Additive manufacturing is a recent trend in production processes owing to its many benefits. It can be defined as the process of producing parts through the deposition of material in a layer-by-lay...

https://journals.sagepub.com/doi/pdf/10.1177/1687814018822880

Additive manufacturing: Challenges, trends, and applications:

https://digitalcommons.mtu.edu/cgi/viewcontent.cgi?article=3057&context=michigantech-p

Plastic recycling in additive manufacturing: A systematic literature review and opportunities for the circular economy

Additive Manufacturing of Piezoelectric Materials

In the present study Inconel 625 alloy fabricated using Cold Metal Transfer (CMT) Wire Arc Additive Manufacturing (WAAM) has been investigated. The microstructure and mechanical properties of the fabricated Inconel625 alloy, and the influence of torch travel speed on the properties of the manufactured specimens were researched. Microstructural studies revealed variation in microstructure in different layers of the specimen, with the bottom layer consisting of fine primary cellular grains. Mechanical properties that include hardness and tensile properties showed that with the increase in the travel speed, average micro-hardness of the manufactured specimens slightly improved from 248 HV to 253 HV. The ultimate tensile strength (UTS) increased from 647 MPa to 687 MPa, while yield strength (YS) increased from 376 MPa to 400 MPa. Results showed that the mechanical performance of the manufactured components by CMT-WAAM method was better than the mechanical properties of Inconel 625 alloy casting parts except UTS, which demonstrated that the Inconel 625 alloys can be fabricated by cold metal transfer process.

Microstructure and mechanical properties of Inconel 625 fabricated by wire-arc additive manufacturing

Considering the stringent regulations, manufacturing of aircraft parts is often quite complex and time consuming. The multi-million components, multi-tier manufacturing systems and the severe constraints surrounding the sector lead to heavy inventory investments to achieve the just-in-time supply of parts often needed to reduce the airplane ground times. Additive manufacturing evolved allowing for the direct production of complex parts based on digital data with no complex tooling or machinery, a messiah of true just in time production. Appropriate integration of additive manufacturing with the aircraft industry could resolve some of the supply chain and inventory hurdles. Significant progress is already evident in these lines, but the lack of quality assurance attributes and certification standards is hampering the progress. The state-of-the-art of the application of additive manufacturing in the aircraft industry is reviewed in this paper.

https://www.longdom.org/articles/additive-manufacturing-for-the-aircraft-industry-a-review.pdf

Additive Manufacturing for the Aircraft Industry: A Review.

The paper first presents a brief review of development courses of additive manufacturing technology and summarizes the development status and the application fields of additive manufacturing technology, then, according to the manufacturing methods, it focuses on the principles and characteristics of several main additive manufacturing technologies. This paper also analyzes the existing problems and challenges of additive manufacturing technology and its future development trend. This paper aims to provide references for the development direction of additive manufacturing technology in developing countries.

The research status and development trend of additive manufacturing technology

Hydroxyapatite (HA) bioceramics have garnered considerable attention owing to their applications in the field of bone repair and excellent biocompatibility. Compared to extrusion-based 3D printing, projection-based 3D printing (3DPP) can fabricate parts with complex geometry, high accuracy, and efficiency, which is very promising for bioceramic scaffolds. However, conventional 3DPP using a paste with low viscosity will cause severe shrinkage of the parts after sintering, which makes it unsuitable for bioceramic scaffolds, and a system investigation of the printing process remains insufficient. In this study, we proposed a 3DPP device suitable for bioceramic scaffolds and investigated the additive manufacturing of HA scaffolds. Ceramic paste properties and process parameters of curing, debinding, and sintering were initially examined. The mechanical properties, shrinkage, and biocompatibility in vitro of the sintered samples were further investigated. The obtained results indicate that HA bioceramics with uniform morphology, complex structure, and high accuracy can be manufactured using the 3DPP equipment. HA scaffolds have the mechanical strength of human cancellous bone, while HA scaffolds cultured with osteoblast precursor cells possess strong biocompatibility and can promote osteoblast adhesion, proliferation, and differentiation. These results suggest a promising application of the 3DPP technique in the preparation of bioceramic scaffolds, and the HA scaffolds fabricated using the 3DPP technique exhibit promising potential in fulfilling a constructive role in the biomedical field of human bone regeneration repair. 

Yong He

Papers

The research status and development trend of additive manufacturing technology

Additive Manufacturing of Hydroxyapatite Bioceramic Scaffolds with Projection Based 3D Printing