WO2010026794A1

WO2010026794A1 - Magnesium-based composite material having ti particles dispersed therein, and method for production thereof

Info

Publication number: WO2010026794A1
Application number: PCT/JP2009/055027
Authority: WO
Inventors: 勝義近藤; 金子　貫太郎
Original assignee: 株式会社栗本鐵工所
Priority date: 2008-09-03
Filing date: 2009-03-16
Publication date: 2010-03-11
Also published as: CN102016093A; JP2010059481A; EP2327809A1; US20110142710A1; JP4451913B2; KR20100092969A

Abstract

Disclosed is a magnesium-based composite material having Ti particles dispersed therein, which comprises a magnesium matrix and titanium particles dispersed in the magnesium matrix homogeneously. In the composite material, a titanium-aluminum compound layer is formed at the interfaces between the titanium particles dispersed in the magnesium alloy matrix and the matrix.

Description

Ti particle-dispersed magnesium based composite material and method for producing the same

TECHNICAL FIELD The present invention relates to magnesium alloys, and in particular, titanium (Ti) particle-dispersed magnesium-based composites that can be used in a wide range of fields such as home appliances, automobile parts, and aircraft parts by improving both strength and ductility. It relates to a material and a method of manufacturing the same.

Since magnesium (Mg) has the smallest specific gravity among industrial metal materials, it is expected to be used for parts and members such as motorcycles, automobiles and aircrafts, for which there is a strong need for weight reduction. However, since the strength is not sufficient as compared with conventional industrial materials such as steel materials and aluminum alloys, the use of magnesium alloys is currently limited.

In order to solve such problems, development of a composite material in which particles, fibers and the like having characteristics of higher strength and higher hardness than magnesium are dispersed as a second phase has been advanced. Titanium (Ti) is considered as an effective second phase to be dispersed. When comparing stiffness, Mg: 45 GPa, Ti: 105 GPa, and comparing hardness: Mg: 35-45 Hv (Vickers hardness), Ti: 110-120 Hv, titanium particles are dispersed in the magnesium base By doing this, the effect of improving the strength and hardness of the magnesium-based composite material can be expected.

In the conventional composite materials, dispersion of ceramic particles such as oxides, carbides and nitrides and ceramic fibers is the main stream, but these particles and fibers all have high rigidity and hardness, but they have a ductility. Because they are poor, they reduce the ductility (e.g., elongation at break) of the composite itself when dispersed in a magnesium alloy. On the other hand, titanium is a metal, and itself is excellent in ductility, so there is no problem of reducing the ductility of the composite material when titanium particles are added and dispersed in magnesium.

On the other hand, magnesium has a problem that it is inferior in corrosion resistance. This has the characteristic that magnesium is superior, and for example, the standard electrode potential Es (hydrogen H is zero V) is as small as -2.356V. If a small amount of iron (Fe: Es = −0.44 V) or copper (Cu: Es = + 0.34 V) is contained in such magnesium, galvanic corrosion is caused by the potential difference between Mg-Fe and Mg-Cu. The phenomenon progresses. On the other hand, the standard electrode potential of titanium is −1.75 V, and the potential difference with Mg is smaller than that of aluminum (Al: Es = −1.676 V) which is an additive element to Mg. That is, it can be said that the influence on the corrosion phenomenon by dispersing titanium in magnesium is small.

From the above, it is considered effective to use titanium particles as a dispersion reinforcing material in a magnesium base.

As a technology relating to Ti particle-dispersed magnesium composite material that has been reported so far, for example, as Non-Patent Document 1, the Japan Institute of Metals Research Abstract (Mar. 26, 2008) p. 355, no. 464 (Kataoka, Hokusu: Influence of microstructure on mechanical properties of Ti particle-dispersed Mg-based composite material), as Non-Patent Document 2, Proceedings of the Light Metals Society of Japan (May 11, 2008) p. 13, No. 7 (Hokkaido, Kataoka, Komazu: Influence of addition of titanium particles on mechanical properties of magnesium), Non-Patent Document 3 as a summary of powder powder metallurgy lectures (June 6, 2007) p. 148, no. No. 2-51A (Hananami, Fujita, Ohara, Igarashi: Development of magnesium composites by bulk mechanical alloying method), Non-Patent Document 4 as powder and powder metallurgy, Vol. 55, No. 4 (2008), p. 244 (Hananami, Fujita, Motoe, Ohara, Igarashi, Kondo: Development of magnesium composite material by bulk mechanical alloying method), Non-Patent Document 5 as light metal, volume 54, 11 (2004), p. 522-526 (Sato, Watanabe, Miura, Miura: development of titanium particle-dispersed magnesium based functionally graded material by centrifugal solid phase method).

