3D Metal Printing: Oxygen Analyzers Are Essential

 

Metal 3D printing, also known as additive manufacturing, provides for the creation of complex metal parts by layering metal powders and, depending on the application, selectively sintering, fusing, or melting the powders using a high-powered laser or electron beam. This process offers numerous advantages over traditional manufacturing methods, including reduced waste, increased design freedom to create complex components, and faster production times. The industry applications of metal 3D printing are vast and growing rapidly. Metal 3D printed components are used in aerospace (for lightweight components with complex designs), automotive (for customized parts and prototypes), medical (for implants and prosthetics), and even jewelry manufacturing. The ability to create intricate metal parts with high precision has opened up new possibilities across a variety of industries.

3D Metal Printing Requires Low to Ultra-Low Oxygen Environments

3D printing processes require inert, low to ultra-low oxygen (i.e., nearly oxygen-free) environments to protect the integrity of the finished printed parts. Undue exposure to oxygen, even in small amounts, can result in various defects, such as porosity, oxidation, corrosion, and reduced mechanical properties. Porosity refers to small voids or gaps within a printed part that can compromise its structural strength. Oxidation results in surface discoloration, weakened structural integrity, and compromised part performance. Reduced mechanical properties can result from brittleness or reduced tensile strength caused by excessive oxygen exposure. In addition, dust from the metal powders can be combustible when exposed to oxygen. Some metals, such as titanium and aluminum, can burn quickly, at extremely high temperatures and, in some cases, may cause violent explosions.

To create the desired low oxygen environments, 3D metal printing facilities utilize inert gases—typically argon or nitrogen—within their build chambers. These inert gases deplete oxygen from the build chambers, creating stable printing environments, preventing fire hazards by keeping combustible dust inert, and reducing irregularities and defective elements.

Oxygen Analyzers Help Prevent Product Impurities

Oxygen analyzers are critical to monitoring and regulating oxygen levels within the build chambers during 3D metal printing operations. By utilizing a top-quality oxygen analyzer, metal 3D printer operators are able to monitor and maintain optimal oxygen levels throughout the printing process. An O2 analyzer helps ensure that printed parts are free of imperfections and meet required design specifications. Analyzers continuously track oxygen levels to provide real-time data on oxygen concentration, allowing for immediate adjustments if necessary.

PureAire Trace Oxygen Analyzers

PureAire Monitoring Systems' industry-leading line of Trace Oxygen Analyzers includes products built with both low parts-per-million (ppm), or low percent level O2 sensors, which are designed to operate effectively under continuous inert environments. The Analyzers have remote sensors that are placed directly within the build chambers to continuously monitor oxygen levels.

Depending on user needs, our Trace Oxygen Analyzers can be programmed to detect ultra-low oxygen concentrations, from as low as .0.01 ppm up to 1,000 ppm, as well as higher (albeit still low) oxygen concentrations, from 0% up to 25%. They can operate in a vacuum of 20 Torr or less, and their zirconium oxide sensor cells do not need an oxygen reference gas for proper operation. In the event of undesired changes in oxygen levels, our Analyzers will sound alarms, alerting personnel to take corrective action.

PureAire's Trace Oxygen Analyzers measure oxygen 24/7, with no time-consuming maintenance required. Our long-lasting zirconium sensors provide accurate readings, without calibration, for up to 10 years.

Titanium Demand on Rise for Additive Manufacturing Printing: How it’s Made? Titanium Plasma Atomization

                                                                                                                                      Link to oxygen sensors
Plasma atomization is used in many applications, including 3D printing. First developed in 1998, this technique has risen to become the industry standard process for creating reactive metal powders suitable for 3D printing. Learn how plasma atomization works and why you need an oxygen monitor to stay safe with plasma atomization. 

How Plasma Atomization Works

Plasma atomization is used not only in 3D printing, but in any circumstance where powder metallurgy is needed. Other uses include spray coating, cold spray, and metal injection molding. 
To pulverize metal, wire is fed through a tube, then hit by three plasma torches capable of reaching temperatures of 10,000 degrees Celsius. As the wire liquefies and melts, individual droplets shear off and fall into a chamber filled with argon gas and cooled by water. When the drops of metal hit the argon, they solidify into spherical droplets. This process produces a fine, uniform metal powder. After the wire has been transformed into droplets, the powder is sieved to ensure uniformity. This is key to the success of the 3D printing process, which relies upon fine grade, uniform powder. 

