Whether you're into automobiles, planes, mechanics, or industry, you know one thing:
German. Steel.
During WWII, physicists Dr. Wehnheldt and Swiss Dr. Bernhard Berghaus developed a method of hardening steel without distortion or danger.
Since then, we've refined and mastered what they called "glow discharge" to rise to the top of the Slovenian heat treatment game.
What makes this process so important, and why do we do it?
In this article, we're going to discuss how plasma nitriding works and why it's necessary for modern steel quality.
An Alternative to Gas, Chrome Plates & Salt Baths
Although your mileage may vary, plasma nitriding is superior to other forms of case hardening in its wear resistance, sensible process, and high control.
One other form of nitriding is gas nitriding, which releases ammonia into a chamber, diffusing nitrogen onto the surface to create a solid layer.
A computerized control system for gas nitriding has been developed in recent years, allowing complete monitoring of the thermodynamic properties involved, as well as oxygen levels. (Mixing ammonia with air is... dangerous.)
Yet another alternative is salt bath nitriding, quick and extremely toxic. Much like a drunken one-night stand.
Those processes are strong in different circumstances, but plasma nitriding is nontoxic, flexible, and precise. Especially when you're dealing with iron-based materials or porous substances like sintered steel.
Plasma nitriding is usually done for gears, crankshafts, cylinders, plastic molds, auto parts, industrial tools, and other mechanical parts that need strength.
How-To: Plasma Nitriding
First, the product is sealed in a low-pressure vacuum.
The only gas plasma requires is nitrogen, but it's often done with hydrogen, argon, and methane. Unlike gas nitriding, these chemicals aren't the method's main mechanism.
Once said gases fill up the back, high-power electric fields bathe the product in a steady voltage, forming ionized molecules. This is plasma.
Iron fits like a puzzle piece to nitride, which is a form of nitrogen. So it's only natural that steel alloys should react well to the gas.
Usually, you need a particular temperature for nitrogen to be ready for this process. While we do regulate the temperature in plasma nitriding, it's the electricity that causes the reaction.
The forming plasma is visible through the window of the chamber.
The compounds that are formed in this process deposit active nitrogen onto the material, forming a solid layer with carbon.
These first layers can be about 20 microns thick, already doing wonders for your metal.
The Upper Hand
So, what is it that makes ion nitriding worth it?
It's a clean process with benefits ranging from economy to flexibility.
- No tear. Plasma ion nitriding is a distortion-free process. That means your surface won't change at all. This is because we do it at a mid-temperature which relieves the tension of steel while keeping it intact.
- No wear. Don't expect the layer to go away any time soon.It's durable and dense. No bending, rolling, or pressing will break it down easily.
- Ridiculous hardness. Hardness can increase 40x.Studies have shown it takes hardly any time to double the hardness of samples. And we prove it here all the time in our lab.
- Surface changes.While ensuring minimal changes in size or shape, we can increase the metal's resistance to friction and corrosion.
- Consistency. Plasma nitriding is a controlled process. We can do the same thing over and over again and get the same results each time. You don't have to worry about one side being coated and the other not. Unless that's what you want, which leads us to...
- Flexibility. It's simple to mask your metal.This means you can only add layers to part of the surface, as much or as little as you need.
- Eco-friendliness. The process is non-toxic, using half as much energy and gas as other methods.It's as clean as brushing your teeth.
This method of hardening is extremely efficient and dynamic.
No polishing or post-treatment is necessary for surfaces, but it can be done if you need super smooth metal.
The Cost-Effectiveness of Ion Nitriding
Compared to gas nitriding, this process takes much less time and resources.
But also, the technology and equipment behind plasma nitriding has a much higher cost.
We can deal with heavier metals this way, creating layers regularly and efficiently.
If you need a big batch with low weight, you might want to consider gas nitriding instead. Just keep in mind there's no such thing as masking in the gas process. (But we can do some partial nitriding with gas.)
Speaking of which, what are some of the disadvantages of plasma nitriding?
As we've said, the size of the furnace determines the size of your metal.
And like all things, the nitrided layer does wear with repeated contact. While it can sustain huge temperatures and last you a long time, it depends on your metal and how you're using it.
If you need to coat a variety of different metals, it'll take multiple batches, since the regulation temperature will be different for each kind.
We take great care to ensure the quality of your metal, such as preventing the hollow cathode effect. This is where "blind holes" affect the plasma nitriding process.
In reality, the disadvantages of ion nitriding are much fewer than that of gas nitriding.
What you should choose depends on your situation. What do you need to accomplish? What is your budget?
Can I Use It?
Absolutely. Some of the most common applications for ion nitriding are:
- Car parts
- Mechanical engineering parts
- Crankshafts
- Gears
- Die casting tools
- Plastic molds
- Armature equipment
The list goes on.
Very frequently, it would be impossible to create a working machine in harsh environments without nitriding.
Why not use the most eco-friendly and consistent process out there?
We've been in this industry for 40 years. We're the biggest name in heat treatment in Slovenia, and we'll continue to invest our experience in the lives of our customers.
Need help deciding which option you should choose? Let's get in touch and talk about what kind of nitriding is best for you.