In Non-Patent Document 1 and Non-Patent Document 2, pure titanium particles are dispersed on the surface of a pure magnesium plate and heated and pressed in a state where the pure magnesium plate is placed thereon, the titanium particles are made pure magnesium plate. It is disclosed that a Ti particle dispersed magnesium base composite material in which titanium particles are arranged in a plane direction of a plate is prepared by preparing a composite material in a sandwiched state, and further heating and pressing this composite material in layers. There is.

According to Non-Patent Document 3 and Non-Patent Document 4, after hot-extrusion processing is carried out after continuously applying strong plastic processing while mixing magnesium alloy powder and pure titanium powder and filling in a mold. It is disclosed to produce a Ti particle-dispersed magnesium based composite material.

In any of the above non-patent documents 1 to 4, the heating temperature is set to a temperature sufficiently lower than the melting point of magnesium, and the composite material is manufactured in a complete solid phase temperature range without melting. In the result of the tensile test for each composite material, although the increase of strength of about 5-10% was confirmed compared with the material not adding Ti particles, the ductility (break elongation) is reduced by about 20-30%. . Since magnesium and titanium do not form a compound, the joint interface strength between the two is not sufficient, so that the strength improvement is not sufficient. On the other hand, it is recognized that the interface becomes a stress concentration part and the ductility decreases.

As described above, in order to significantly improve both the strength and the ductility in the titanium particle-dispersed magnesium-based composite material, it is necessary to improve the adhesion at the interface of Mg—Ti.

In Non-Patent Document 5, centrifugal force is applied to a molten metal of magnesium or magnesium alloy (AZ91D) containing titanium particles present as a solid phase, and the difference is caused by the difference in centrifugal force due to the density difference between dispersed particles and molten metal. A manufacturing method is described that uses compositional movement control to control compositional grading. Since the specific gravity of titanium is at least twice the specific gravity of magnesium, it is difficult to uniformly disperse titanium particles in a molten magnesium or magnesium alloy by the centrifugal solid phase method disclosed in Non-Patent Document 5 . In fact, this document states that "It is difficult to disperse titanium particles by this method." Furthermore, in this document, when the titanium particles are introduced into the melt of a magnesium alloy (AZ91D) containing aluminum and the centrifugal solid phase method is applied, the aluminum concentration is extremely high in the titanium particle aggregation portion. And, it is described that a region in which aluminum is solid-solved also exists in the outer peripheral portion of the titanium particles. The reason for this is that, in this document, "the initial melt with high aluminum concentration may have penetrated between the titanium particles by capillary action, and may have been involved in its aggregation and sintering. Thus, the AZ91D alloy containing aluminum The use of the centrifugal solid phase method was found to be problematic in view of the melt composition.

The present invention has been made to solve the above-mentioned problems, and the object of the present invention is to achieve excellent properties by uniformly dispersing titanium particles in a magnesium base and improving the interfacial adhesion between titanium and magnesium. It is an object of the present invention to provide a Ti particle-dispersed magnesium-based composite material having a high strength.

The Ti particle-dispersed magnesium matrix composite material according to the present invention is obtained by uniformly dispersing titanium particles in a magnesium matrix, and titanium-aluminum is formed at the interface between titanium particles dispersed in a magnesium alloy matrix and the matrix. It is characterized by having a compound layer.

In one embodiment, the Ti particle-dispersed magnesium-based composite material is obtained by subjecting a cast material obtained by solidifying a molten metal containing magnesium, aluminum and titanium particles to hot plastic working.

