Intro to Metal Additive Manufacturing

Why use 3D Printing?

Introduction to 3D Printing ProcessHistorically, metal components have been produced by using manufacturing processes that fall into two categories - subtractive or formative. A manufacturer using a subtractive process, for instance, might mill a part out of a block of raw material. This is a mature and well understood technology but has some limitations in production flexibility, lead times and material waste. 

That same manufacturer might decide to use a formative manufacturing process instead, for instance casting the part from molten metal into a shape close to the desired dimensions. While this method reduces material waste, the drawbacks are that the process requires tooling which can be prohibitively expensive for low volume parts and it has a more limited ability to customize part geometries. 

Now manufacturers have a third process option – additive manufacturing, otherwise known as 3D printing.  These techniques were originally developed in the 1980s and have since progressed from the rapid prototyping of polymers, to the printing of industrial grade metal components such as those currently being validated in the medical, aerospace and tooling industries. 

Additive manufacturing can offer benefits over the more established subtractive or formative processes: 

  • Just-in-Time Production: Many industries keep large warehouses with parts inventories that may never be needed, just in case. With 3D printing, these parts can be made on demand, reducing both the cost of making and maintaining inventory
  • Enhanced Design Flexibility: Additive manufacturing can allow the part designer to create shapes that are impossible or impractical to design through other methods. Additionally by enabling the manufacture of more complex geometries, designers can then combine many parts into one or even build an entire assembly of interconnected and moveable parts in one step
  • Cost: For low volume or customized parts, such as is found in the aerospace or medical industries, 3D printing can be a less expensive production process since no tooling is required and the cost of a single piece of capital equipment can be spread over many parts
  • Sustainability: 3D Printing reduces the ecological footprint of a part by using less material in the part, reducing the risk of creating inventory that is never used and also by allowing parts to be made not just when they are needed but where they are needed – such as on an offshore oil rig, a Navy submarine or even on a space shuttle, reducing transportation impacts


Investments in the development of new 3D printing techniques promise to bring about even more future capabilities, such as the ability to print different material properties into the same part.