Central Iron and Steel Research Institute

Beijing Xingchen Modern Control Engineering Institute

Anhua Li

Wei Li

Haibo Feng

Yang Zhao

Yanfeng Li

Min Tan

Jingdai Wang

Shulin Huang

Minggang Zhu

Yachao Sun

Longlong Xi

Jianguang Sun

Haojun Zhu

Yunzheng Li

The present invention relates to a Ce-containing sintered rare earth permanent magnet with high toughness and high coercivity and a method of preparing the magnet, belonging to the technical field of rare earth permanent magnetic materials. The magnet is prepared by steps of raw material batching, strip casting, hydrogen decrepitation and jet milling, powder orientating and forming, sintering and heat treatment. The materials of the permanent magnet comprise the main phase alloy powders and the Ce added phase alloy powders, wherein the Ce added phase alloy is a magnetic phase or a non-magnetic liquid-phase alloy; and the Ce added phase alloy accounts for 5% to 30% of the total weight of the permanent magnet, and the remainder is the main phase alloy. During the jet milling stage, a certain concentration of oxygen is added into the inert gas, so that the final magnet has an oxygen content of 1500 to 2500 ppm. The Ce-containing dual-alloy magnet prepared in accordance with the present invention has high coercivity, and the intrinsic coercivity (H) is up to 17 to 28.73 kOe. The magnet of the present invention has good fracture toughness which is increased by 10% to 30% as compared with the conventional Nd&#x2014;Fe&#x2014;B sintered magnet. The magnet of the present invention can meet needs of high-end applications such as wind power generation, new energy vehicles, and the like, and greatly expands the application fields of Ce-containing magnets.

Ce-containing sintered rare-earth permanent magnet with having high toughness and high coercivity, and preparation method therefor

The invention discloses a low-cost double-main-phase Ce permanent magnet alloy and its preparation method, and belongs to technical field of rare earth permanent magnet material. The Ce permanent magnet alloy has a chemical formula of (Ce,Re)FeBTMin mass percent, wherein 0.4&#x2266;x&#x2266;0.8, 29&#x2266;a&#x2266;33, 0.8&#x2266;b&#x2266;1.5, 0.5&#x2266;c&#x2266;2, Re is one or more selected from Nd, Pr, Dy, Tb and Ho elements, and TM is one or more selected from Ga, Co, Cu, Nb and Al elements; the Ce permanent magnet alloy has a double-main-phase structure with a low Hphase in (Ce,Re)&#x2014;Fe&#x2014;B and a high Hphase in Nd&#x2014;Fe&#x2014;B. The double-main-phase Ce permanent magnet alloy of the present invention prepared by using a double-main-phase alloy method greatly lowers the production cost of magnet while maintaining excellent magnetic performances.

Low-cost double-main-phase Ce permanent magnet alloy and its preparation method

The present invention relates to a degradable starch resin composition, a process for preparing the same and the use thereof. Said composition comprises starch, synthetic resin, mixing promoter, plasticizer, degradation accelerator and other additives. Said process comprising: (a) selecting a biodegradation accelerator; (b) preparing modified starch concentrate; (c) extruding the modified starch, EAA and the synthetic resin in a double-screw extruder and pelleting to obtain the degradable starch resin. The composition of the present invention contains a biodegradation accelerator and its starch content can be up to 80%. Having excellent biodegradability and good physico-mechanical property, the composition is particularly suitable to be used to prepare various light or heavy packaging films and agricultural films, etc.

Biodegradable composition, a process for preparing the same and the use

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Beijing, China

Anhua Li