In another embodiment, the Ti particle-dispersed magnesium-based composite material is obtained by machining a cast material obtained by solidifying a molten metal containing magnesium, aluminum and titanium particles into a powder.

In still another embodiment, the Ti particle-dispersed magnesium-based composite material is a powder obtained by solidifying a molten metal containing magnesium, aluminum and titanium particles into a powder by an atomizing method.

In still another embodiment, the Ti particle-dispersed magnesium-based composite material is a sintered and solidified body of a mixed powder of a magnesium alloy powder containing aluminum and titanium particles. In this case, the Ti-particle-dispersed magnesium-based composite material may be obtained by subjecting the sintered and solidified body to hot plastic working.

In one aspect, the method for producing a Ti particle-dispersed magnesium-based composite material according to the present invention comprises the steps of: injecting titanium particles into a melt containing magnesium and aluminum; and uniformly dispersing titanium particles in the melt Stirring the molten metal, and solidifying the molten metal to obtain a composite material having a titanium-aluminum compound layer at an interface between a magnesium base and titanium particles dispersed in the base.

In one embodiment, the step of obtaining the composite material includes solidifying the molten metal to obtain a cast material having a titanium-aluminum compound layer at an interface between a magnesium base and titanium particles dispersed in the base. Applying hot plastic working to the cast material.

In another embodiment, the step of obtaining the composite material comprises solidifying the molten metal to obtain a cast material having a titanium-aluminum compound layer at an interface between a magnesium base and titanium particles dispersed in the base. And machining the cast material into a powder form.

In still another embodiment, the step of obtaining the composite material includes solidifying the molten metal into a powder by atomization.

In another aspect, the method for producing a Ti particle-dispersed magnesium-based composite material according to the present invention comprises the steps of mixing a magnesium alloy powder containing aluminum and titanium particles, and using the mixed powder as the liquid phase generation temperature of the magnesium alloy powder. And holding at a high temperature to sinter and solidify, forming a titanium-aluminum compound layer at the interface between the titanium particles and the base of magnesium.

The manufacturing method according to one embodiment further includes the step of subjecting the sintered body to hot plastic working.

The technical significance or operational effects of the above-described configurations of the present invention will be described in detail in the following items.

It is a figure for evaluating the wettability of the magnesium alloy containing aluminum, and pure titanium. It is the photograph which observed the interface of AZ80 alloy and a titanium board with an energy dispersive analysis scanning electron microscope. It is a figure which shows the analysis result of the interface vicinity of AZ80 alloy and a titanium board. It is the photograph which observed the joining interface of magnesium base and titanium particle. It is a photograph which shows the SEM-EDS analysis result of Ti particle dispersion magnesium base composite material. It is a figure which shows the X-ray-diffraction result showing the production | generation condition of a compound. It is a photograph which shows the SEM-EDS analysis result of Ti particle dispersion magnesium base composite material. It is a photograph which shows the observation result of the tissue inside a billet.

The inventors of the present application have made use of the diffusion phenomenon of aluminum (Al) contained in a Mg alloy in order to develop a titanium particle-dispersed magnesium-based composite material capable of improving the interfacial bonding strength between titanium and magnesium. We focused on the formation of the Ti-Al based compound layer in

(1) Wettability of Magnesium Alloy Containing Al and Pure Titanium The inventors of the present application investigated the wettability of a magnesium alloy droplet containing Al and a pure titanium plate. Specifically, droplets of AZ80 (Mg-8% Al-0.5% Mn) magnesium alloy melted in a high vacuum state (held at 800 ° C.) are made from the nozzle tip made of magnesium oxide (MgO) and the surface of a pure titanium plate Were placed statically, and the wettability between pure Mg and pure Ti at 800 ° C. was evaluated by continuous shooting.

As shown in FIG. 1, the wetting angle at the time of contact with the surface of the Ti plate (t = 0 seconds) was about 118 °, and the wetting angle decreased with the passage of time and reached about 40 ° after 35 minutes. Generally, it is determined that the wetting phenomenon occurs when the wetting angle is less than 90 °, and the wettability improves as the value approaches 0 °. Titanium carbide (TiC), which is said to have good wettability with magnesium, has a wetting angle of about 33 ° at 900 ° C (Reference: A. Contrerasa et al .; Scripta Materialia, 48 (2003) 1625-1630). When considered, the wettability between the AZ80 magnesium alloy containing 8 mass% of the Al component and pure Ti is good.

