3 results about "Gd element" patented technology

The invention discloses a creep-resistant magnesium alloy with high elasticity modulus and high damping and a preparation method thereof, and the creep-resistant magnesium alloy with high elasticity modulus and high damping comprises the following components in percentage by mass: 1.2%-3.5% of Zn element, 2.5%-12% of Gd element, 0.5%-6% of Yb element, 0.15%-1.2% of Ni element, 0.3%-0.8% of Mn element, 0-0.5% of Cu element, 0.1%-5% of HRE element and the balance of Mg element. The HRE element is one or more of a Dy element, a Sm element and a Tb element, and the mixing enthalpy delta H of the creep-resistant magnesium alloy with the high elastic modulus and the high damping is-1.1 kJ / mol to-0.2 kJ / mol. The creep-resistant magnesium alloy with high elastic modulus and high damping is suitable for the fields of aerospace, precise instruments, transportation, 3C electronics and the like, and has remarkable technical and economic values.

The application relates to the technical field of preparation of rare earth permanent magnet materials, in particular to a method for improving the brittleness of high-coercivity blank material, which comprises designing the matrix alloy component of a sintered neodymium-iron-boron magnet as follows: Nd a M b N c O d Fe 100‑a‑b‑c‑d‑e B e ; wherein Nd is a neodymium element; M is at least one of La, Ce and Pr elements; N is at least one of Dy, Tb and Gd elements; O is at least one of Co, Mn, Cu, Al, Ti, Ga, Zr, V, Hf, W and Nb elements; Fe is an iron element, and B is a boron element; a, b, c, d and e satisfy the following relations: 27.5 <= a <= 31, 8.5 <= b <= 12, 0.05 <= c <= 0.2, 0 <= d <= 5 and 0.9 <= e <= 1.2; wherein a, b, c, d and e all represent mass percentage contents; the matrix alloy component of the neodymium-iron-boron magnet provided by the application has good toughness of the blank obtained through powdering, forming and sintering, and can effectively avoid the problems of breakage such as edge chipping and corner chipping.

This invention provides a core-shell structure R-T-B rare earth permanent magnet with Gd-rich cores for high-temperature environments. In the magnet, the rare earth element R content is 29.0 wt.% to 34.0 wt.%, and R is composed of Gd and R1. The Gd element content is 1.0 wt.% to 20.0 wt.% of the magnet mass. The main phase grains contain main phase grains with a volume ratio of 20 vol.% to 80 vol.% of Gd-rich cores and Gd-poor shells. This invention employs a dual-alloy method to separately melt alloy sheets with high and low Gd contents, then prepares sintered magnets. During high-temperature diffusion treatment, Gd elements in the high-Gd-content main phase diffuse into the R-rich phase at the grain boundaries. Ultimately, the high-Gd-content main phase grains form an anti-shell structure with a Gd-depleted shell and a Gd-rich core. The Gd-depleted shell significantly reduces the degradative effect of Gd on the magnet's coercivity, thus fully utilizing the characteristics of Gd to prepare a magnet with a low temperature coefficient and high coercivity. Grain boundary diffusion treatment of Dy / Tb elements can further improve the magnet's coercivity, preparing R-T-B rare-earth permanent magnets suitable for higher operating temperatures.