Have you seen 3D Printing in-action, yet? If not, today is your lucky day…
The emergence of 3D Printing technology – also known as Additive Manufacturing – is challenging the way many products have been traditionally made.
The process that may be potentially most impacted by 3D Printing is machining, referred to as subtractive manufacturing. Subtractive manufacturing is a well-established method to produce consistent products by removing excess material. Additive manufacturing is the process of creating a product by using various methods to bind layers of material together.
Now let’s compare these two process by their advantages and disadvantages:
Additive manufacturing is similar to building something out of Lego. You create a 3D model of your product, then layers of materials are added on top of each other – the Lego bricks, in this metaphor. Finally, these layers are joined together to create the finished product. Additive manufacturing typically is done with plastic material however, with the recent advances in this technology, metal and ceramic parts are becoming ever more common.
Unlike subtractive manufacturing, 3D printing allows you to produce incredibly complex products. Better yet, it can produce these products quickly, with minimal lead times, which makes additive manufacturing the ideal method for developing prototypes or low volume / custom products. The higher the part complexity, the greater advantage 3D printing has over conventional methods such as subtractive manufacturing. In addition, 3D printing efficiently uses nearly 100% of the raw material, leading to minimal, if not zero waste.
While additive manufacturing is catching up to subtractive manufacturing in a lot of ways, it still remains best suited for smaller batches of product. When it comes to scale, subtractive manufacturing is both more efficient, and less expensive. Additionally, at the current state of the 3D printing technology, final parts may have internal voids and can exhibit anisotropic behavior, while machining form wrought or forged materials will be more homogeneous with predictable quality [I. Gibson et al., Additive Manufacturing Technologies,2010].
Think of subtractive manufacturing as though you were carving a figure from a block of wood. You start with your material, then using an assortment of tools, you whittle down the material, layer by layer, until you end up with your finished model. Essentially, you subtract the material you don’t want from the material you do want, until you’re left with your product.
Unlike additive manufacturing, which typically uses plastic (though that is changing), subtractive manufacturing can be used to make products out of wood, metals, stone and ceramics. On a larger scale, subtractive manufacturing may also be less expensive than additive manufacturing.
Though it may be less expensive, subtractive manufacturing is also less efficient when producing complex parts, and lacks the key ability to create hollow sections within a product. Subtractive manufacturing also requires a great deal of set up and programming precision, leading to longer lead times than 3D printing. In addition, subtractive manufacturing results in significantly more wasted material.
Additive Manufacturing vs. Subtractive Manufacturing
A rough comparison of the competitiveness between the two manufacturing methods is shown in the figure below in terms of the complexity, detail capability, size range, materials capability, near net shape, and lead time.
While the graph clearly indicates traditional machining (subtractive manufacturing) reigns in the majority of cases, we’re drawn by the unique attributes offered by the additive manufacturing process.
Which strikes us with the question: why choose?
What if we could reap the benefits of both processes, by joining two and two together? Imagine the possibilities that could result from having the best of both worlds…
Let’s Remember, This Is Just the Beginning
3D printing is still a relatively new technology.
As such, it lags behind subtractive manufacturing in a few key areas. The good news? As the technology develops and new techniques and equipment are created, additive manufacturing may become as significant in manufacturing as subtractive manufacturing.
Does the whole “3D Printing Process” catch your eye? Ours too! In fact, at Kennametal, we have a unique group of experts exploring what this new and exciting technology can do for the manufacturing industry.
Learn about their journey HERE.
In this ever-changing world of modern technology, stay ahead of the game by keeping up-to-date with our 3D Printing Series! Did you miss our first article, highlighting the history of where thisl started? No problem, you can find it HERE.