6results about How to "Increased Diffusion Depth" patented technology

The invention relates to a method for improving the binding force of a neodymium-iron-boron magnet coating and application. The method comprises the steps that rare earth hydroxide suspension liquid is prepared; spraying double surfaces of the neodymium-iron-boron magnet; and carrying out grain boundary thermal diffusion treatment. According to the method, the rare earth hydroxide is pyrolyzed into the rare earth oxide to be deposited on the surface of the sintered neodymium-iron-boron magnet, the diffusion depth of heavy rare earth elements in the magnet can be effectively increased, and the components and thickness of the coating are accurately controlled; the cost of preparing the rare earth oxide from the rare earth hydroxide is saved, the preparation process of the diffusion source is simplified, and the spraying efficiency is high; the obtained coating is high in quality and low in porosity, and the bonding strength of a diffusion source and a magnet interface is high; subsequent grain boundary diffusion can be promoted, and a new thought is provided for industrial application of the grain boundary diffusion technology.

The application discloses a kind of bistable suction disc devices for enhancing the performance of microneedle and preparation method thereof, belong to medical instrument technical field, the bistable suction disc device structure includes elastic hemispherical shell, and the outer wall of elastic hemispherical shell is provided with convex column, and the axis of convex column and elastic hemispherical shell coincides, and the inner wall of elastic hemispherical shell is provided with microneedle patch mounting platform, and microneedle patch mounting platform is located just below the convex column, and the platform is combined with microneedle patch;Elastic hemispherical shell includes first stable state and second stable state, and first stable state is open downward state, and second stable state is open upward state, and it changes first stable state and second stable state when using, so that the negative pressure area between the inner wall of elastic hemispherical shell and skin, enhance the drug delivery efficiency of microneedle on microneedle patch and skin interstitial fluid collection amount.The bistable suction disc device has wide application prospect in the field of biomedicine.

The invention provides a preparation method of a high-performance grain boundary diffusion sintered neodymium iron boron material, and belongs to the technical field of permanent magnet materials. The low-melting-point heavy-rare-earth-free alloy coating is coated and cured on the easy-to-diffuse surface of the neodymium-iron-boron base material magnet, and the heavy-rare-earth alloy coating is coated and cured on the low-melting-point heavy-rare-earth-free alloy coating; and the coated magnet is sequentially subjected to low-temperature pre-diffusion heat treatment, grain boundary diffusion heat treatment and aging treatment, and then the grain boundary diffusion neodymium-iron-boron magnet is obtained. According to the invention, the diffusion efficiency of heavy rare earth elements can be effectively improved, the coercive force of the magnet is improved, and relatively high residual magnetism can be achieved.

The invention provides a composite diffusant for grain boundary diffusion of a neodymium-iron-boron magnet, a grain boundary diffusion method of the neodymium-iron-boron magnet and the neodymium-iron-boron magnet. The composite diffusant comprises 20 wt%-50 wt% of a diffusion precursor, 50 wt%-80 wt% of a diffusion alloy and 0.5 wt%-5 wt% of an additive. The diffusion precursor comprises one or more of magnesium oxide and zinc oxide; the diffusion alloy comprises an RAlCu alloy, wherein R represents one or more of La, Ce, Pr, Nd, Dy and Tb; the additive comprises an Al70Cu30 alloy and a first thermoplastic binder, and the mass fraction of the Al70Cu30 alloy is greater than or equal to 40% based on the total mass of the additive. The composite diffusant can reduce the use amount of heavy rare earth during grain boundary diffusion of the neodymium-iron-boron magnet, the diffusion efficiency is improved, the diffusion process is simplified, and the magnet performance is improved.

The present disclosure relates to a sintered Nd-Fe-B magnet and a method for preparing the sintered Nd-Fe-B magnet, the method comprising the following steps: S1, preparing a sintered Nd-Fe-B magnet substrate; S2, attaching a diffusion source containing RE to the surface of the sintered Nd-Fe-B magnet substrate, and then performing grain boundary diffusion treatment and tempering treatment; RE is Dy and / or Tb; wherein the grain boundary diffusion treatment comprises an initial diffusion heat treatment and N stages of diffusion process segments, N≥1, each stage of the diffusion process segment comprises, in sequence, a high-temperature diffusion heat treatment and a low-temperature diffusion heat treatment; the low-temperature diffusion heat treatment has a temperature of 850-950 ℃ and a time of 6-12 h; the high-temperature diffusion heat treatment has a temperature lower than the sintering temperature and 50-200 ℃ higher than the temperature of the low-temperature diffusion heat treatment, and a time of 2-8 h. The method can promote the diffusion of heavy rare earth elements to the central region of the sintered magnet in the grain boundary diffusion process, and further improve the comprehensive magnetic properties of the sintered Nd-Fe-B magnet.

The application discloses a grain boundary diffusion material, a neodymium-iron-boron magnet material and a preparation method and application thereof. The grain boundary diffusion material comprises a sintered body and a diffusion source. The sintered body comprises the following components: R: 29-32 wt.%, R being a rare earth element; M: 0.1-2 wt.%, M comprising one or more of Cu, Ga and Co; B: 0.9-1.0 wt.%; Fe: 65-70 wt.%, wt.% being the percentage of the mass of each component to the total mass of the sintered body. The diffusion source comprises the following components: Tb: 60-85 wt.%; Ga: 10-30 wt.%; Cu: 5-20 wt.%, wt.% being the percentage of the mass of each component to the total mass of the diffusion source. The grain boundary diffusion material can significantly improve the coercivity of the neodymium-iron-boron magnet material, while maintaining high remanence and high-temperature stability of the magnetic performance.