WO2007024158A2

WO2007024158A2 - Aluminium-based powder composite mixture and method for the production thereof

Info

Publication number: WO2007024158A2
Application number: PCT/RU2006/000441
Authority: WO
Inventors: Jurij Vasilievich Shmakov; Boris Vladimirovich Golovchanskij; Marina Valerievna Zenina; Konstantin Alekseevich Andrianov; Marina Ilinichna Vedernikova; Efim Leonidovich Mezhiritskij; Aleksej Borisovich Petrenko
Original assignee: Federal'noe Gosudarstvennoe Unitarnoe Predprijatie 'nauchno-Proizvodstvennyj Tsentr Avtomatiki I Priborostroenija Im. Akademika N.A. Piljugina' Fgup 'npc Ap'
Priority date: 2005-08-22
Filing date: 2006-08-22
Publication date: 2007-03-01
Also published as: CN101273149B; RU2288292C1; CN101273149A; WO2007024158A8; WO2007024158A3

Abstract

The invention relates to powder metallurgy. The inventive aluminium-based powder composite mixture comprises components with the following component ratio: 41-43 mass % silicon, 4,1-5.2 mass % nickel, 0.05-0.1 mass % phosphorus and 0.01-0.05 mass % aluminium nitride, the rest being aluminium. The inventive method for producing said powder composite mixture consists in preparing a melt containing aluminium, silicon and nickel and, subsequently, in pulverising said melt by nitrogen at a temperature and pressure which enable the aluminium nitride to be formed. Said invention makes it possible to obtain a construction material which exhibits a high operating performance, a high operational reliability for a long service life, is non-toxic and inexpensive. The thus obtainable material can be used for accurate engineering products, in particular for aircraft instruments.

Description

POWDER COMPOSITION MIX ON THE BASIS

ALUMINUM AND METHOD FOR PRODUCING IT

Technical field

The invention relates to powder metallurgy and may be

used in various fields of national economy,

(instrument-making, aerospace, rocket, shipbuilding,

automotive, textile, etc.), in which a combination of such

product properties such as: low coefficient of linear expansion,

high dimensional stability, low specific gravity,

Satisfactory machinability and environmental friendly.

State of the art

It is known that currently one of the main

construction materials, for example, for the manufacture of command

instrumentation control systems of aircraft is beryllium,

providing the necessary requirements for instrument parts: small

specific gravity, low linear expansion coefficient, high

dimensional stability, vacuum tightness, etc. (Nikitin E.A., Shestov

CA. Matveev V.A. "Gyroscopic systems. Elements

gyroscopic instruments ", M .: Higher school, 1988, 432 s).

The main disadvantage of this material is the high

the complexity of its manufacture, high cost and its toxicity with

processing. Known composite material, which consists of an alloy on

aluminum base with additives of 25% silicon, 5% nickel and refractory

compounds of 15% silicon nitride (RF Patent M 2016 120, IPC class C22C

21/14, 32/00 from 17.05.91).

The disadvantage of this material is the inability to provide

reliability and stability of the required operational characteristics in

for a long service life.

Known powder composite material, which consists of

aluminum-based alloy with additives of silicon and nickel and refractory

component in the form of crystalline silicon powder, which

closest in physical and mechanical properties to beryllium (RF Patent

W 2149201, IPC class C22 C 21/14, 32/00 dated 05/20/2000).

The disadvantage of this material is the low technological

ductility, instability, performance due to

structural heterogeneity, the presence of gas porosity increased

specific gravity and linear expansion coefficient, which reduces

reliability of the product.

Known powder composite material, which consists of

aluminum-based alloy with additives of silicon, beryllium, oxide

aluminum and a refractory component in the form of crystalline silicon

(RF patent jvfo 2175682, IPC class C22 C 21/02, 1/04 dated 10.11.2001),

adopted as the closest analogue (prototype) of the proposed inventions.

The disadvantage of this material is the presence of structural

heterogeneity, reduced technological ductility, use in

as an alloying component of the toxic element of beryllium.

A known method for producing a composite material, including

production of a melt containing aluminum, copper, magnesium, addition

silicon carbide powder (Romanova B.C., Trubkina K.M. "Production

pressed semi-finished products from a powder composite and their study

properties "Sat. Technology of light alloys, VILS, 1993, Ne 12, S. 49-53).

The disadvantages of this method are the increased density,

linear expansion coefficient and insufficient dimensional

material stability.

A known method for producing a composite material, including

the manufacture of a melt containing aluminum, silicon, Nickel,

spraying, adding silicon powder (RF Patent JMb 2149201, MIL cl.

C22 C 21/14, 32/00 dated 05/20/2000).

The disadvantage of this method is the instability

operational characteristics of the material and its unreliability

long service life due to structural

heterogeneity, the presence of gas porosity and insufficient dimensional

stability.

A known method of producing a composite material, including the manufacture of a melt containing aluminum, silicon,

nickel, beryllium, alumina, spraying, powder addition

silicon (RF Patent jsfe 2175682, IPC class C22C 21/02, 1/04 of 11/10/2001),

adopted as the closest analogue of the invention

(prototype).

The disadvantage of this method is the inability to provide

stable performance over the long term

product service.

Summary of the invention

The problem is solved in that the powder composite

aluminum-based mixture containing silicon, nickel, according to

the invention further comprises phosphorus and aluminum nitride at

next component ratio, may. %:

- silicon - 41 ÷ 43

- nickel - 4, l ÷ 5.2

- phosphorus - 0.05 ÷ 0, l

- aluminum nitride - 0.01 ÷ 0.05

- aluminum - the rest

A method of obtaining a powder composite mixture, including

the manufacture of a melt containing aluminum, silicon, Nickel,

spraying, adding powdered silicon, upon receipt, according to the invention, phosphorus is additionally introduced into it, and spraying

the melt is conducted with nitrogen at a temperature and pressure, providing

the formation of aluminum nitride in the required volume.

