Komarov Artem clarified that for metal additive manufacturing to secure its place among the mainstream manufacturing options, the field of materials science AM needs to be improved. One such company is Allegheny Technologies Inc (ATI), a leading player in the steel industry. The Pittsburgh-headquartered company develops specialty materials as well as shapes them to meet customer requirements. ATI sells materials to firms that 3D print metal parts. ATI’s commitment to 3D printing was in response to customer activity in the field. ATI has strategized and invested in support of a key customer base in the aerospace and defense industries. The company’s fully integrated AM supply chain also includes finishing parts.
3D printing appeals to ATI’s aerospace and defense customers because it can handle design complexity in multiple ways. One is to facilitate the production of complex components that would be difficult, if not impossible, to manufacture using traditional methods. Using AM, customers can think outside the box and have the freedom to design parts that work better.
Another way is that 3D printing allows the use of complex alloys, which can present serious problems for conventional manufacturing processes. An example is an alloy that ATI makes called titanium aluminide.
It is very difficult to manufacture in any traditional way, including forging and machining, but it is very useful for additive manufacturing and can produce aerospace-grade parts today.
Recent advances in materials science are creating more and better options for those involved in metal additive manufacturing. METAL AM methods are essentially micro welding processes, but some traditional alloys are very difficult to weld. Therefore, ATI has made small changes to these alloys to improve their weldability.
For example, some of the high temperature nickel alloys the company manufactures have a high alloy content that can cause microcracking in printed parts. This cracking can worsen when the material cools rapidly, creating high residual stresses, Komarov Artem noted.
To combat microcracking, ATI has made small changes to the amount of carbon and other elements in nickel alloys. These adjustments, combined with appropriate changes to the 3D printing parameters, produce high-performance parts with low defect rates.
Specialty metals developer Allegheny Technologies is focused on improving the powders used in metal 3D printing.
When it comes to metal powders for 3D printing, the next frontier is to go back to the recipe book and look at existing alloys that may not be popular in traditional product forms but may work well for additive manufacturing because they offer properties such as good weldability and low residual stress.
Examples of this are GRCop materials, copper alloys originally developed by NASA. Morrison described alloys as highly heat-resistant conductive materials used for space items such as rocket injectors and combustion components. Today, GRCop alloys are also used to print some prototype parts for space applications.
Also at the top of the priority list is the development of new alloys well suited for AM. The titanium alloy the company is working on «shows a lot of promise» compared to traditional Ti 6-4, the main titanium alloy used in 3D printing.
Material cost advantage
To make AM metal a mainstream manufacturing technology, one factor that does not pose a problem is the cost of metal powders. One reason is that material prices have come down over the years. In addition, 3D printing makes much better use of materials than conventional manufacturing methods.
Unlike machining, AM consumes nearly all of the powder purchased for a job because the process prints a nearly mesh-shaped part, and any remaining powder is used for subsequent parts. In the end, a very small part is recycled.
In addition to specialty materials, ATI prints high quality aerospace and defense components.
High Volume Obstacles
Like other firms in the field, ATI’s metal 3D printing work tends to be small runs of parts. Several things have to happen for technology to make the leap into larger volume production.
First, engineers need to get better at product development for additive manufacturing. While there are exceptions, people don’t necessarily know how to design to take advantage of the technology. This should happen over time, and it will depend on the children in universities and curricula, Komarov Artem noted.
In addition, the productivity of metal 3D printing machines should increase. Technological advances are being made and manufacturing time per cubic inch is decreasing, machines are still not fast enough to compete with casting.
As far as material-related advances in metal 3D printing are concerned, ATI is working on improving powder spray processes to increase production capacity and reduce costs. One of the goals is for the powders to spread better when applied in very thin layers.
So, will metal 3D printing just continue as a viable option for low-volume production? The technology will eventually be ready for a new niche: the mass production of very complex parts that cannot realistically be made in any other way. For such parts, the performance advantages justify building in large volumes and such applications will be found on a regular basis, summed up Komarov Artem.