A method for producing a surface-hardened material, comprising: an immersion step of immersing an iron steel material having nitrogen attached in the form of a solid solution on the surface thereof in a melt containing a chloride at a temperature ranging from 650 C. to 900 C.; and a cooling step of cooling the immersed iron steel material to a temperature equal to or lower than a martensitic transformation start temperature at a cooling rate equal to or higher than a lower critical cooling rare at which martensitic transformation starts.

Composite structures having a reinforced material intermingled with a substrate wherein the reinforced material includes titanium monoboride, titanium diboride, or a combination thereof.

Composite structures having a reinforced material intermingled with a substrate wherein the reinforced material includes titanium monoboride, titanium diboride, or a combination thereof.

The present invention discloses a rare earth permanent magnet material and a preparation method thereof The method comprises: a sintering treatment step: laying a composite powder for diffusion on the surface of a neodymium iron boron magnetic powder layer and carrying out spark plasma sintering treatment to obtain a neodymium iron boron magnet with a diffusion layer solidified on the surface thereof, wherein the compositional proportional formula of the composite powder for diffusion is H.sub.100-x-yM.sub.xQ.sub.y, where H is one or more of a metal powder, a fluoride powder, or an oxide powder of Dy, Tb, Ho, and Gd, M is a Nd, Pr, or NdPr metal powder, and Q is one or more of Cu, Al, Zn, and Sn metal powders, x and y are respectively the atomic percentages of component M and component Q in the composite powder for diffusion, x is 0-20, and y is 0-40; and diffusion heat treatment and tempering steps. The method of the present invention has high efficiency, good diffusion effects, and reduced quantities of heavy rare earth elements.

A method for improvement of magnetic performance of sintered NdFeB magnet includes the following steps. Firstly, material containing element R, H and X is to be covered on a surface of the sintered NdFeB magnet to form a finish coat. After that, proceed with a diffusion treatment and an aging treatment to the sintered NdFeB magnet with the finish coat in the environment of vacuum or inert gas. R is at least one of such elements as Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu. H is hydrogen. X is at least one of such elements as C, O, N, S, B, Cl and Si.

A method for improvement of magnetic performance of sintered NdFeB magnet includes the following steps. Firstly, material containing element R, H and X is to be covered on a surface of the sintered NdFeB magnet to form a finish coat. After that, proceed with a diffusion treatment and an aging treatment to the sintered NdFeB magnet with the finish coat in the environment of vacuum or inert gas. R is at least one of such elements as Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu. H is hydrogen. X is at least one of such elements as C, O, N, S, B, Cl and Si.

A rare earth sintered magnet is produced by depositing a coating of rare earth-containing particles on the surface of a rare earth magnet body, and heat treating the magnet body for causing absorption and diffusion of rare earth element in the magnet body. The depositing step utilizes a particle impingement phenomenon.

A rare earth sintered magnet is produced by depositing a coating of rare earth-containing particles on the surface of a rare earth magnet body, and heat treating the magnet body for causing absorption and diffusion of rare earth element in the magnet body. The depositing step utilizes a particle impingement phenomenon.

A method of hardening a surface of a ferro-alloy object, the method comprising at least partially gasifying a carbon-containing polymer to form a hardening material source; and exposing the object to the hardening material source, such that the hardening material source and the surface of the object react, thereby hardening the surface of the object.

The present invention discloses a rare earth permanent magnet material and a preparation method thereof. The method includes a sintering treatment step performed by laying a composite powder for diffusion on the surface of a neodymium iron boron magnetic powder layer and carrying out spark plasma sintering treatment to obtain a neodymium iron boron magnet with a diffusion layer solidified on the surface thereof, and diffusion heat treatment and tempering steps. The method of the present invention has high efficiency, good diffusion effects, and reduced quantities of heavy rare earth elements.