There are many situations where parts can’t afford to have any kind of weaknesses or defects. Examples include engine components, medical instruments, and high-strength fasteners. Any kind of failure could be catastrophic. In these cases, titanium forgings are often the best choice. Forging can create ultra-strong, reliable parts that can provide a long service life even in challenging conditions.
Why is forging the best method?
The key thing to keep in mind is how forging works. You begin with a piece of metal and then apply pressure to alter the shape. This could be something as simple as hammering it repeatedly with a tool or forming it with a mould or die.
Significantly, when you forge titanium (and other metals for that matter), you refine the crystalline structure of the material. It becomes more organised and ensures there are fewer cavities. Additionally, it ensures the crystals have a better flow. The end result is the material is stronger and has higher resistance to stress and fatigue.
You can see how beneficial this is if you compare to casting. When you cast products, you need to melt the material and then pour it into a mould. However, it can leave hidden defects like cavities and cracks in the material. The lack of pressure and refinery of the crystalline structure means cast parts won’t be as strong or reliable as titanium forgings.
There are also big advantages if you compare to machining. Machined parts can offer a benefit in terms of the cost. But, again there is no refinement of the crystalline structure of the material. Naturally it means they won’t be as strong. Plus, machining can produce a lot of scrap material.
Methods
An interesting thing to consider is there are actually different methods of forging titanium. This can have a big impact on the final parts.
Typically, in most cases people choose hot forging for titanium. By heating the material, you can make it softer and easier to deform, overcoming the hardness and limited ductility. As a result, it reduces the risk of cracking. If you need ultra-strong titanium forgings, this is the best option.
While it is rarer, there are situations when cold forging is viable for titanium. The key is to use the right equipment and enough force to deform the material. It’s vital to manage this to prevent cracking. Typically you can use this type of forging for small parts.
Looking closer, there are two different techniques; open and closed die forging. The first uses tools to deform the material. Notably, the titanium can move in all directions here. So, it’s a more flexible option, suitable for creating custom parts, including large products.
Closed die forging requires you to use a mould to surround the material. This prevents it from moving freely. However, when you apply pressure, the material will quickly take its final shape. This is a fast, accurate, repeatable option, perfect for batches of products that need to be uniform.
If you are looking to create ultra-strong parts, isothermal forging may be the best method. Here, you ensure the metal and moulds are the same temperature. It provides three noteworthy benefits; it improves deformation, eases stress, and improves the surface finish. While this is a more expensive method, it’s ideal for titanium forgings like engine parts.
What type of titanium to use?
Finally, if you need ultra-strong parts for important applications, it’s vital to choose the right type of titanium. There are lots of options, but not all of them are viable for forging.
By far the most common choice when strength really matters is Ti-6Al-4V (aka Grade 5, an alloy with 6% aluminium and 4% vanadium). It is incredibly strong, lightweight, and has excellent corrosion resistance.
Several beta titanium alloys can be good choices for different needs. Ti-10V-2Fe-3Al was developed for applications where strength is the most important factor. It’s great for hot forging to create airframes and more. Another option is Ti-3Al-8V-6Cr-4Mo-4Zr (aka Grade 19 or Beta C), a high strength alloy perfect for fasteners.
Looking for outstanding titanium forgings?
You can’t afford to compromise on safety and performance when you’re dealing with aerospace, automotive, medical, and various other applications. As a result, ultra-high strength titanium parts are worth the price.
Brindley Metals is happy to assist if you need any help. We supply a wide range of exceptional materials, including many different grades of titanium. This includes materials you can forge effectively. You can contact us to discuss your needs, including various types of titanium forgings. We’ll give you friendly services so you can specify exactly what you need. We even have contacts to provide forging and other services.