolve the existing
alloys, ceramics, composites, and superalloys. bottleneck and find new ways to move forward.
When considering the use of structural
materials, superalloys and composites should
be distinguished first. The metalworking industry
mainly deals with these types of materials due
to several reasons, one of which is machining
exotic materials is problematic. Superalloys, or
more specifically, high temperature superalloys
(HTSA), are intended for operating under a
heavy mechanical load in combination with
high temperatures. They are largely used in gas
turbines and in various valves and petrochemical
equipment. The "exoticism" of superalloys is their
metallurgical design, which provides high creep
resistance to keep strength at high temperatures.
According to the main component, HTSA
can be divided into three groups: Nickel (Ni)-,
Cobalt (Co)-, and Iron (Fe)-based superalloys. A
superalloy chemistry, especially in case of Ni- and
Co-based HTSA, results in poor machinability.

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