After the evaluation of the wettability, the interface between the AZ80 alloy and the titanium plate after solidification on the test piece was observed with an energy dispersive analytical scanning electron microscope (SEM-EDS). The results are shown in FIG. A film having a thickness of about 2 μm is formed on the Ti plate side from the bonding interface, and the film has no voids in either of the AZ80 magnesium alloy and the pure Ti plate and has good adhesion. The result of analyzing the vicinity of the interface is shown in FIG.

The above-mentioned film having a thickness of about 2 μm is a layer which is made of a Ti—Al component and which is formed by the reaction of an Al component contained in AZ80 with a Ti plate. By forming such a reaction layer, it is possible to obtain a good adhesion interface having a strong bonding force with both the magnesium alloy side and the Ti particle side.

For comparison, composite materials as reported in the prior art (Non-patent documents 1 to 4), ie, mixed powder of pure titanium powder and pure magnesium powder heated and pressed at solid phase temperature of magnesium powder A composite material was produced, and the bonding interface between the two was observed. The results are shown in FIG. In producing the composite material, the temperature was set to 520 ° C. and set lower than the melting point of pure magnesium (650 ° C.) to obtain a completely solid state. As shown by the arrows, a large number of gaps and voids are observed at the interface between the Ti particles and the Mg base, and it can be seen that the adhesion is not sufficient. Therefore, in the manufacturing method disclosed in the prior art, the adhesion between Mg and Ti is not sufficient because heating and sintering are performed at a solid phase temperature below the melting point of Mg, and as a result, the strength and ductility in the composite material It is thought that no improvement was obtained.

(2) Composite material using Ti particle dispersed Mg-Al molten metal The present inventors based on the above results, in order to improve the interfacial bonding strength between a magnesium base and Ti particles, a magnesium alloy containing an aluminum component Was used as the base material, and the molten magnesium alloy was held at a temperature higher than the melting point of the magnesium alloy, and Ti particles were added thereto. The molten metal was solidified after sufficiently stirring the molten metal so that the titanium particles were uniformly dispersed in the molten metal. In the Ti particle-dispersed magnesium-based composite material produced by such a production method, magnesium and titanium particles constituting the base exhibit titanium at the interface by exhibiting good wettability and reactivity between Al and titanium. It is firmly bonded with excellent interfacial bonding strength by interposing an aluminum compound layer.

A composite material in which titanium particles are uniformly dispersed in a magnesium base can be manufactured by a conventional casting method, die casting method or the like. In addition, the cast materials can be machined such as cutting and crushing to form powders. In the magnesium-based composite powder thus obtained, titanium particles are uniformly dispersed in the matrix of magnesium.

A magnesium-based composite powder in which titanium particles are uniformly dispersed in a magnesium base can also be obtained by solidifying a melt of a Mg—Al alloy in which titanium particles are uniformly dispersed by an atomizing method. The atomizing method is a method of producing powder by injecting high pressure water or high pressure gas to a molten metal flow (spraying method). Also in this case, titanium particles are uniformly dispersed inside the obtained powder, and a Ti—Al based compound layer is formed at the interface between the Ti particles and the magnesium alloy base, and has good interfacial bonding strength. .

As described above, after titanium particles are added to a molten magnesium alloy containing Al component and subjected to sufficient uniform stirring treatment, then a magnesium base composite material is obtained by casting method or die casting method, or titanium particles are made uniform. In any of the direct powdering of the Mg-Al alloy melt dispersed in the metal by the atomizing method, the titanium particles and the magnesium in the base have a void due to the excellent wettability and the high reactivity between Al and Ti. Not bond well with good bonding interface.

After heating a Ti particle-dispersed magnesium-based composite material produced by casting or die casting to a predetermined temperature, the material is subjected to hot plastic working such as hot extrusion, hot rolling, forging, etc. Thus, the grains of the base are refined and the strength of the composite material is further improved.

