JPH09124371A - Composite material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a composite material excellent in wear resistance against molten metal abrasion and corrosion resistance, having a long life, enabling safe metal melting operation by adding an aggregate to a matrix having specified volume contents of AlN and TiB2 . SOLUTION: This composite material has volume contents in a matrix of >=10% and <=90% of AlN and the rest of TiB2 . An oxide such as alumina, ZrO2 , TiO2 , MgO, SiO2 , or Cr2 O3 , a carbide such as SiC, TiC, ZrC, CrC2 or B4 C, a nitride such as AlN, TiN, ZrN, Si3 N4 , CrN or BN or a boride such as ZrB2 , TiB2 or Cr2 B3 , these compound and mixture are used as the aggregate. The composite material is obtained by weighing 50vol.% of an alumina aggregate having 1-3mm particle diameter and the rest of a matrix of AlN having 1μm average particle diameter and TiB2 having 3μm average particle diameter in the above-mentioned ration and blending the weighed materials, molding the mixture into a crucible-shaped green compact material under 1 ton/cm<2> by a hydraulic press and sintering the molded green compact composition at 1,700 deg.C.

Description

Detailed Description of the Invention

[0001]

The present invention relates to relates to AlN-TiB ₂ matrix composite material comprising a useful aggregate as metal melting refractory materials.

[0002]

2. Description of the Related Art Conventionally, a preform made of an aggregate in a nitrogen atmosphere is composed of an aggregate of AlN and an aggregate of AlN produced by nitriding while raising a molten aluminum or aluminum alloy from the lower surface by a capillary phenomenon. There are composite materials

[0003]

However, the above-mentioned composite material has the following problems. AlN belongs to the lower hardness in ceramics, and therefore, when used as a refractory material for melting metal, it has excellent corrosion resistance to molten metal, but against the abrasion of molten metal that occurs when stirring molten metal or flowing it to the next step. Markedly inferior. When the above-mentioned composite material in which the matrix is only AlN is used as a refractory material, the life of the refractory material is short because the matrix portion is greatly damaged by the abrasion resistance of the molten metal. If the damage progresses further, molten metal will flow out, which is likely to cause a serious disaster.

The present invention has been made in view of the above problems, and exhibits excellent wear resistance against wear of molten metal, has excellent corrosion resistance, and enables long-life and safe metal melting work. The object is to provide a composite material that

[0005]

In the composite material of the present invention, the volume content in the matrix is 10% or more of AlN.
It is characterized in that the content is 0% or less and the balance is TiB ₂ and contains an aggregate. (Reason for limiting AlN volume content in matrix) When AlN in the matrix is less than 10% by volume, TiB ₂
Becomes rich and the corrosion resistance to molten metal is poor. Al
If N exceeds 90%, AlN becomes rich, the hardness becomes low, and it is weak against wear of molten metal. Therefore, the AlN volume content in the matrix is preferably 10% or more and 90% or less.

[0006]

The composite material of the present invention has a volume content of AlN of 10% to 90% and a balance of TiN.
Since it is composed of B ₂ and contains an aggregate, the optimum composite material for a refractory for molten metal, which has excellent corrosion resistance of AlN against molten metal and high hardness of TiB ₂ , has been found. .

[0007]

Example 1 Alumina aggregate having a particle diameter of 3-1 mm was 50% by volume, and the balance of the matrix was as shown in Table 1. AlN having an average particle diameter of 1 micron and TiB ₂ having an average particle diameter of 3 micron were weighed. After mixing these using a wet pan, a crucible-shaped green compact was formed by a hydraulic press. Pressure is 1
It is ton / cm ² . These green compacts were sintered at 1700 ° C. in a nitrogen atmosphere. The following tests were conducted on the obtained crucible sintered body. Table 1 shows the results. 1. Hardness measurement The Vickers hardness of the matrix portion of the above sintered body was measured. 2. Melting test Cast iron FC with the above sintered body installed in an induction furnace
25 was melted at 1450 ° C. for 48 hours, and the amount of erosion was measured after induction stirring.

[0008]

[Table 1]

[0009]

Example 2 In the examples of the present invention, alumina was described as the aggregate, but other oxides: ZrO ₂ , TiO ₂ , MgO, SiO ₂ , Cr ₂ O _3, etc. Carbides: SiC, TiC, ZrC , CrC ₂ , B ₄ C, etc. Nitride: AlN, TiN, ZrN, Si ₃ N ₄ , CrN,
Boron such as BN: ZrB ₂ , TiB ₂ , Cr ₂ B _{3 and the} like, and compounds and mixtures thereof are also included.

[0010]

The composite material of the present invention has a volume content of 10% to 90% of AlN in the matrix and the balance of TiB ₂ and contains an aggregate. Therefore, the corrosion resistance of AlN to molten metal is high. We have found the most suitable composite material for refractory for molten metal, which has excellent wear resistance by utilizing the high hardness of TiB ₂ and TiB ₂ .

Claims (1)

[Claims] 1. The volume content of the matrix is AlN1.
A composite material comprising 0% or more and 90% or less and the balance TiB ₂ and containing an aggregate.