JPS6240339A - Aluminum-base composite material excellent in cutting tool life - Google Patents

Abstract

PURPOSE:To obtain an Al-base composite material combining prescribed high elasticity and heat-resisting strength with superior cutting tool life by uniformly dispersing nonmetallic grains having controlled size and quantity in an Al matrix. CONSTITUTION:The nonmetallic grains are uniformly dispersed in the Al matrix. Moreover, the above nonmetallic grains are set as in the following: average grain size, <=3.0mum; maximum grain size, <=8.0mum; and content, <=35.0vol%, preferably >=about 1.5%. In this way, the Al-base composite material combining high elasticity and heat-resisting strength with superior cutting tool life characteristic can be obtained. The above composite material can be manufactured by blending, in a prescribed ratio, an Al powder with a powder of nonmetallic reinforcing material having prescribed average and maximum grain sizes, such as SiC, Al2O3, Si3N4, B4C, etc., mixing the above by a mechanical alloying method etc., compacting the resulting mixture into a billet and then subjecting the billet to extrusion forming.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention is applicable to connecting rods, pistons, rocker arms, piston pins, torsion bars, etc., which require good cutting tool life characteristics in addition to high elasticity and high heat-resistant strength. The present invention relates to an aluminum matrix composite material that is suitable as a material for automobile engine parts and has an excellent cutting tool life.

In this specification, the term "aluminum" is used to include aluminum alloys.

Conventional Technology and Aluminum-based Composite materials generally have excellent elasticity and heat-resistant strength, so they are suitable as materials for automobile engine parts, etc. However, in actual application, these parts are However, aluminum-based composite materials generally have poor machinability, especially the life of cutting tools, which hinders their practical application as materials for automobile engine parts. This was a contributing factor.

This invention was made in view of such circumstances, and
The object of the present invention is to provide an aluminum matrix composite material that has a predetermined high elasticity and has an improved cutting tool life.

Means for Solving the Problems As a result of experiments and research by the inventors, the purpose was to create a particle dispersion-strengthened aluminum material in which non-metallic particles with a roughly controlled content m were uniformly dispersed in an aluminum matrix. This was achieved using a base composite material.

That is, the present invention provides an aluminum matrix composite material in which nonmetallic particles are uniformly dispersed in an aluminum matrix, wherein the nonmetallic particles have an average particle size of 3.0 μm or less,
Maximum particle size: 8.0 μm or less, content 1:35. Ovo 1
% or less and has an excellent cutting tool life.

The nonmetallic particles form the reinforcing phase of the composite material, and examples of nonmetallic particles include SiC, Aj! z
Known non-metallic reinforcements in metal matrix composites are optionally employed, including 03, Si3N4.84C, etc. By dispersing these nonmetallic particles in a matrix, the properties of a composite material are exhibited.
In this invention, the average particle size, maximum particle size, and content must be controlled to be below the above specified values. This is because if the above value is exceeded, there is no effect of improving the life of the cutting tool, and the intended purpose cannot be achieved. In order to expect a more significant improvement effect on cutting tool life, the average particle size of the particles should be 1.
It is preferable to set it to 0 μm or less. Note that experimentally it seems possible to have a size of about 0.005 μm. Further, the maximum particle size is preferably 5.0 μm or less,
The content is preferably 25VO1% or less. However, if the content is less than 1% OVO, the desired high elasticity may not be obtained, so it is desirable to set it to 1.0% VOI% or more.

On the other hand, the composition of aluminum as the 71-RIX material is not particularly limited, and any aluminum selected depending on the required characteristics of the applied parts can be used.

Therefore, not only pure aluminum and conventional standard alloys, but also alloys in which the blending ratio of each component is set arbitrarily may be used.

This aluminum material must be prepared as a powder for composite manufacturing.

