2023 marks the 100-year anniversary of the invention of cemented carbide. This class of alloys, known for their ability to withstand high temperatures and fast machining, are in fact the foundation of many modern machine tools.
The success of high-speed steel led the industry to develop further, resulting in the invention of cemented carbide. On March 30, 1923, Karl Schröter, the then head of R&D at Osram filed the first patent “Gesinterte harte Metallegierung und Verfahren zu ihrer Herstellung” (DE420689). The material was originally intended for drawing dies in the light bulb industry, but later cemented carbide was developed and tested for cutting tools. As such, it was introduced at an exhibition in Leipzig in 1927. Fine carbide particles are cemented into a composite with a metal binder to produce cemented carbide. The most common carbides include tungsten carbide (WC), titanium carbide (TiC) and tantalum carbide (TaC), with cobalt and nickel often used as the binding metals.
The Sandvik Coromant brand name was established in 1942, with its sole aim to offer modern cutting tools using cemented carbide as the base. Sandvik Coromant’s first cemented-carbide tools for metal cutting were manufactured the following year, and as industrialisation took off in the fifties and sixties, demand only continued to grow.
In 1969, Sandvik Coromant became the first in the world to offer ceramic-coated cemented carbide inserts. The ceramic ‘Gamma Coating’ greatly improved both the wear and heat resistance of the tools, increasing metal-cutting performance by as much as 50 per cent. Coromant continues to develop its cemented carbide offering, developing new grades and drills for a variety of industries, with its GC 4225 cemented-carbide grade becoming the best-selling grade in 2005.
Finite materials
But what about the future of cemented carbides? Central to the production of cemented carbides are metals like tungsten and cobalt, but these resources are in limited supply. Cobalt, for example, is a common component in lithium-ion batteries, valuable in extending battery life. But soaring demand combined with mining challenges means we could see shortages as soon as 2028.
To protect these finite resources, it’s imperative that manufacturers and suppliers play their part in working sustainably. This could be through repairing and refurbishing old tools to give them a second, or even a third life. Tools that are completely unusable can be sold through buy-back programmes, with the scrap being recycled into new material.
Looking ahead
The availability of the raw materials will be a factor in the future of cemented carbides. Despite big leaps in innovation, older cutting tool materials like high speed steel still play an important part in the overall market. It’s clear that even in its 100th year, cemented carbide is still a vital cutting tool material for many industries.