Hybrid Processes in Additive Manufacturing

Abstract

Hybrid additive manufacturing (hybrid-AM) has described hybrid processes and machines as well as multimaterial, multistructural, and multifunctional printing. The capabilities afforded by hybrid-AM are rewriting the design rules for materials and adding a new dimension in the design for additive manufacturing (AM) paradigm. This work primarily focuses on defining hybrid-AM in relation to hybrid manufacturing (HM) and classifying hybrid-AM processes. Hybrid-AM machines, materials, structures, and function are also discussed. Hybrid-AM processes are defined as the use of AM with one or more secondary processes or energy sources that are fully coupled and synergistically affect part quality, functionality, and/or process performance. Historically, defining HM processes centered on process improvement rather than improvements to part quality or performance; however, the primary goal for the majority of hybrid-AM processes is to improve part quality and part performance rather than improve processing. Hybrid-AM processes are typically a cyclic process chain and are distinguished from postprocessing operations that do not meet the fully coupled criterion. Secondary processes and energy sources include subtractive and transformative manufacturing technologies, such as machining, remelting, peening, rolling, and friction stir processing (FSP). As interest in hybrid-AM grows, new economic and sustainability tools are needed as well as sensing technologies that better facilitate hybrid processing. Hybrid-AM has ushered in the next evolutionary step in AM and has the potential to profoundly change the way goods are manufactured.

The Potential of Additive Manufacturing in the Smart Factory Industrial 4.0: A Review

“…These processes can take place either concurrently or in sequence to complete the required task from the machines and there is no limitation on the number of processes utilized in order to produce the 3D object. The goal of hybrid manufacturing is to get the input materials and change them to the final product in one machine or workstation [84]. On the same page, the goal of the hybrid manufacturing processes is to utilize AM processes as the primary step of the manufacturing and use the benefits of the other assistive processes to get the highest accuracy [85].…”

Hybrid manufacturing of titanium Ti-6Al-4V combining laser metal deposition and cryogenic milling

“…Two milling strategies were followed in this study, namely, milling of the side surfaces and the top surfaces of the additively manufactured parts. Depending on the application, both strategies could be relevant in practice, whereby the former is primarily used to adjust the surface quality of component areas that will later no longer be accessible, while the latter serves to ensure a suitable substrate surface for the LMD process [32]. In both cases, cryogenic machining could be a suitable alternative to conventional machining concepts.…”

“…Moreover, intermediate machining steps are often required for functional integration [29] or multi-material applications [30], which are associated so far with intermediate cleaning [31]. Milling of the side surfaces enhances the surface quality of the final component, whereas milling of the top surfaces helps to ensure continuous increase in height while providing a reproducible surface condition for the subsequent material deposition, respectively [32]. A further important aspect lies in the field of quality control and assurance where a defined number of layers with exactly defined surface conditions can be examined and evaluated to detect defects at an early stage and repair them immediately.…”

Ultrasonic Peening Treatment Used to Improve Stress Corrosion Resistance of AlSi10Mg Components Fabricated Using Selective Laser Melting

“…At present, some approaches including optimization of processing strategy and parameters, substrate preheating, post-heat treatment, and hybrid post process are usually used to control the distribution and magnitude of the internal stress field of the laser additive manufacturing components, thereby improving the comprehensive performance of the components [6][7][8]. All the 2 of 8 processing parameters, such as scanning speed, scanning strategy, laser power, and thickness, will affect the thermal stress distribution in the component.…”

“…Kreitcberg et al [16] explored the effect of post-heat treatment on mechanical properties and microstructures of Inconel 625 alloy parts built using SLM. Processes including shot peening, rolling, laser shock peening, and UPT are also used to modify the residual stress distribution of parts during or after the AM process [7,[17][18][19]. UPT has the advantages of small size, strong controllability, and flexible application.…”