Hard metals are considered composite materials and are made up of mostly tungsten carbide or other carbides and up to 6-10% of cobalt, iron, or nickel, which act as binding agents. The presence of hard materials as small particles held together by a binding metal matrix makes hard metals tougher than pure metals but also more fragile. These tungsten carbide metals have an average Brinell hardness value of 1600 HV, 10 times more than that of mild steel, and they’re often used for mounting tools and machining parts.
In this article, we detail the unique physical, chemical, and mechanical properties of hard metals and how to best utilize recycled material resources to save money and combat supply chain disruptions.
Unique Properties of Hard Metals
Along with high strength, hard metals have fine microstructures that make them a good choice for manufacturing cutting tools with sharp edges. Hard metals display thermal conductivity about twice as high as that of high-speed steel. They offer excellent corrosion resistance under a non-acidic environment, and this corrosion resistance can be further improved by using Ni-base alloys or alloy binder phases, which are inherently corrosion-resistant.
Typical compressive strength and tensile strength values of a hard metal are 4-8 kN mm-2 and 2.4 kN mm-2, respectively. With such a high compressive strength, they are used in diamond manufacture as anvils and hot rolls for metallic materials.
The typical hardness can vary between 1000 to 2000 HV30 (Vickers hardness) by changing compositions at elevated temperatures, also known as hot hardness. In the absence of any strength-limiting defect, hard metals have fatigue strength and toughness that are much higher than other hard materials like ceramic.
Depending on the binder phase content, hard metals are slightly ferromagnetic and are good conductors of electricity.
General Applications of Hard Metals
Tungsten carbide is the main ingredient for tungsten carbide powder, which is further used for making cemented carbide, cermet, diamond tools, and gas diffusion electrodes. Carbide, in combination with other metals such as nickel, iron, or silver, forms special industrial alloys. These alloys are good for use in various construction, electronics, and aeronautical applications.
Cemented carbide is used in various cutting tools and abrasion-resistant tools such as end mills and mill inserts. Even hard carbides are gaining popularity for crafting wedding rings, pendants, and other jewelry. Hard metals are also used in the blades of surgical tools due to their excellent resistance to pitting and rusting.
Hard metals are commonly used in:
- Replaceable cutting tool chips.
- Saw tips.
- Drill bits.
- End mills.
- Metallic molds.
- Surgical blades.
- Jewelry items.
Recycling Tungsten Carbide Tooling
Tungsten is the main element in most of today’s hard metals and is heavily sourced from China. However, China’s new mining policies are limiting tungsten’s healthy global supply, forcing manufacturers to constantly look for alternatives. In this regard, recycling is an obvious choice for resource conservation.
Recycling used or broken CNC machining tools is a trending practice amongst fabricators and manufacturers, as recycled tungsten carbide is always in demand and is cost-effective, even in small quantities. If your production process generates a large amount of broken or worn CNC drill bits, you can utilize a rural recycling option or contact a local metal scrap recycler to see if they accept them. If they do, you can either ship it to them or request a scrap pickup service to optimize your recycling costs.
In this regard, the best way to offset shipping costs is to collect different types of scrap metals in separate containers. For example, apart from tungsten carbide, your process may also generate scrap metals like aluminum and ferrous metals like iron and steel. If you mix them, your metal recycler will likely price the container according to the cheapest metal. To help you value your metal scraps accordingly, it’s beneficial to partner with a local metal supplier that can offer large containers to sort each specific metal into.
Purchase and Recycle from a Reliable Metal Supplier
For more than two decades, Industrial Metal Service has been a top metal supplier and recycler for San Francisco Bay Area manufacturers, fabricators, and machine shops. We also can ship to and recycle from those located nationwide who do not have the benefit of a local metal supplier.
Apart from recycling tungsten carbide drill bits and scrap, we also recycle other ferrous and non-ferrous metals, including aluminum, copper, steel, and specialty alloys such as titanium and Inconel. For easy transport from local machine shops and warehouses, we can provide 55-gallon barrels, 4x4s, 4x6s, and roll-off services to maximize convenience. We can also customize containers for your specific recycling needs and volumes.