Additive Manufacturing of Multi-Material and Composite Parts

Introduction

Manufacturing industries have been faced many difficulties such as manufacturing speed and cost over the years. Therefore, industrialists were focused on alternative manufacturing techniques to increase the manufacturing speed and to control the cost. The restrictions in traditional manufacturing processes have been diminished by the development of different AM processes. The AM process is a rapid manufacturing technology that has the ability to synthesis a component by adding the required composition of material continuously still final part is finished (Boddeti, Ding, Kaijima, Maute, & Dunn, 2018). Commercially, many 3D fabrication techniques are available, comprising electron beam melting, fused deposition modeling (FDM), selective laser sintering and melting, laser engineered net shaping, polyjet 3-D printing, and projection micro-stereo lithography etc. (Spowart, Gupta, & Lehmhus, 2018; Chai et al., 2017; Liu et al., 2017, Stull et al., 2018).

In these methods, metals, plastics, and ceramics are used with a suitable AM process to obtain multi-material products depending on functional requirements (Bandyopadhyay, & Heer, 2018). The development of composite materials by AM can either be achieved during the material deposition process or by a hybrid process. Heterogeneous scaffolds and functionally graded materials (FGM) are fabricated through composite structures which can be obtained various properties in a single integrated component (Toursangsaraki, 2018). The parts can be built with the combination of different materials in the hybrid process of AM. Multi-material AM process is fascinating to the researchers due to its potentials such as customized design and structural applications of rapid manufacturing. It can be achieved the property benefits as similar to the hybridized products. Moreover, the multi-material AM process can be developed the products with fast and robust structures (Ngo, Kashani, Imbalzano, Nguyen, & Hui, 2018; Muguruza et al., 2017).

In conventional manufacturing, the combined materials structures are developed using the joining of mechanical fasteners such as screws or rivets depending on the applications. These kinds of additional setups are not required in a multi-material AM process which can be fabricated multi-material layers or multi-composite parts continuously (Chen, & Zheng, 2018). This technique mainly classified under two categories such as multi-layer method and multi-material structure. In the first technique, the components can be developed layer by layer, where the material of second layer deposits over the first layer material. The second method is called a multi-material structure, where the AM process builds the vertical structure simultaneously using different materials (Edgar, & Tint, 2015).

Figure 1.

Schematic comparison conventional manufacturing and additive manufacturing processes

The multi-material structure is developed using number of steps in conventional manufacturing process. The initial sets of components are fabricated using primary processes where the secondary operations or post processes executed to make the multi-material component. In industry, the basic products are developed using casting, melting and forging process followed by some finishing operation of machining which bring it into desired final product. Thereafter, they allowed to joining processes such as different welding techniques to add the secondary component with that primary part. The difficulties such as time consumption and wastage of materials are observed from the traditional manufacturing processes. In order to avoid such difficulties, additive manufacturing processes are being implemented to prepare a multi-model structure in a single step. The raw powder elements are allowed to make the final multi-parts from the design stage (Bandyopadhyay, & Heer, 2018). A clear illustration of the comparison of conventional and additive manufacturing processes is shown in Figure 1.