In addition, Ti particle dispersed magnesium base composite powder manufactured by machining process such as cutting from cast material, or Ti particle dispersed magnesium base composite powder obtained by injecting high pressure water or high pressure gas to molten metal flow is compacted and solidified. Powdered compacts and sintered / solidified bodies are prepared, and if necessary, the composite powders are joined together metallurgically by subjecting them to hot plastic working such as hot extrusion, hot rolling, forging etc. Alternatively, it is possible to create a sintered Ti particle-dispersed magnesium-based composite material.

In the above embodiment, titanium particles of an appropriate amount were charged into the molten Mg-Al alloy, but as another embodiment, it is also possible to obtain a Ti particle-dispersed magnesium based composite material by the following method is there. In this embodiment, a magnesium alloy powder containing aluminum and titanium particles are mixed, and the mixed powder is held at a predetermined temperature to sinter and solidify. The important thing here is to keep the mixed powder at a temperature higher than the liquid phase generation temperature of the magnesium alloy powder. By holding at such a high temperature, in the sintered and solidified body after sintering, the magnesium and titanium particles constituting the base intervene the titanium-aluminum compound layer at the interface, and good wettability and It is strongly bonded with excellent interfacial bonding strength. The strength of the composite material is further improved by subjecting the sintered and solidified body to hot plastic working.

In each of the above-described embodiments, the titanium-aluminum compound layer formed at the interface between magnesium and titanium particles constituting the base body may completely surround the titanium particles, or the surface of the titanium particles It may be partially covered.

Prepare AZ61 (Mg-5.9% Al-1.1% Zn) magnesium alloy block and titanium powder with an average particle size of 29.8 μm as starting materials, and heat the magnesium alloy block to 700 ° C in a carbon crucible In the molten metal, 5 mass% of the above-mentioned titanium particles were added in the total weight ratio. Thereafter, in order to prevent segregation of titanium particles and settling to the bottom, the molten metal was sufficiently uniformly stirred for 30 minutes, and then the molten material was cast into a water-cooled mold to produce a cast material.

The results of SEM-EDS analysis of the obtained cast material are shown in FIG. It is recognized that there is no void at the interface between the titanium particles and the substrate, and that it has good adhesion. Further, as a result of elemental analysis, it can be seen that the aluminum (Al) component is present in the form of layers on the surface of the titanium particles, and a Ti—Al compound layer is formed at the interface between the titanium particles and the AZ61 base. Good adhesion between the titanium particles and the substrate is obtained by this reaction layer.

In addition, when titanium powder was added to the molten metal and uniform stirring was performed, X-ray diffraction was performed on the composite material in the case where the processing time was 10 minutes, and the formation state of the compound was observed. The results are shown in FIG.

When the uniform stirring treatment is performed for 30 minutes, the diffraction peak of the Al ₃ Ti intermetallic compound is detected, but the peak of the above compound is not detected in the stirring treatment material for 10 minutes. That is, when the stirring time is not sufficient, the diffusion reaction between the Al component in the magnesium alloy and the titanium particles does not proceed, as a result, it becomes difficult to form the Ti—Al compound layer which is the feature of the present invention. Therefore, it is desirable that the uniform stirring process be performed for 30 minutes or more after the titanium particles are charged into the molten magnesium alloy.

Pure magnesium powder and Al-Mn alloy powder were prepared, and the two powders were blended so as to have an AZ61 alloy composition (Mg-6% Al-1% Zn) as a whole. The mixed powder was compacted and solidified by a hydraulic press, and the molded and solidified body was charged into a carbon crucible and heated and held at 700 ° C. to produce a molten AZ61 magnesium alloy. The titanium particles described above were added to the molten metal so that the total weight ratio was 10 mass%. Thereafter, in order to prevent segregation of titanium particles and settling to the bottom, the molten metal was uniformly stirred for 30 minutes, and then the molten material was cast into a water-cooled mold to produce a cast material.