The aluminum matrix composite material according to the present invention is not limited in any way to the VB6 method, and any known manufacturing method for dispersion-strengthened composite materials may be arbitrarily adopted. To give an example of a manufacturing method, after mixing a nonmetallic powder consisting of particles with an average particle size and a maximum particle size that meet the requirements of the present invention and aluminum powder at a content ratio below the above-mentioned specified conditions, vacuum hot pressing etc. Pressure molded into a billet for extrusion,
Next, there is a method of manufacturing by extrusion molding this billet. In addition, in order to disperse the nonmetallic particles more uniformly in the aluminum matrix, a so-called mechanical alloying process (mechanical alloying method) in which the nonmetallic powder is mechanically dispersed in the aluminum powder is used at the mixing stage of both powders. It is also recommended to produce a composite material by making a composite powder and then sequentially applying pressure molding and extrusion molding.

Effects of the Invention The aluminum matrix composite material according to the present invention does not impair the high elasticity and heat resistance strength due to being a composite material, and as is clear from consideration of the examples, the aluminum matrix composite material does not suffer from cutting, which is a drawback of aluminum matrix composite materials. This greatly improves tool life. Therefore, even when applied to materials such as automobile engine parts, the parts can be cut well, and the range of practical use as materials for various parts can be expanded.

Example Next, examples of the present invention will be shown in comparison with comparative examples.

Al-8wt%Fe-5,5wt%s;-4.5wt%
An aluminum alloy having a composition of Cu-O and 5 wt% Mg was pulverized to a particle size of 150 mesh or less by N2 gas atomization. Next, this aluminum alloy powder and various nonmetallic powders consisting of particles having the average particle size and maximum particle size shown in Table 1 were mixed so that the mass m was about 2 Kq and the content of the nonmetallic powder was as shown in the same table. The mixture was mixed using a Henschel mixer (high-speed stirrer) until the mixture was mixed. Mixing conditions are atmosphere: N
The test was carried out using 2 gases, rotation speed: 200 rpm, and time: 4 minutes.

Table 1 (Left space below L) Next, all samples except Samples No. 006 and 7 were subjected to mechanical alloying treatment using an attritor to produce mechanically alloyed powders. The processing conditions were: atmosphere: Ar gas, dispersion aid: ethanol, rotation speed: 280 ml), and processing time: 10 hours.

Next, the composite powder obtained above and sample N006.
For No. 7, the mixed powder that was not subjected to mechanical alloying treatment was collected into a container with an Ar gas atmosphere after each treatment, and then transferred to a vacuum hot press machine and hot pressed to form a billet with an outer diameter of 75 mm and a length of 150 mm. was created. Hot pressing involves transferring powder from a container to a container for powder compaction in an Ar atmosphere device, then evacuating the device using a rotary pump, then heating it to 400'C with a heater installed in the container to 5,000 degrees Celsius. -7000KC
The pressure was lf/rm.

Next, the billet obtained in 1 was heated to 400° C. and extruded into a round bar with an outer diameter of 23.7 mm using an extruder 10. The tempering was set to T1.

The cutting tool life of the various composite materials thus obtained was investigated. In addition, the mechanical properties of sample No. 1.3.10.11 at room temperature and 300'C were investigated. The results are shown in Table 2.

In addition, the cutting tool life is determined by cutting speed: 247 m/min.
, feed: 0.2 mm/rpm, depth of cut: 1 mm, test material □ of outer diameter 23 mm x length 200 mm was cut into 8
Evaluation was made based on the wear width of the 1□ side surface of a 10 carbide cutting tool after cutting twice. 1 [Space below] 1 □ Table 2, 5! 2 Seal ■ Wanren Light T ■ Goka (Note) σ8: Tensile strength E: Elastic modulus δ: Elongation.

As is clear from the above results, the aluminum matrix composite material according to the present invention has high elasticity and high strength, and the side flank wear width of the cutting tool is 200 μm in both cases.
It was confirmed that there were no practical problems and that the cutting tool had an excellent lifespan. Also, from the results of mechanical properties,
It can be seen that the finer the particle size of the nonmetal particles, the better the strength and elongation.

that's all

Claims (1)

[Claims] An aluminum matrix composite material in which nonmetallic particles are uniformly dispersed in an aluminum matrix, wherein the nonmetallic particles have an average particle size of 3.0 μm or less and a maximum particle size of 8.0 μm.
The following is an aluminum matrix composite material having an excellent cutting tool life and having a content of 35.0 vol% or less.