Titanium (Ti), Nitinol, Niobium, Aluminum, and other reactive metals and their alloys can all successfully be atomized through this process. Variables in the plasma atomization process allow workers to create droplets of different sizes, for different end uses.  

PureAire offers an oxygen analyzer, which many 3D printing manufacturers utilize. This device helps monitor the levels of oxygen in ppm, from 0 to 1000, while the atomization process takes place. 
It's important to keep oxygen levels low while the Ti and other base metals are being turned into powder, as this ensures the purity of the final product. Oxygen analyzers provide a continuous readout of oxygen levels inside the chamber, so your workers can ensure the highest levels of purity at a glance. 

Argon gas is used during plasma atomization because it helps ensure the purity of the powdered metal by reducing the chance for chemical reactions that might happen if oxygen interacted with the metal during the atomization. As long as the argon gas remains in the chamber where the aluminum or titanium powder is being made, plasma atomization is quite safe. Like other inert gases, argon depletes oxygen from the atmosphere. Were the argon gas to leak out of the plasma atomization chamber, employees' wellbeing could be at risk. 

Why You Need an Oxygen Monitor with Plasma Atomization

When argon escapes into the environment, it displaces oxygen molecules. Since the gas is both odorless and colorless, there is no way to detect an argon leak by sight or smell. If there are several atomization stations creating Ti or titanium powder at once, the risk increases exponentially. 
Once oxygen levels begin to drop, worker safety becomes a concern. If oxygen levels fall below the minimum set by OSHA, workers can suffer respiratory and cognitive impairment. Symptoms include dizziness, confusion, fatigue, and shortness of breath. Even a brief exposure to an oxygen deficient environment can prove deadly. 

Fortunately, an oxygen deficiency monitor can continually weigh oxygen present in the room, alerting staff before oxygen levels plunge below the OSHA threshold. This provides sufficient notification via flashing lights and loud alarms for staff to exit the room to safety. 

PureAire offers an oxygen monitor with a zirconium sensor. Unlike other sensors, this lasts with no maintenance and no calibration once the O₂ monitor is installed. The O₂ monitor and oxygen analyzer, when used together, allow for precise manufacturing of powdered metals with low risk to workers. Businesses prefer PureAire products, which are low-maintenance, cost-effective, and reliable for 10+ years. Visit www.pureairemonitoring.com to learn more about our oxygen analyzers and monitors. 

 

Argon Gas, 3D Printing, and How to Stay Safe

For the average person, Argon gas is not a topic of daily conversation, or, for that matter, any conversation, ever. It may be surprising to learn that argon is the third most common gas in the earth’s atmosphere, though most people know little about it. The word argon itself comes from a Greek word meaning ‘inactive’ because of its lack of chemical reactions. Argon is colorless, odorless, tasteless, and non-toxic, but this doesn’t mean it is completely harmless. Because it is 38% denser than air, it can displace the oxygen in an enclosed area, asphyxiating anyone inside.

When using the right safety precautions, like an oxygen deficiency monitor, argon can be very useful. It is used as a shielding gas in metal work and welding to prevent burning, and can even be used to extinguish fires. As a preservative, argon can be used to displace oxygen out of packaging to extend shelf life by preventing oxidation and spoilage. Even light bulbs are filled with argon to prevent oxidation of the filament.

One of the most modern uses of argon gas is in selective laser melting, which is a type of 3D printing. In this process of additive manufacturing, layers of a powder are bonded together using a powerful laser (as opposed to sinter bonding them). Argon is an inert gas, and relatively inexpensive, therefore it creates the perfect environment for this process to take place in. The use of argon here permits a tightly controlled atmosphere, allowing for an oxygen free environment. Using this amount of argon requires the use of an oxygen monitor for safety.

An oxygen deficiency monitor tests the percentage of oxygen in an enclosed area to ensure it is safe to breathe. If a gas like argon were to leak, it would push breathable oxygen out as it filled the room displacing any breathable air. Having no color or odor, a person in the room would be unaware of this exchange of gasses until it was too late. Having an oxygen monitor, like ones sold by PureAire Monitoring Systems, would alert anyone around of a gas leak in time for them to seek safety. If you are interested in using argon gas, contact PureAire Monitoring Systems to learn about how easy it can be to stay safe with an oxygen monitor. Argon has an important place in our modern world, so spread the word and share the knowledge of how to use argon while practicing safety.