# State of the Art in Metal Matrix Composites Research: A Bibliometric Analysis
## 6 Conclusions
The third highest number of MMC articles (2703, 26.98%) were categorized under the general research direction of 'engineering', dealing with the various engineering aspects of MMCs. These three research directions witnessed steadily increasing publication trends during 2001-2020. * 6. There is a lot of scope in the MMC research directions pertaining to 'automation control systems','mining mineral processing' and 'optics'. * 7. Researchers affiliated with the USA published the most MMC articles during 2001-2004 (60 papers in 2004). From 2005 to 2012, Chinese authors published the maximum number of WoS papers (114 papers in 2012). Post 2012, Indian investigators contributed maximum articles in WoS (415 papers in 2020). * 8. Globally, the Harbin Institute of Technology, China published the maximum number of WOS papers (335, 3.34%) in the field of metal matrix composites. The Shanghai Jiao Tong University, China (271 papers, 2.71%) and the Chinese Academy of Sciences (227 papers, 2.27%) contributed the second and third highest number of MMC articles in WoS. * 9. Among Indian organizations, the Indian Institutes of Technology published the maximum articles (225) followed by National Institutes of Technology (156 papers) and Anna University (113 papers). * 10. [PERSON] (Singapore) published the most MMC papers (140, 1.40%) followed by [PERSON] (China) and [PERSON] (China) with 97 (0.97%) and 86 (0.86%) publications, respectively. * 11. [PERSON], [PERSON] and [PERSON] emerged as the MMC researchers with the topmost collaboration based total link strength (TLS) values of 499, 443 and 421, respectively. They published 113, 97 and 117 papers with 108, 110 and 184 co-authors, respectively. [PERSON] did not make it to the top ten collaborative TLS list despite having maximum MMC publications due to less co-author linkages and respective link strengths. * 12. The top three organizations with the maximum inter-institute collaborative TLS values are the Chinese Academy of Science (papers 227, links 73, TLS 212), Harbin Institute of Technology, China (papers 335, links 7, TLS 162) and the Indian Institutes of Technology (papers 223, links 71, TLS 154). * 13. Among the Indian organizations, Anna University attained better inter-organizational collaborative TLS value of 95 as compared to the National Institutes of Technology (TLS 91) despite publishing fewer MMC papers in WoS. * 14. The People's Republic of China, the USA and India attained the highest international collaborative TLS values of 681, 537 and 350, respectively. The authors affiliated with these countries published 2475 (links 42), 1104 (links 47) and 2509 (links 45) articles, respectively. * 15. The MMC researchers of India, Japan, Iran and Spain need to improve international collaborative linkages in proportion to their respective MMC publication outputs. * 16. The review articles published by [PERSON] [113], [PERSON] et al. [105] and [PERSON] [106] were determined to have the highest citations based link strengths of 333, 212 and 200, respectively. These papers obtained 1006, 879 and 552 WoS citations, respectively. * [PERSON] et al. (2016) [PERSON], [PERSON], [PERSON] (all from China) were the top ranked MMC researchers with the highest mutual citations based TLS values of 7016, 5921, 4662 with 3278 (links 777), 2617 (links 733) and 2168 (links 581) citations, respectively. [PERSON] figured at rank 8 of this list despite having maximum citations (3546) due to lesser mutual citations with the documents of other MMC researchers. * The Shanghai Jiao Tong University, Harbin Institute of Technology and the Indian Institutes of Technology attained the maximum citations network based TLS of 4433, 3938 and 3272, respectively. The authors affiliated with these organizations bagged 5323, 5659 and 5109 citations with 544, 565 and 592 links, respectively. * The top three countries with the highest international linkage based TLS rankings are the People's Republic of China (TLS 20878), India (TLS 17501) and the USA (13112).