The proposed composition of the powder mixture and method for its preparation

allow:

- firstly, implement a mechanism for modifying primary

silicon crystals by hindering their growth due to adsorption of atoms

phosphorus on the faces of growing crystals, as well as an increase in the number of centers

crystallization - crystallizable clusters (Si _k );

- secondly, due to the joint interaction of the process

modification, the formation of the nitride phase (AlN) to achieve more

high cooling rate of the dispersible melt and, as a result, -

lower growth rates and more even distribution as

primary silicon crystals and intermetallic phases NiAl ₃ , FeAl ₃ ,

AlN, AlP in the volume of the matrix of the solid solution of each particle;

- thirdly, the formation of the nitride phase on the juvenile surface

powder particles contributes to the intensification of diffusion processes

in the subsequent redistribution of the powder into a semi-finished product. This leads to

that the structure of the material is an α-solid solution of aluminum with

finely dispersed and evenly distributed precipitates in it

silicon crystals and intermetallic phases NiAl ₃ , FeAl ₃ , AlN, AlP.

A similar structure is characterized by a sharp reduction in the distance between silicon crystals and intermetallic phases and ₅ as a consequence,

a significant increase in the surface of their contact with aluminum

matrix.

As a result of this, an increase in the strength of interparticle

bonds promoting physical and mechanical properties

material, including elastic modulus. High modulus material

elasticity is characterized by the presence of rigid bonds in the structure, with

whose attractive forces act stronger than the repulsive forces.

In this regard, the elastic modulus, being the reciprocal of

coefficient of linear expansion, contributes to the fact that the resulting

the material is less susceptible to expansion under the influence of temperature.

All this contributes to the production of a material with the structure of α-solid

aluminum solution with dispersed uniformly distributed in it

silicon crystals and intermetallic phases NiAl ₃ , FeAl ₃ , AlN, AlP,

improving mechanical properties, reducing specific gravity and

linear expansion coefficient, increase dimensional stability,

vacuum tightness and technological plasticity.

Content of components (silicon, nickel, phosphorus, nitride

aluminum) less than this will not allow to achieve α-solid in the matrix

aluminum solution additional dispersion and uniform

distribution of primary silicon crystals of intermetallic phases (type

NiAl ₃ , FeAl ₃ , AlN, AlP) and the possibility of the formation of a nitride phase. it leads to both a decrease in strength and the strength of interparticle bonds in

generally between the aluminum matrix and the carbon-metal phases. As a result

This reduces the strength and plastic characteristics, including

modulus of elasticity, the coefficient of linear expansion increases, decreases

dimensional stability, as well as technological plasticity of the material.

The content of components (silicon, nickel, phosphorus, aluminum nitride) is higher

indicated due to overmodification of the melt leads to an increase in size

primary silicon crystals, which affects uniformity

structure and, as a result, an increase in the coefficient of linear expansion,

decrease in dimensional stability and technological plasticity.

Description of Embodiments

Examples of obtaining a powder composite mixture:

They took pig aluminum grade no lower than A7, crystalline

KpO grade silicon; pure nickel H-I; red phosphorus in the form

compressed tablets wrapped in aluminum foil and loaded into

a melting furnace in which the melt was prepared. Upon reaching temperature

melt 1300 ⁰ C, nitrogen was introduced into it, and after holding for 30 minutes.

the melt was sprayed with nitrogen at a pressure of at least 10 atm per powder,

which was then mixed with powdered silicon. Powder

the composite mixture was poured into technological capsules, degassed in

vacuum at a residual discharge of 1D0 ^"3 ÷ 1.10 ^{" 4} mm Hg and then

pressed on a hydraulic press with a force of 950 i.e. Compact

the workpieces were machined and their physical mechanical properties.

Options for the content of components in powder composite

mixtures of the corresponding: proposed, prohibitive (with values

smaller or larger specified component limit values

the proposed method), as well as the well-known closest analogue

(prototype) are presented in table I.

Table 2 shows the properties of the composite blanks

materials obtained from the investigated powder composite

mixtures.

Data analysis of physical and mechanical properties of powder

composite materials shown in table 2, allow you to do

the conclusion that the best technical result is achieved when

using a powder composite mixture with the proposed

content of components, which allows to obtain powder

composite material superior to all known materials

defining characteristics of this class of materials.

Thus, using the indicated component content in

powder composite mixture and the proposed method we obtain

material possessing: uniformity and fineness of the structure,

high physical and mechanical properties, lower coefficient

linear expansion, high dimensional stability and higher

vacuum tightness. Thus, the proposed powder composite mixture

allows to obtain material with high operational

characteristics and high operational reliability during

long life of the product, as well as this material is

non-toxic and inexpensive.

POWDER COMPOSITION MATERIAL BASED ON ALUMINUM

AND METHOD FOR ITS PRODUCTION

Table 1

o Table 2 ι

Claims

CLAIM

1. Powder composite mixture based on aluminum,

containing silicon, nickel, characterized in that it additionally

contains phosphorus and aluminum nitride in the following ratio

components, may. %:

- silicon - 41 ÷ 43

- nickel - 4, l ÷ 5.2

- phosphorus - 0.05 ÷ 0, l

- aluminum nitride - 0.01 ÷ 0.05

- aluminum - the rest.

2. A method of obtaining a powder composite mixture,

including the manufacture of a melt containing aluminum, silicon,

nickel, spray, silicon powder addition, characterized

the fact that upon receipt of the melt additional phosphorus is introduced into it, and

the melt is sprayed with nitrogen at temperature and pressure,

providing the formation of aluminum nitride.