As far back as 7,000 BC, humans began to realise that they could shape copper into several shapes to be used as tools. As time went on, they recognised that tools made from copper tend to last even longer than tools made from stone.

Since then, the use of metal tools has become widely accepted in all parts of the world. Presently, using metal tools involves a lot of decisions, from choosing the right metal to selecting the most suitable hardening process.

Choosing a hardening process for your tools has to be your top priority if you want your tools to last long. There are several methods for hardening metal tools, each with its advantages and disadvantages. But for the best results, the use of vacuum-hardened cannot be overlooked.

For those who are new to this hardening process, this guide will help introduce you to the process of vacuum hardening. You also get to find out the benefits that make vacuum hardening a good choice for your metal tools.

What Is Hardening Process?

As the name says, the metal hardening process is a process used to harden or improve the toughness of metal tools. There are several methods used to carry out this process.

Generally, we often see metal objects as hard and rough materials that can withstand certain conditions of use. However, the toughness of these metal tools is often attributed to the hardening process of the metal. It has little to do with the metal itself.

Many metal hardening processes involve the use of temperature and other factors to improve the durability of the metal. Most times, the metals are heated up and then cooled down at the end of the process.

The hardening process of metals features a series of steps with each step serving a unique purpose. Some steps involve changing the chemical properties of the metal especially with the use of heat and soaking. Most times, these chemical changes are either permanent or return to their initial state once the metal cools down.

The term soaking in metal hardening has no relation to the regular soaking in liquid. Soaking in metal hardening involves leaving the metal to soak in the heat for a particular time. Once soaking is complete, the metal is cooled down, allowing it to attain its fully hardened form.

How Vacuum Heat Treatment Works

The vacuum hardening process, like many other metal hardening processes, involves heating. The distinctive feature is that it is carried out in a vacuum.

The reason for using a vacuum is to eliminate as much air as possible from the environment. This provides a better and predictable outcome for the hardening process. When the metal is placed in a sealed chamber, the vacuum pump does the job of eliminating the air. With proper maintenance of the chamber, you can prevent the leakage of air into the chamber while the hardening process is ongoing.

Benefits of Vacuum Hardening

As we all have grown to know, the air is composed of a mixture of different elements and molecules. These elements react with all types of metals in unique ways. The air also contains different moisture in combination with carbon dioxide, oxygen, and other gases. At regular temperature, these gases may not react or at least have a visible effect. However, once the temperature is increased, the reactions between these gases, the air, and the metal become visible.

With the vacuum hardening process, the effects of these reactions are nullified by taking out all the air from the chamber. This gives you a more controlled reaction with a predictable outcome. Other hardening processes utilize other methods to curb unwanted reactions.

Compared to other hardening processes, the vacuum metal hardening process offers the most controlled environment. For this reason, it provides the best result for your metal tools. Below is a list of the benefits of using a vacuum hardening process.

1. No Discoloration

When using the vacuum hardening process, you automatically limit the level of impurities capable of causing discoloration or scalding.

Scalding or discoloration of your metal during a hardening process reduces its usability as well as your chances of reselling. This can have a huge negative impact on businesses involved in these processes. 

Even with the use of non-reactive gas or molten salt, many hardening processes still fail to prevent such occurrence. However, when using vacuum hardening, there is zero chance of discoloration or scalding.

2. Avoid Oxidation

Oxidation is known to be the major cause of rust in metals. With other non-vacuum hardening processes, there is a high risk of oxidation which can lead to rust. Oxidation during the metal hardening process can also lead to the formation of cracks on the metal.

Oxidation makes metals weak and less durable. With vacuum hardening, there is no chance of oxidation occurring since there is no exposure to air or oxygen. 

3. Improve Multiple Properties

The vacuum hardening process doesn’t just prevent your metal from damage, it also improves the state of your metal. It does this by improving both the physical and chemical properties of the metal.

Hardening your metal with the vacuum process increases its durability, making it less susceptible to corrosion. Its elasticity as well as its sheer and tensile strength will also show a noticeable increase. In other words, the vacuum hardening process makes your metal suitable for a wide range of uses.

4. Environmentally Friendly

With the rise in environmental pollution, it’s no surprise that people opt for a better way to carry out activities like metal hardening. Luckily, the vacuum hardening process happens to be environmentally friendly. Using an environmentally friendly process improves customer loyalty while providing a safe working environment for your staff.

There are a lot of dangers involved in the process of hardening a metal. However, the vacuum hardening process has little or no health or environmental hazards as it does not involve the use of toxic or flammable gases.

5. Faster Results

In terms of a quick delivery, this process stands out when compared to other processes for metal treatment. Once the metal has been hardened, you can immediately use the tool for the next phase of your production.

The vacuum hardening process eliminates the extra time used by other processes, allowing you to produce your final product faster. This improves your production time which in turn improves your business.

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