The role of lasers in additive manufacturing (AM)

Additive manufacturing

No one can deny that lasers significantly influence fields as diverse as telecommunications, instrumentation, medicine, computing, and entertainment. Their applications include cutting, drilling, welding, bending, cladding, cleaning, marking, and heat treatment in manufacturing.

Lasers are being used on a broader scale, with higher powers allowing for larger-scale work and higher beam qualities and shorter pulse widths allowing for smaller-scale work. In terms of revenue, the global laser market is expected to reach $9.7–11.7 billion in 2015 and $16.0 billion in 2022.

One application has been singled out as a potential game-changer that could usher in a new industrial revolution. On the other hand, revolutionary technology is likely to restructure supply chains, relocate production facilities, and drastically alter the geopolitical, economic, social, demographic, environmental, and security landscapes. This is an additive manufacturing process (AM).

Additive manufacturing (AM) began as a rapid prototyping technology for creating haptic models and has evolved into what it is today: a rapid tooling and manufacturing technology capable of producing fully functional parts in various materials, including metallic, non-metallic, and composites.

Additive manufacturing is a topic that continues to pique people’s interest, with predictions that it will significantly impact the industry in the future. According to ASTM Standard F2792, additive manufacturing processes are classified into seven categories: binder jetting, directed energy deposition, material jetting, material extrusion, powder bed fusion, sheet lamination, and vat photopolymerization. The operation of various AM systems has relative benefits and drawbacks. Although lasers do not have a monopoly on AM, it is clear from the classification that three of the seven major categories and two of the three process categories capable of producing metallic components require lasers.

Because of the evolution of AM systems into user-friendly, commercial units and the need for safety, the presence of a laser is not always prominent. Furthermore, to protect the build point from harmful oxidation during AM of metals, the user must be removed from the ‘sharp end’ of the manufacturing process, either by performing the entire operation in an inert chamber or by using a blown inert gas.

Existing commercial AM systems clearly make use of a variety of laser technologies. Wavelengths from the ultraviolet (354.7 nm) to the infrared range from around 1 W to 6 kW. (10.6 um). The requirements differ from one process to the next. However, the need to match SLA lasers to the polymer absorption spectrum, the use of different lasers for different materials in the powder bed fusion bed category, and the use of the shorter wavelength diode laser for directed energy deposition (DMD), despite poorer beam quality than the fiber laser, all indicate that absorption is a significant factor in laser selection.

AM is expected to snowball because it broadens design engineers’ horizons by providing a fundamentally different approach to traditional subtractive methods. This can also allow a broader range of components to be made as a single part, reducing the amount of material needed and eliminating the need for any type of joining. High costs, on the other hand, can negate these advantages.

The role of lasers in the future of AM

In the medium term, the significant users of additive manufacturing are unlikely to significantly change consumer products, direct medical components, transportation (including automobile and aerospace), and tool and mold manufacturing. The prediction that AM will change the way companies interact and global supply chains operate on a global scale will not be accurate unless a broader range of industries can be incentivized to use AM in the future.

To be successful, a company’s organization and culture must adapt from traditional to additive manufacturing, and research indicates that AM is having difficulty penetrating high-threat markets with fierce competition. Potential barriers include resource rigidity (failure to change resource investment patterns) and routine rigidity (failure to change organizational processes that use those resources). AM can address primary industry goals and trends, and the majority of these processes are laser-based.

As many predict, AM will need to break into new industries to continue to grow and become the dominant technology. Although some factors may apply to other sectors, the above analysis does not provide many incentives. (For example, in all markets, ‘accelerated product development’ is becoming more critical, and ‘aging population’ is likely to have an impact on demand for many products.)