Sintering method for high saturated flux density MnZn ferrite

Abstract

This invention provides a sintering method for a high-saturated flux density MnZn ferrite including the following steps: a, a first temperature-rising stage, b, a second temperature-rising stage, c, a heat preservation stage, d, temperature-reducing, which can increase the saturated flux density of MnZn ferrite greatly by controlling the temperature and oxygen partial pressure during the sintering process, besides, no expensive asistant components are needed in the preparation process.

Description

technical field

[0001] The invention relates to a sintering method of MnZn ferrite, in particular to a sintering method of MnZn ferrite with high saturation magnetic flux density. Background technique

[0002] MnZn ferrite can be used as a soft magnetic material and is widely used in power transformers, choke coils and other communication equipment and household appliances industries. When used in the power transformer core used in the frequency range of 100kHz to hundreds of kHz, compared with other ferrite materials and metal soft magnetic materials, MnZn ferrite has small power consumption and large saturation flux density, so MnZn ferrite Oxygen is an important material as a transformer core.

[0003] However, with the miniaturization of electronic equipment and high output power of power supplies, and in order to be used normally under high temperature conditions, the saturation magnetic flux density (Bs) of ordinary MnZn ferrite materials, especially high temperature ...

Examples

Embodiment 1

[0022] will consist of 53mol% Fe 2 o 3 , 11mol% ZnO, 36mol% MnO raw materials were mixed in a sand mill for 1 hour, and then pre-fired at 800°C for 2 hours. Add auxiliary component in above-mentioned calcined material, the auxiliary component (wt%) that adds is: the CaCO of 0.1wt% 3 , 0.03wt% Nb 2 o 5 , 0.03wt% ZrO 2 , 0.1wt% SnO 2 . Then carry out secondary sand grinding for 2 hours, spray granulation after adding PVA, and shape it into a standard annular magnetic core of Φ25 for sintering. In the sintering process, the first heating stage is from room temperature to 600°C, the heating time is 4 hours, and the heating is carried out in the atmosphere; the second heating stage is from 600°C to 1300°C , the heating time is 6 hours, and the oxygen partial pressure in the heating stage is maintained at 0.5%; at 1300°C for 5 hours, the oxygen partial pressure is maintained at 6%; finally, the cooling time is 10 hours from 1300°C to 100°C, The process maintains an equilibri...

Embodiment 2

[0027] will consist of 53.8mol% Fe 2 o 3 , 7mol% ZnO, 39.2mol% MnO raw materials were mixed in a sand mill for 1 hour, and then pre-fired at 850°C for 2 hours. Add auxiliary component in above-mentioned calcined material, the auxiliary component (wt%) that adds is: the CaCO of 0.12wt% 3 , 0.02wt% Nb 2 o 5 , 0.04wt% ZrO 2 . Then carry out secondary sand grinding for 2 hours, spray granulation after adding PVA, and shape it into a standard annular magnetic core of Φ25 for sintering. In the sintering process, the first heating stage is from room temperature to 800°C, the heating time is 5 hours, and the heating is carried out in the atmosphere; the second heating stage is from 800°C to 1320°C , the heating time is 5 hours, and the oxygen partial pressure in the heating stage is maintained at 0.1%; at 1320°C for 3 hours, the oxygen partial pressure is maintained at 8%; finally, the temperature is lowered from 1320°C to 100°C, and the cooling time is 11 hours. The process ma...

Embodiment 3

[0032] will consist of 53.2mol% Fe 2 o 3 , 9mol% ZnO, 37.8mol% MnO raw materials were mixed in a sand mill for 1 hour, and then pre-fired at 900°C for 2 hours. Add auxiliary component in above-mentioned calcined material, the auxiliary component (wt%) that adds is: the CaCO of 0.13wt% 3 , 0.015wt% Nb 2 o 5 , 0.05wt% ZrO 2 . Then carry out secondary sand grinding for 2 hours, spray granulation after adding PVA, and shape it into a quasi-ring magnetic core of Φ25 for sintering. In the sintering process, the first heating stage is from room temperature to 600°C, the heating time is 1 hour, and the heating is carried out in the atmosphere; the second heating stage is from 600°C to 1150°C , the heating time is 3 hours, and the oxygen partial pressure in the heating stage is maintained at 2%; at 1150°C for 8 hours, the oxygen partial pressure is maintained at 10%; The process maintains an equilibrium oxygen partial pressure.

