Manufacturing method of high-density lanthanum chromate ceramic heating unit

A ceramic heating element and a manufacturing method technology, which are applied to electric heating devices, heating element materials, ohmic resistance heating, etc., can solve the problems of low yield, rough appearance of the heating element, low strength of the heating element, etc. The effect of good appearance quality and high product strength

Inactive Publication Date: 2017-01-04
BAOTOU RES INST OF RARE EARTHS
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The lanthanum chromate ceramic heating element produced by the existing technology has a relative density of about 80%, and poor tissue compactness; the appearance of the heating element is rough, and macroscopic defects such as cracks and pitting may even appear on the surface, resulting in a low strength of the heating element. The rate is not high, which greatly limits its wide application

Method used

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  • Manufacturing method of high-density lanthanum chromate ceramic heating unit
  • Manufacturing method of high-density lanthanum chromate ceramic heating unit

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0011] A method for manufacturing a high-density lanthanum chromate ceramic heating element specifically includes the following steps:

[0012] (1) Preparation of La 0.8 Ca 0.2 CrO 3 Lanthanum chromate ceramic powder;

[0013] (2) The prepared La 0.8 Ca 0.2 CrO 3 The ceramic powder is loaded into a graphite mold, put into a hot-pressing sintering furnace, and hot-pressed to form a lanthanum chromate ceramic heating element in a vacuum or argon protection environment. The hot-pressing temperature is 1600°C, the molding pressure is 35MPa, and the temperature is kept for 3 hours.

[0014] High-purity lanthanum chromate ceramics can be obtained through the above process, and the X-ray diffraction pattern is shown in the attachment figure 1 . The heating element has good appearance quality, no macro defects such as cracks and cracks, and the surface is smooth and no pitting; the relative density is 98.5%, the structure is dense, and there is no internal porosity. The microstructure photo ...

Embodiment 2

[0016] A method for manufacturing a high-density lanthanum chromate ceramic heating element specifically includes the following steps:

[0017] (1) Preparation of La 0.98 Ca 0.02 CrO 3 Lanthanum chromate ceramic powder;

[0018] (2) The prepared La 0.98 Ca 0.02 CrO 3 The ceramic powder is loaded into a graphite mold, and placed in a hot-pressing sintering furnace to form a lanthanum chromate ceramic heating element under vacuum or argon protection. The hot-pressing temperature is 1700°C, the molding pressure is 30MPa, and the heat preservation and pressure are maintained for 2 hours.

[0019] High-purity lanthanum chromate ceramics can be obtained through the above process. The heating element has good appearance quality, no macro defects such as cracks and cracks, smooth surface and no pitting; the relative density is 98.8%, the structure is dense, and there is no internal porosity.

Embodiment 3

[0021] A method for manufacturing a high-density lanthanum chromate ceramic heating element specifically includes the following steps:

[0022] (1) Preparation of La 0.92 Ca 0.08 CrO 3 Lanthanum chromate ceramic powder;

[0023] (2) The prepared La 0.92 Ca 0.08 CrO 3 The ceramic powder is loaded into a graphite mold, and placed in a hot-pressing sintering furnace to form a lanthanum chromate ceramic heating element under a vacuum or argon protection environment. The hot-pressing temperature is 1850°C, the forming pressure is 25MPa, and the heat preservation and pressure are maintained for 0.5 hours.

[0024] High-purity lanthanum chromate ceramics can be obtained through the above process. The heating element has good appearance quality, no macro defects such as cracks and cracks, smooth surface and no pitting; the relative density is 99.2%, the structure is dense, and there is no internal porosity.

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Abstract

The invention relates to a manufacturing method of a high-density lanthanum chromate ceramic heating unit. The method is characterized by comprising the following steps: (1) preparing lanthanum chromate ceramic powder with the particle size range of 1-100 mu m; and (2) adding the prepared lanthanum chromate ceramic powder into a mold, putting into a hot pressed sintering furnace, and carrying out hot pressing in a vacuum or argon protective atmosphere to obtain the lanthanum chromate ceramic heating unit, wherein the hot pressing temperature is 1600-1850 DEG C, the forming pressure is 25-35 MPa, and the holding time is 0.5-3 hours. The manufactured ceramic has the advantages of high relative density and no pores inside the structure; the heating unit has the advantages of high appearance quality, no crack, subfissure or other macroscopic defects, and smooth surface without pits; and the product has the advantages of high strength and high yield.

Description

Technical field [0001] The invention relates to a method for manufacturing a high-density lanthanum chromate ceramic heating element, which belongs to the field of electric heating heating materials. Background technique [0002] Lanthanum chromate (La 1-x M x CrO 3 , Where M includes one or several alkaline earth elements among Mg, Ca, Sr, and Ba) is a perovskite type composite oxide, and the resistivity of the material decreases with the increase of the doping amount of the divalent alkaline earth element M. The use of lanthanum chromate ceramic material as a heating element has many advantages such as high temperature resistance, oxidation resistance, resistance to corrosion and aging, and high use temperature (up to 1800°C). The current production process of the lanthanum chromate ceramic heating element is to prepare the lanthanum chromate blank through a compression molding, isostatic pressing or extrusion molding process in advance, and then sinter it at a high temperature...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C04B35/50H05B3/14
CPCC04B35/50C04B2235/3208C04B2235/3243H05B3/141
Inventor 刘树峰鲁飞李慧刘小鱼孙良成王峰白洋成宇
Owner BAOTOU RES INST OF RARE EARTHS
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