What is Mechanical Engineering | Difference Between Additive and Subtractive Manufacturing


Mechanical engineering is a broad concept that involves lots of principles and fields. Manufacturing or production is an essential part to understand it. This article will look into the basic definition of mechanical engineering, the task of mechanical engineers, and the difference between additive and subtractive manufacturing.

What is Mechanical Engineering?

Mechanical engineering can be simply defined as a branch of engineering that involves the design, production and operation of machinery. Mechanical engineering requires an understanding of core areas, such as mechanics, dynamics, and material science. Mechanical engineers use tools such as Computer-Aided Design and product lifecycle management to design and analyze manufacturing plants, industrial equipment and machinery, heating and cooling systems, etc. CNC programming is a method for helping engineers to make the process of manufacturing become automation. The machinery that runs on CNC codes is called CNC machine and performs CNC machining

What Mechanical Engineers Do?

What mechanical engineers do is to take a product from an idea to the marketplace, a broad range of skills are required for completing the process. Mechanical engineers need to acquire the particular knowledge and complex skills, understand the forces and the environment that a product, its parts, or its subsystems will encounter, to design them for functionality, aesthetics, and the ability to withstand the forces and the thermal environment they will be subjected to, and they also need to determine the best way to manufacture them and ensure they will operate without failure.

Additive vs Subtractive Manufacturing - Difference Between Additive and Subtractive Manufacturing

Additive manufacturing and subtractive manufacturing are two different approaches that have evolved for years to fabricate products efficiently and economically. In additive manufacturing, a thin layer of semi-solid material is deposited one over another to build a 3D component, on contrary, layers of materials can also be removed from the solid blank to obtain a product with the desired shape, size and dimension. 

1. In additive manufacturing, layer by layer material is added one over another to develop desired solid 3D products. In subtractive manufacturing, layer by layer material is removed from a solid block to produce the 3D part. 

2. Additive manufacturing is usually suitable for materials having a low melting point, like plastics. Subtractive manufacturing can be applied to all solid materials irrespective of melting point, including plastics, metals and other types. 

3. In additive manufacturing, the volumetric density of the constructive material of the final component can be controlled during operation, in subtractive manufacturing, the density of material can’t be controlled, it will remain the same as that of the initial object. 

4. During the additive manufacturing process, there is no material wastage, but subtractive manufacturing such as CNC milling and turning are associated with material wastage in form of chips, scraps, etc. 

5. When it comes to capability, additive manufacturing techniques like 3D printing can make complex shapes easily, while subtractive manufacturing has limited capability in the fabrication of complex products. In addition, structures containing fully closed internal hollow parts can be produced with additive manufacturing processes, but can’t be realized using subtractive manufacturing, unless applying joining. 

6. The range of materials available is also different. Subtractive manufacturing can work with a broad variety of materials, but additive manufacturing is only applicable to a narrow range of materials. 

7. Subtractive manufacturing processes are more time-efficient and economical, so they are ideal for mass production where there are no tight requirements of product quality, additive manufacturing processes are time-consuming and costly, but provide superior quality and desired properties without any secondary or further processing.