Abstract
In this review, important aspects of the Hydrogenation, Disproportionation, Desorption and Recombination (HDDR) process are considered. The most surprising feature of the HDDR process in NdFeB (and PrFeB)-type alloys is the development of anisotropy in the Nd2Fe14B phase after recombination of the disproportionated mixture. Early work on this phenomenon reported that alloying additions such as Co and/or Ga were essential in developing the preferred orientation but it has now been shown quite conclusively that appreciable degrees of anisotropy can be developed in the ternary NdFeB alloys provided the appropriate temperatures and hydrogen pressures are employed during disproportionation and recombination. The detailed nature of the anisotropy mechanism still requires clarification but the presence of an intermediate boride could be the deciding factor and would explain the absence of any anisotropy in the Sm3Fe17N3-H2 system.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