The results of SEM-EDS analysis of the obtained cast material are shown in FIG. Although 10 mass% of titanium particles were added, no remarkable aggregation / segregation structure of the particles was observed, and it was observed that the titanium particles were uniformly dispersed in the substrate. Further, it can be seen that there is no void at the interface between the titanium particles and the base material, and that it has good adhesion. Furthermore, as a result of elemental analysis, it can be seen that the aluminum (Al) component exists in a layer form so as to surround the surface of the titanium particles, and that a Ti—Al compound layer is formed at the interface between the titanium particles and the AZ61 base. Good adhesion between the titanium particles and the substrate is obtained by this reaction layer.

A bulk sample of AZ91D magnesium alloy (Mg-9.1% Al-1.1% Zn-0.2% Mn) and titanium powder with an average particle diameter of 29.8 μm are prepared as starting materials, and AZ91D magnesium alloy ingot is prepared. Were melted by heating to 720 ° C. in a carbon crucible, and 3 mass% of the above-mentioned titanium particles were added to the molten metal in a total weight ratio. After that, the molten metal was uniformly stirred for 40 minutes to prevent segregation of the titanium particles and settling to the bottom, and then cast into a cylindrical mold to prepare a billet having a diameter of 60 mm.

The result of observing the tissue inside the billet is shown in FIG. In the base, fine Mg ₁₇ Al ₁₂ compounds (β phase) are uniformly dispersed, and titanium particles are also uniformly dispersed in the base without aggregation and segregation.

A billet for extrusion with a diameter of 45 mm is produced by machining from the above-described Ti particle-dispersed AZ91D cast billet, and the billet is heated and held at 350 ° C. for 5 minutes in an argon gas atmosphere, and hot extrusion processing immediately (extrusion ratio: 37) ) To produce a round bar extruded material with a diameter of 7 mm. The tensile test piece was extract | collected from the obtained extruded material, and the tensile test was done at normal temperature.

As a comparison, an AZ91D magnesium cast billet without addition of titanium particles was produced under the same conditions as above, and a billet for extrusion with a diameter of 45 mm was similarly produced by machining and subjected to extrusion. The tensile test was similarly performed on the obtained extruded material at normal temperature. The tensile test results are shown in Table 1.

The tensile strength and yield strength of the AZ91D cast billet extruded material to which 3 mass% of titanium particles are added are significantly increased as compared with the material obtained by extruding the AZ91D cast billet containing no titanium particles, and on the other hand, the elongation at break There is no major decline. Further, in the Ti particle-dispersed AZ91D composite material according to the present invention, the formation of TiAl ₃ intermetallic compound is confirmed from the result of X-ray diffraction, and there is no void at the titanium particle / AZ91D base interface, and a good bonding interface is formed.

From the above results, in the Ti particle-dispersed Mg-Al based composite material according to the present invention, a Ti-Al based compound is formed on the surface of the titanium particles without aggregation / segregation of the titanium particles, The bonding strength between the titanium particles and the base is improved, and as a result, the strength of the magnesium-based composite material can be improved.

Note that, even when a Ti particle-dispersed magnesium-based composite material is manufactured using Ti-6Al-4V alloy powder (average particle diameter: 22.8 μm) having higher hardness instead of titanium particles, titanium alloy particles are aggregated and It is uniformly dispersed in the base without segregation, and the formation of a TiAl ₃ intermetallic compound is confirmed at the interface between the titanium alloy powder and the AZ91D base, and there is no void at the interface, and a good bonding state Was found to have The tensile strength in the case of adding 3 mass% of Ti-6Al-4V alloy powder is 414 MPa, and it is possible to confirm the increase in strength more than the composite material in which 3 mass% of pure titanium particles are added. Thus, the hardness and strength of the titanium particles dispersed in the magnesium alloy base are further increased, so that the strength of the magnesium composite is further improved.

A chip with a total length of about 1 to 4 mm is produced from this Ti particle-dispersed AZ91D cast billet by cutting, this chip is filled in a SKD11 die, and a pressing force of 600 MPa is applied by a hydraulic press to make a 45 mm diameter powder. A molded billet was produced. The green compact billet was heated and held at 350 ° C. for 5 minutes in an argon gas atmosphere, and immediately subjected to hot extrusion (extrusion ratio: 37) to produce a round bar extruded material with a diameter of 7 mm. The tensile test piece was extract | collected from the obtained extruded material, and the tensile test was done at normal temperature.

