Iron-hafnium-rare earth master alloy and preparation method thereof

Abstract

The invention discloses an iron-hafnium-rare earth intermediate alloy. The intermediate alloy comprises 10-30 wt% of hafnium, 50-85 wt% of iron and 5-20 wt% of rare earth metal. The invention also provides a preparation method of the intermediate alloy. The method comprises the following steps: preparing materials according to above weight percentages of above elements in the alloy, adding the iron, hafnium and rare earth metal raw materials into a crucible, and placing the crucible in a vacuum melting furnace; and performing vacuumizing until the vacuum degree in the melting furnace is -0.1 MPa or less, introducing a protective gas to maintain the vacuum degree at -0.08 to -0.06 MPa, heating the melting furnace to 1400-1500 DEG C, melting the raw materials for 15-30 min, adding the obtained alloy solution into a die, performing cooling molding, and performing demolding to obtain the iron-hafnium-rare earth intermediate alloy. The iron-hafnium-rare earth intermediate alloy prepared bythe method has uniform composition and wide applicability, and can be especially used as an additive for rare earth permanent magnet materials and high-temperature alloy steels.

Description

technical field [0001] The invention belongs to the technical field of alloy preparation of metal materials, and in particular relates to an iron-hafnium-rare earth master alloy and a preparation method thereof. Background technique [0002] Rare earth metal is one of the main components of rare earth permanent magnet materials, and the addition amount can reach 30wt%. After adding, the magnetic properties of permanent magnet materials can be improved, but it has no effect on improving the high temperature magnetism of permanent magnet materials, so there are defects. Metal hafnium can greatly improve the high-temperature anti-demagnetization performance of permanent magnet materials, but hafnium has high chemical activity, extremely high melting point, and is easy to burn out at high temperatures, making it difficult to add, so it can only be added in the form of an intermediate alloy. At the same time, hafnium and rare earth metals are difficult to form alloys, so in order...

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Problems solved by technology

Metal hafnium (generally hafnium sponge) has a high melting point of 2227°C, is extremely difficult to melt under normal temperature and pressure, and is severely burned in the air, which is not conducive to the alloying process and consumes a lot of energy. Therefore, the iron-hafnium intermediate alloy It can only be prepared by vacuum smelting method; for example, Chinese patent application CN102534350A discloses a method for manufacturing a new type of iron-based alloy target. Melting to obtain an iron-hafnium alloy target with a hafnium content of 30.9-31.0%. This method has a simple process and is easy to operate. However, according to the results of reverse engineering, this process has the problems of high energy consumption, high cost, and serious impurities. The obtained iron Hafnium alloy targets cannot meet the requirements of low cost and uniform composition of rare earth permanent magnet material additives, which seriously affects the popularization and application of hafnium master alloys