Method for producing ferrite ceramic

Patent metadata

Field	Value
Publication number	US-9403727-B2
Application number	US-201414486082-A
Country	US
Kind code	B2
Filing date	Sep 15, 2014
Priority date	Oct 22, 2013
Publication date	Aug 2, 2016
Grant date	Aug 2, 2016

Abstract

A method for producing ferrite ceramic includes the steps of providing a ferrite powder; oven-drying the ferrite powder; adding organic additives into the oven-dried powder and mixing them to form a ferrite slurry; debubbling the ferrite slurry and then tape casting it into a green tape; heating the green tape in air to 300-500° C. for 5 h to remove the organic additives from the green tape; sintering the organic additives removed green tape at 900-1000° C. for 2-5 h to obtain ferrite ceramic.

First claim

What is claimed is:

1. A method for producing ferrite ceramic, comprising the steps of:
material preparation: providing a ferrite powder;
oven-drying: oven-drying the ferrite powder;
pulping: adding dispersing agent and solvent into the ferrite powder, mixing and wet milling them in a ball mill for 20 h for obtaining a mixture; adding binder and plasticizer into the mixture, and wet milling them in the ball mill for 20 h for obtaining the ferrite slurry; wherein, the ferrite slurry comprises: 100 wt. % of the ferrite powder; 30 wt. % to 55 wt. % of toluene and 10 wt. % to 20 wt. % of alcohol as the solvent 0.1 wt. % to 2 wt. % of a dispersing agent 7 wt. % to 15 wt. % of a first polyvinyl butyral and 1.5 wt. % to 5 wt. % of a second polyvinyl butyral as the binder;
and 2 wt. % to 5 wt. % of dibutyl phthalate as the plasticizer;
forming: debubbling the ferrite slurry and then tape casting it into a green tape;
organic additives removal: heating the green tape in air to 300-500° C. for 5 h for removing the organic additives from the green tape;
sintering: sintering the green tape from which the organic additives have been removed at 900-1000° C. for 2-5 h for obtaining ferrite ceramic.

2. The method for producing ferrite ceramic of claim 1 , wherein the material preparation step further comprises the steps of:
providing ferrite as raw material;
pulverizing the ferrite into the ferrite powder in a ball-mill.

3. The method for producing ferrite ceramic of claim 2 , wherein in the step of material preparation, the ferrite powder has a median particle size of from 0.5 μm to 3.5 μm.

4. The method for producing ferrite ceramic of claim 1 , wherein in the step of oven-drying, oven-drying the ferrite powder until a water content of the ferrite powder reduces to below 0.1 wt. %.

5. The method for producing ferrite ceramic of claim 1 , wherein in the step of forming, debubbling the ferrite slurry by heating and vacuum pumping.

6. The method for producing ferrite ceramic of claim 1 , wherein, a molecular weight of the first polyvinyl butyral is in the range of 50000 to 70000, and a molecular weight of the second polyvinyl butyral is in the range of 100000 to 120000.

Assignees

• Su Shaohua
• Yu Jinhui
• Aac Technologies Pte Ltd

Inventors

• Su Shaohua
• Yu Jinhui

Classifications

• C04B2235/6567

  Treatment time · CPC title

• C04B35/62655

  Drying, e.g. freeze-drying, spray-drying, microwave or supercritical drying · CPC title

• C04B2235/5436

  micrometer sized, i.e. from 1 to 100 micron · CPC title

• C04B35/6261

  Milling · CPC title

• C04B35/6264

  Mixing media, e.g. organic solvents · CPC title