Announcements

We are delighted to invite the winner of the Coatings 2024 Best Paper Award, Dr. Rodolpho Vaz, to discuss the review paper “A Review of Advances in Cold Spray Additive Manufacturing”. The paper was published in Coatings (ISSN: 2079-6412) and discussed the examination of the advancements in Cold Spray Additive Manufacturing (CSAM) over the past decade. We hope you enjoy the interview below:

1. Could you please briefly introduce yourself to our readers? Could you share your current research focus and the latest developments in your work?
My name is Rodolpho Fernando Váz, PhD in engineering and applied sciences from the Universitat de Barcelona (Spain), MSc in mechanical engineering from the Universidade Federal do Paraná (Brazil), and BSc in mechanical engineering from the same institution. Over the past 20 years, I have dedicated my career to the development, characterization, and application of wear-resistant coatings, particularly cermets and Fe-based systems. My work has primarily focused on thermal spraying processes, especially arc spraying and high-velocity oxy-fuel (HVOF).

In the last six years, I have also concentrated on advancing Cold Spray as an Additive Manufacturing technique by developing new robotic strategies for building complex geometries and by applying various post-treatments to improve the mechanical properties of fabricated parts, particularly cohesion and strength.

I am currently a researcher at the Center for Thermal Spraying Research (CTSR) at Stony Brook University (United States). My present research focuses on understanding and mapping the cross-effects of HVOF processing parameters, coating stress evolution, and binder composition on the wear performance of WC–Co cermets for severe wear applications.

To date, I have published 33 peer-reviewed papers, delivered 37 conference presentations, and accumulated 486 citations (h-index: 13). In addition, I am the co-inventor on 1 patent, have participated in 17 R&D projects (as researcher, project manager, or principal investigator), and completed over 260 peer reviews of scientific papers, among other academic and professional activities.

2. Could you provide a brief overview of the main content of your award-winning paper?
When I began researching cold spray, I observed that many researchers and institutions were exploring diverse approaches to characterize the deposits, developing strategies for part fabrication, and enhancing the mechanical properties of materials, such as strength. In this context, we—the co-authors—compiled the most relevant and novel findings from the last decade, which resulted in a review article published in Coatings. This work summarizes and discusses the most influential parameters of the cold spray process, including processing parameters (gas temperature and pressure, which determine particle velocity); robotic movement strategies to improve deposit density and geometric accuracy; feedstock material selection (e.g., spherical vs. irregular powders, or small vs. large particle sizes); and post-treatment techniques such as heat treatments and hot isostatic pressing.

Beyond summarizing the results and conclusions reported in high-impact journals by leading scholars in the CSAM field, the article also addresses existing controversies and highlights current knowledge gaps. These aspects must still be resolved to reliably predict and control the capabilities of Cold Spray Additive Manufacturing (CSAM) for producing high-performance components and to support the consolidation of this technique in industrial applications.

3. What do you think are the key elements for writing a successful review paper? Could you describe some challenges and breakthroughs in your research field?

I see the very first step as reading as many papers as possible, without being limited to researchers who share the same opinions and concepts as mine. Beyond focusing only on my research theme, exploring other coating techniques and materials—whether directly related or not—can broaden my background and create bridges between previously unconnected subjects. When reading, it is essential to maintain a critical perspective by asking “Do the authors’ arguments make sense? What is missing from this work? How could it be complemented? Are there other studies that address these gaps?”. These questions are fundamental when preparing a review-type paper. Compiling the work of other authors, merging their ideas with constructive criticism, and proposing trends and future directions to fill existing gaps is one of the greatest challenges for review paper writers.

4. How does it feel to receive the Best Paper Award? What does this recognition mean to you?

It was a great honor to receive this recognition from Coatings. Writing an impactful paper was a challenging task, and this achievement would not have been possible without the invaluable contributions of my colleagues and the reviewers, who helped shape the first draft and significantly improve the manuscript during the review process. Their support made the work much stronger.

Beyond the award itself, it is deeply rewarding to see that this paper has been useful to many researchers, as reflected by the more than sixty citations it has already received. Such scholarly recognition, combined with the distinction of receiving an award from a prestigious journal like Coatings, provides strong motivation to continue advancing knowledge and contributing to society through the publication of high-quality research.

5. In your opinion, which research topics do you think will be the most popular in the field of coatings and cold spray technology in the coming years?

I have observed that the development of hybrid deposition systems has become a prominent research trend. Examples include atmospheric plasma combined with arc spraying to produce harder and denser wear-resistant coatings, or laser-assisted cold spraying to enhance particle cohesion. The concept of hybrid systems opens the door to countless possibilities, with synergies that remain largely unexplored by “merging” the advantages of two or more fundamentally different deposition techniques.

In addition to advances in processing, the development of new materials also continues to be a major trend. High- and medium-entropy alloys, for instance, offer exciting opportunities. Research on in situ HEA formation during deposition could significantly reduce the time and cost associated with producing specialized powders, while yielding coatings with exceptional corrosion and wear resistance.

6. What attracted you to submit your work to Coatings? Could you share your experience of submitting to this journal?

Regarding my choice of Coatings, firstly, it is a journal dedicated to my research topics, and my work fits perfectly within its scope. Secondly, the submission, review, proofreading, and publishing process in Coatings—and MDPI journals in general—is much faster than in many other leading journals, which aligns with my sense of urgency to make my work visible and accessible. Thirdly, Coatings has a growing reputation and impact factor, both of which are important for my academic profile and career development. Finally, and no less importantly, Coatings has consistently published high-quality works with clear scientific contributions in thermal spraying processes and cold spray additive manufacturing, which have been the core of my research for decades. For these reasons, I plan to continue publishing many more works in Coatings.

7. What advice and insights would you share with young scholars, particularly when it comes to selecting research topics and maintaining persistence?

Young scholars—almost all of them—need to cultivate greater patience and humility. Advisors, colleagues, professors, lab technicians, students, and everyone in academia have something valuable to contribute to improving the quality of our work. Whether it is a tip, a criticism, or assistance in interpreting test results, it is always important to listen carefully and avoid arrogance.

This attitude also applies to the feedback we receive from peer reviewers when submitting a manuscript to a journal. I prefer to view their comments not as “criticisms,” but rather as “recommendations” aimed at strengthening our work. We must approach these remarks as opportunities to enhance the quality of our research, not as an underestimation of our effort.

In summary, the entire scientific community shares the same goal: to bring out the best in our work for the advancement of science.

8. As the recipient of this award, could you share your feelings and whom you would like to thank?

I would like to thank my colleagues who contributed to the development of this work and assisted in writing the first draft of the manuscript: Andrea Garfias, Vicente Albaladejo, Javier Sánchez, and Irene García Cano from the Thermal Spray Center (CPT) at the Universitat de Barcelona. I am also grateful to the four anonymous reviewers for their valuable recommendations and suggestions, which significantly improved the quality of the manuscript, as well as to the editors of the Advanced Cold Spraying Technology Special Issue—Wen Sun, Xin Chu, and Adrian Wei Lee Tan—for their support.

9. What are your views and expectations regarding the open access model of publishing?

I believe that free access to high-quality scientific papers greatly facilitates the diffusion of knowledge, benefiting both scholars and society at large. Open access allows anyone to read the most recent advances in science without financial barriers. Naturally, the costs of publication must still be covered, and in the open access model, this responsibility falls on the authors, who often rely on university support or project funding to cover publication fees. Despite this challenge, I see open access as the most effective way to publish scientific research and disseminate knowledge broadly. Long live open access!