A wide variety of coating methods and materials are available for different coating applications with a common purpose of protecting a part or structure exposed to mechanical or chemical damage. A benefit of this protective function is to decrease manufacturing cost since fabrication of new parts is not needed. Available coating materials include hard and stiff metallic alloys, ceramics, bio-glasses, polymers, and engineered plastic materials, giving designers a variety freedom of choices for durable protection. To date, numerous processes such as physical/chemical vapor deposition, micro-arc oxidation, sol–gel, thermal spraying, and electrodeposition processes have been introduced and investigated. Although each of these processes provides advantages, there are always drawbacks limiting their application. However, there are many solutions to overcome deficiencies of coating techniques by using the benefits of each process in a multi-method coating. In this article, these coating methods are categorized, and compared. By developing more advanced coating techniques and materials it is possible to enhance the qualities of protection in the future.

On Coating Techniques for Surface Protection: A Review

Additive manufacturing (AM) or three-dimensional (3D) printing has introduced a novel production method in design, manufacturing, and distribution to end-users. This technology has provided great freedom in design for creating complex components, highly customizable products, and efficient waste minimization. The last industrial revolution, namely industry 4.0, employs the integration of smart manufacturing systems and developed information technologies. Accordingly, AM plays a principal role in industry 4.0 thanks to numerous benefits, such as time and material saving, rapid prototyping, high efficiency, and decentralized production methods. This review paper is to organize a comprehensive study on AM technology and present the latest achievements and industrial applications. Besides that, this paper investigates the sustainability dimensions of the AM process and the added values in economic, social, and environment sections. Finally, the paper concludes by pointing out the future trend of AM in technology, applications, and materials aspects that have the potential to come up with new ideas for the future of AM explorations.

/pdf/the-potential-of-additive-manufacturing-in-the-smart-factory-5gfoxv04tc.pdf

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

Abstract Carbon nanotube reinforced alumina matrix nanocomposite was fabricated by sol–gel process and followed by spark plasma sintering process. Homogeneous distribution of carbon nanotubes within alumina matrix can be obtained by mixing the carbon nanotubes with alumina sol and followed by condensation into gel. The mixed gel, consisting of alumina and carbon nanotubes, was dried and calcinated into carbon nanotube/alumina composite powders. The composite powders were spark plasma sintered into carbon nanotube reinforced alumina matrix nanocomposite. The hardness of carbon nanotube reinforced alumina matrix nanocomposite was enhanced due to an enhanced load sharing of homogeneously distributed carbon nanotubes. At the same time, the fracture toughness of carbon nanotube reinforced alumina matrix nanocomposite was enhanced due to a bridging effect of carbon nanotubes during crack propagation.

Fabrication of Carbon Nanotube Reinforced Alumina Matrix Nanocomposite by Sol-gel Process

Smart manufacturing is the technology utilizing the interconnected machines and tools for improving manufacturing performance and optimizing the energy and workforce required by the implementation of bigdata processing, artificial intelligence and advanced robotics technology and interconnectivity of them. This paper defines and discusses the smart manufacturing system and states it current implementation status and analyzes the gap between current manufacturing system and the predicted future smart manufacturing system, discusses the technologies associated with it and their contribution in smart manufacturing technology. Also, to realize this rapidly growing technology and cover its all dimensions a survey of the latest developments in this field and its impacts were analyzed and presented along with the challenges of implementation, opportunities and the future directions for smart manufacturing system.

Challenges, Opportunities and Future Directions of Smart Manufacturing: A State of Art Review

Selective laser melting of Ti6Al4V alloy: Process parameters, defects and post-treatments

To facilitate patient healing in injuries and bone fractures, metallic implants have been in use for a long time. As metallic biomaterials have offered desirable mechanical strength higher than the stiffness of human bone, they have maintained their place. However, in many case studies, it has been observed that these metallic biomaterials undergo a series of corrosion reactions in human body fluid. The products of these reactions are released metallic ions, which are toxic in high dosages. On the other hand, as these metallic implants have different material structures and compositions than that of human bone, the process of healing takes a longer time and bone/implant interface forms slower. To resolve this issue, researchers have proposed depositing coatings, such as hydroxyapatite (HA), polycaprolactone (PCL), metallic oxides (e.g., TiO2, Al2O3), etc., on implant substrates in order to enhance bone/implant interaction while covering the substrate from corrosion. Due to many useful HA characteristics, the outcome of various studies has proved that after coating with HA, the implants enjoy enhanced corrosion resistance and less metallic ion release while the bone ingrowth has been increased. As a result, a significant reduction in patient healing time with less loss of mechanical strength of implants has been achieved. Some of the most reliable coating processes for biomaterials, to date, capable of depositing HA on implant substrate are known as sol-gel, high-velocity oxy-fuel-based deposition, plasma spraying, and electrochemical coatings. In this article, all these coating methods are categorized and investigated, and a comparative study of these techniques is presented.

https://www.mdpi.com/1996-1944/12/11/1795/pdf

Coating Techniques for Functional Enhancement of Metal Implants for Bone Replacement: A Review

https://iopscience.iop.org/article/10.1088/2053-1591/aae10e/pdf

Fatigue performance of selective laser melted Ti6Al4V components: state of the art

Published by Nature Research Society http://nrs.org Proceedings of the Nature Research Society, 2, 02008 (2018) | 1 Sol-gel process applications: A mini-review Amir Dehghanghadikolaei,* Jamal Ansary, Reza Ghoreishi 1 Mechanical, Manufacturing and Industrial Engineering Department, Oregon State University, Corvallis, Oregon 97331, USA 2 Mechanical, Manufacturing and Industrial Engineering Department, The University of Toledo, Toledo, Ohio 43606, USA 3 Mechanical Engineering Department, Semnan University, Semnan, Iran *Corresponding Author. Email: Amir.Dehghanghadikolaei@rockets.utoledo.edu

Amir Dehghanghadikolaei

Papers

On Coating Techniques for Surface Protection: A Review

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

Coating Techniques for Functional Enhancement of Metal Implants for Bone Replacement: A Review

Fatigue performance of selective laser melted Ti6Al4V components: state of the art

Sol-gel process applications: A mini-review