The aerospace and defense industry is leading the way in an exciting shift and step in the industrialization of additive manufacturing (AM) technology. The industry leaders historically responsible for driving the use and adoption of AM continue to make large investments in facilities, machines, technology and workforce to support their implementation strategies. The talk of the past has been around challenges and requirements to get “a” part into production and flight, and now companies like Honeywell, United Technologies and GE are talking about initiatives to increase the number of parts in production with ambitious goals. Industry is seeing a shift from “how” to “how many more”, and that is very exciting for AM.
The focus on increasing adoption and number of parts in production reaffirms the importance and inherent desire to make parts faster and to make larger parts, the former being an important piece of enabling the later. Increasing the productivity can be done by several approaches, three of the most valuable being the thickness of each layer in the build, the power of each laser and the number of lasers.
The thicker the layers, the fewer number of layers needed to build the part, and therefore, the faster the part is built. In order to enable thicker layers higher laser power is needed to provide enough energy to melt the larger amount of powder in the thicker layer, increasing the laser power can also enable faster laser scan speeds and higher build rates.
The benefits of increasing the layer thickness and laser power are directly multiplied when the number of lasers in the machine is increased. When all these approaches are leveraged together, significant improvements in productivity are realized.
SLM Solutions is, in part, focused on products of these key enablers of increased productivity. Our latest products demonstrate the full-scale approach to increased productivity utilizing from 1 up to 4 lasers with laser power to 700 W, resulting in systems capable of building both aluminum and titanium alloys using 90 micrometer-layer thicknesses.
The value of the increased productivity can be seen in the following graphic, where the titanium part realized 80% more part volume built in the same time through utilization of high-productivity build parameters:
While increasing build rate is a priority, we must be mindful that application requirements will remain unchanged. Development and control of the process parameters is a critical aspect of increasing productivity. As the laser interacts with larger volumes of powder in thicker layers and more heat is being input to the melting and solidification of material with higher laser powers and laser scan speeds are increases, there are many opportunities for material defects to arise. Increasing the productivity of AM cannot come at the expense of material quality. Careful control of the process parameters is paramount to maintaining material properties and performance, especially for the part and application requirements of the A&D industries.
The pressure to make parts faster while maintaining material quality will persist, and AM technologies will continue to improve and demonstrate these priorities as industry adoption grows. Providing a solution to the challenge of increasing build rate through increasing layer thickness, laser power and the number of lasers has proven highly valuable. Further development of these technical aspects will continue to drive increasing productivity in metal additive manufacturing to help set new goals for “how many more” parts will be ready for manufacturing and production.