Titanium powder is used in additive manufacturing and numerous other areas in the powder metallurgy sector. However, this fine metal powder is not entirely harmless. In this article, we will be pointing out which challenges may arise and how to deal with them.
Titanium powder: Metal powder with special properties
Titanium powder is one of the most popular metal powders in a multitude of different areas. Due to high tolerability levels, for example, this is a material which is frequently used for implants designed for the human body. Titanium and titanium alloys, however, are also often used for jewellery and in the aerospace industry. After all, this particular metal excels through its low density and, accordingly, through minimal weight. Nonetheless, when processing titanium powder, a certain amount of care needs to be taken.
General hazards connected with powder metallurgy processing
When working with metal powders in general, the lungs and mucous membranes of those concerned are particularly at risk. Inhalation of metal dust can cause mild to severe health problems, depending on the element in question. In addition to these typical challenges which are encountered when working with metal powder and can normally be easily resolved through the use of appropriate protective equipment, there is yet another danger connected with titanium powder.
Titanium powder: Highly reactive and hazardous
In a compact form, titanium is totally harmless – in powder form, however, there is a high risk of combustion. Light metal powders, such as titanium as well as magnesium and aluminium, for example – are highly flammable – and even liable to spontaneous combustion. This flammability depends on factors such as the grit size. The general rule of thumb is: The finer the distribution of the titanium powder, the greater the risk.
If titanium dust is disturbed, it can react with the air in the room even at room temperature. Ultimately, the heat resulting from this reaction leads to spontaneous combustion. Powder residues that have settled on work clothing may even cause the clothing to catch fire. Sometimes a single spark, for example from a grinding machine, might be enough to trigger such a reaction.
Tips for handling titanium powder correctly
The risks that emanate from titanium powder, however, are no reason to forego using this high-performance material. If you create the right basis for dealing with titanium powder, you can minimise the risks and reap the benefits.
Tip 1: Safe storage
It is absolutely vital to store titanium powder in tightly closed containers and keep it away from sources of heat and ignition. Normally, the recommended storage temperature can be found in the manufacturer’s specifications. Both these containers as well as the equipment to be filled must be accordingly earthed. The storage location itself should be dry and well-ventilated and comply with the legal requirements pertaining to safe storage facilities for flammable hazardous substances.
Tip 2: Practised handling methods
To ensure that titanium powder is handled safely, there are several precautions that should – and must – be taken at the point of processing. The room should be well-ventilated, with explosion-proof lighting and ventilation systems. Handling the powder in inert gas conditions minimises contact with the air.
It is crucial for anyone working with titanium powder to wear appropriate protective clothing. This includes safety goggles, gloves, flame-retardant protective clothing to protect the body and respiratory equipment. Contaminated clothing should be changed prior to switching workplaces, at finishing time and before a break to prevent clothes from catching fire as described above.
Tip 3: Preparation for an emergency
Should there be a light metal fire involving titanium powder despite all the precautions, on no account should this be extinguished using water. This is because light metals react strongly with water. The resulting hydrogen is likewise highly flammable – causing an explosion in the worst-case scenario. This also means that water-based fire extinguishing agents, such as foam, are unsuitable for extinguishing titanium fires. That is why special extinguishing agents or equipment must be available at the processing and storage sites. Extinguishing agents include, for example, metal fire powder, dry sand and noble gases, such as argon.
When it comes to safety, you should not cut corners when handling titanium powder
If you work with titanium powder, it is imperative to comply with the respective laws and regulations in order to protect the lives of your employees. The following regulations are amongst those which should be consulted to provide a basis to work on:
- German Ordinance on Hazardous Substances
- German Ordinance on Industrial Safety and Health
- TRGS 800: German Technical Rules for Hazardous Substances: “Fire protection measures”
- DGUV-R 113-001: German Social Accident Insurance regulations: “Explosion protection regulations”
Prior to usage, you should familiarize yourself thoroughly with the regulations. If the currently applicable regulations are observed, the risk of spontaneous combustion or other accidents involving titanium powder can be minimised to the greatest possible degree. Despite the higher amount of effort required in comparison with less dangerous metal powders, it pays off in the long run thanks to the special properties found in titanium.