Additive manufacturing :-

• Additive manufacturing refers to the set of technologies that allow the manufacture of objects in a sequential manner, usually layer by layer.

• It is the process of adding substances to manufacture or create an object.

• It is defined as additive because the material is added sequentially, as opposed to more traditional (subtractive) manufacturing where material is removed from a solid block until the final part is left.

• Examples of subtractive manufacturing are turning/lathing, CNC or general cutting processes such as laser cutting, water jet cutting, machine cutting, etc.

Advantages of Additive manufacturing :-

• Accelerated prototyping - AM expedites product development by enabling the creation of many varying prototypes that can be produced faster and cheaper in comparison to lengthy traditional methods. Several prototypes can be printed before committing to a production run, leaving less room for error in the whole process. In AM, any changes to the original specification are made digitally, reducing the modification costs to achieve the desired result. Traditional design modifications are generally more expensive to undertake.

• Customisation - AM manufacturing offers design innovation and creative freedom without the cost and time constraints of traditional manufacturing. The ability to easily alter original specifications means that AM offers greater opportunity for businesses to provide customised designs to their clients. With the ease to digitally adjust design, product customisation becomes a simple proposition. Short production runs are then easily tailored to specific needs.

• Energy savings - In conventional manufacturing, machinery and equipment often require auxiliary tools that have greater energy needs. AM uses fewer resources, having less need for ancillary equipment, and thereby reducing manufacturing waste material. AM reduces the number of raw materials needed to manufacture a product. As such, there is lower energy consumption associated with raw material extraction, and AM has fewer energy needs overall.

• Environment benefits - The environmental benefits of additive manufacturing are an advantage to businesses seeking to improve manufacturing sustainability. AM offers many positive environmental benefits in comparison to traditional manufacturing. The most notable of which are waste reduction and energy savings. The processes of additive manufacturing, compared to traditional manufacturing, are more efficient and significantly reduce the environmental impact of waste products. AM offers greater material efficiency because it only uses what is needed to create a product.

• Legacy parts - AM has gifted companies the ability to recreate impossible-to-find, no longer manufactured, legacy parts. For example, the restoration of classic cars has greatly benefited from additive manufacturing technology. Where legacy parts were once difficult and expensive to find, they can now be produced through the scanning and X-ray analysis of original material and parts. In combination with the use of CAD software, this process facilitates fast and easy reverse engineering to create legacy parts.

• Manufacturing and assembly - A significant benefit of additive manufacturing is the ability to combine existing multi-part assemblies into a single part. Instead of creating individual parts and assembling them at a later point, additive manufacturing can combine manufacturing and assembly into a single process. Effectively consolidating manufacture and assembly into one.

• Material waste reduction - In conventional manufacturing processes, material is typically removed from a larger piece of work; think timber milling or cutting shapes from sheets of steel. In contrast AM starts from scratch, adding material to create a component or part. By using only the substance necessary to create that part, AM ensures minimal waste. AM also reduces the need for tooling, therefore limiting the amount of material needed to produce components.

• Part flexibility - Additive manufacturing is appealing to companies that need to create unusual or complex components that are difficult to manufacture using traditional processes. AM enables the design and creation of nearly any geometric form, ones that reduce the weight of an object while still maintaining stability. Part flexibility is another major waste reduction aspect of AM. The ability to develop products on-demand, inherently reduces inventory and other waste.

Disadvantages of Additive manufacturing :-

• Cost of entry - With additive manufacturing, the cost of entry is still prohibitive to many organisations and, in particular, smaller businesses. The capital costs to purchase necessary equipment can be substantial and many manufacturers have already invested significant capital into the plant and equipment for their traditional operations. Making the switch is not necessarily an easy proposition and certainly not an inexpensive one.

• Production costs - Production costs are high. Materials for AM are frequently required in the form of exceptionally fine or small particles that can considerably increase the raw material cost of a project. Additionally, the inferior surface quality often associated with AM means there is an added cost to undertake any surface finishes and the post-processing required to meet quality specifications and standards.

• Additional materials - Currently there is a limit to the types of materials that can be processed within AM specifications and these are typically pre-alloy materials in a base powder. The mechanical properties of a finished product are entirely dependent upon the characteristics of the powder used in the process. All the materials and traits required in an AM component have to be included early in the mix. It is, therefore, impossible to successfully introduce additional materials and properties later in the process.

• It’s slow - As mentioned, additive manufacturing technology has been around since the eighties, yet even in 2021, AM is still considered a niche process. That is largely because AM still has slow build rates and doesn’t provide an efficient way to scale operations to produce a high volume of parts. Depending on the final product sought, additive manufacturing may take up to 3 hours to produce a shape that a traditional process could create in seconds. It is virtually impossible to realise economies of scale.

• Post-processing - A certain level of post-processing is required in additive manufacturing because surface finishes and dimensional accuracy can be of a lower quality compared to other manufacturing methods. The layering and multiple interfaces of additive manufacturing can cause defects in the product, whereby post-processing is needed to rectify any quality issues.

Application of Additive manufacturing :-

1. Aerospace
2. Consumer Products
3. Energy
4. Medical
5. Transportation