[0033] The Bs of the sample was tested with a SY...

technical field

[0001] The invention relates to a sintering method of MnZn ferrite, in particular to a sintering method of MnZn ferrite with high saturation magnetic flux density. Background technique

[0002] MnZn ferrite can be used as a soft magnetic material and is widely used in power transformers, choke coils and other communication equipment and household appliances industries. When used in the power transformer core used in the frequency range of 100kHz to hundreds of kHz, compared with other ferrite materials and metal soft magnetic materials, MnZn ferrite has small power consumption and large saturation flux density, so MnZn ferrite Oxygen is an important material as a transformer core.

[0003] However, with the miniaturization of electronic equipment and high output power of power supplies, and in order to be used normally under high temperature conditions, the saturation magnetic flux density (Bs) of ordinary MnZn ferrite materials, especially high temperature ...

Examples

Embodiment 1

[0022] will consist of 53mol% Fe 2 o 3 , 11mol% ZnO, 36mol% MnO raw materials were mixed in a sand mill for 1 hour, and then pre-fired at 800°C for 2 hours. Add auxiliary component in above-mentioned calcined material, the auxiliary component (wt%) that adds is: the CaCO of 0.1wt% 3 , 0.03wt% Nb 2 o 5 , 0.03wt% ZrO 2 , 0.1wt% SnO 2 . Then carry out secondary sand grinding for 2 hours, spray granulation after adding PVA, and shape it into a standard annular magnetic core of Φ25 for sintering. In the sintering process, the first heating stage is from room temperature to 600°C, the heating time is 4 hours, and the heating is carried out in the atmosphere; the second heating stage is from 600°C to 1300°C , the heating time is 6 hours, and the oxygen partial pressure in the heating stage is maintained at 0.5%; at 1300°C for 5 hours, the oxygen partial pressure is maintained at 6%; finally, the cooling time is 10 hours from 1300°C to 100°C, The process maintains an equilibri...

Embodiment 2

[0027] will consist of 53.8mol% Fe 2 o 3 , 7mol% ZnO, 39.2mol% MnO raw materials were mixed in a sand mill for 1 hour, and then pre-fired at 850°C for 2 hours. Add auxiliary component in above-mentioned calcined material, the auxiliary component (wt%) that adds is: the CaCO of 0.12wt% 3 , 0.02wt% Nb 2 o 5 , 0.04wt% ZrO 2 . Then carry out secondary sand grinding for 2 hours, spray granulation after adding PVA, and shape it into a standard annular magnetic core of Φ25 for sintering. In the sintering process, the first heating stage is from room temperature to 800°C, the heating time is 5 hours, and the heating is carried out in the atmosphere; the second heating stage is from 800°C to 1320°C , the heating time is 5 hours, and the oxygen partial pressure in the heating stage is maintained at 0.1%; at 1320°C for 3 hours, the oxygen partial pressure is maintained at 8%; finally, the temperature is lowered from 1320°C to 100°C, and the cooling time is 11 hours. The process ma...

Embodiment 3

[0032] will consist of 53.2mol% Fe 2 o 3 , 9mol% ZnO, 37.8mol% MnO raw materials were mixed in a sand mill for 1 hour, and then pre-fired at 900°C for 2 hours. Add auxiliary component in above-mentioned calcined material, the auxiliary component (wt%) that adds is: the CaCO of 0.13wt% 3 , 0.015wt% Nb 2 o 5 , 0.05wt% ZrO 2 . Then carry out secondary sand grinding for 2 hours, spray granulation after adding PVA, and shape it into a quasi-ring magnetic core of Φ25 for sintering. In the sintering process, the first heating stage is from room temperature to 600°C, the heating time is 1 hour, and the heating is carried out in the atmosphere; the second heating stage is from 600°C to 1150°C , the heating time is 3 hours, and the oxygen partial pressure in the heating stage is maintained at 2%; at 1150°C for 8 hours, the oxygen partial pressure is maintained at 10%; The process maintains an equilibrium oxygen partial pressure.

[0033] The Bs of the sample was tested with a SY...