As a comparison, an AZ91D magnesium cast billet to which titanium particles were not added was produced under the same conditions as above, and similarly, chips having a total length of about 1 to 4 mm were produced by cutting. After mixing 3 mass% of titanium particles in this AZ91D cutting powder and performing mixing processing for 1 hour with a dry ball mill, the mixed powder is compacted with a hydraulic press in the same manner as above, and passed through a 350 ° C. heating process It was extruded. The tensile test was similarly performed on the obtained extruded material at normal temperature. The tensile test results are shown in Table 2.

In the comparative material, since the heating temperature was as low as 350 ° C., the Al component contained in AZ91D did not react with the titanium particles, and as a result, no Ti—Al based compound was formed on the surface of the titanium particles. As a result, a sufficiently high bonding strength can not be obtained at the interface between the titanium particles and the base material, and as a result, both the tensile strength and the yield strength decrease compared to the strength characteristics of the extruded material of only AZ91D shown in Example 3. And the elongation at break also decreased.

On the other hand, in the extruded material produced from the Ti particle-dispersed AZ91D composite powder according to the present invention, in the same manner as the inventive example shown in Example 3, an AZ91D cast billet not containing titanium particles is compared with the extruded material. The tensile strength and the yield strength are significantly increased, while the breaking elongation is not significantly reduced. Further, in the Ti particle-dispersed AZ91D composite material according to the present invention, the formation of TiAl ₃ intermetallic compound is confirmed from the result of X-ray diffraction, and the titanium particle and the AZ91D base form an excellent bonding interface with no voids at the interface. doing.

From the above results, in the Ti particle-dispersed Mg—Al based composite material according to the present invention, a Ti—Al based compound is formed on the surface of the titanium particles without aggregation / segregation of the titanium particles, and titanium The bonding strength between the particles and the base is improved, and as a result, the strength of the magnesium-based composite material can be improved.

Although the embodiments of the present invention have been described above with reference to the drawings, the present invention is not limited to the illustrated embodiments. Various modifications and variations can be made to the illustrated embodiment within the same or equivalent scope of the present invention.

The present invention can be advantageously used as a Ti particle-dispersed magnesium-based composite material having excellent strength and a method for producing the same.

Claims

In a Ti particle-dispersed magnesium-based composite material in which titanium particles are uniformly dispersed in a magnesium matrix,
A titanium-particle-dispersed magnesium-based composite material comprising a titanium-aluminum compound layer at an interface between the titanium particles dispersed in the magnesium alloy matrix and the matrix.
The Ti particles according to claim 1, wherein the Ti particle-dispersed magnesium-based composite material is obtained by subjecting a cast material obtained by solidifying a molten metal containing magnesium, aluminum and titanium particles to hot plastic working. Dispersed magnesium based composites.
The Ti particles according to claim 1, wherein the Ti particle-dispersed magnesium-based composite material is obtained by machining a cast material obtained by solidifying a molten metal containing magnesium, aluminum and titanium particles into a powder. Dispersed magnesium based composites.
The Ti particle dispersed magnesium based composite material according to claim 1, wherein the Ti particle dispersed magnesium based composite material is a powder obtained by solidifying a molten metal containing magnesium, aluminum and titanium particles into a powder form by an atomizing method.
The Ti particle dispersed magnesium based composite material according to claim 1, wherein the Ti particle dispersed magnesium based composite material is a sintered and solidified body of a mixed powder of a magnesium alloy powder containing aluminum and a titanium particle.
The Ti particle dispersed magnesium based composite material according to claim 5, wherein the Ti particle dispersed magnesium based composite material is obtained by subjecting the sintered and solidified body to a hot plastic working.
Charging titanium particles into a molten metal containing magnesium and aluminum;
Stirring the melt such that the titanium particles are uniformly dispersed in the melt;
A method of producing a Ti particle-dispersed magnesium based composite material, comprising the steps of: solidifying the molten metal to obtain a composite material having a titanium-aluminum compound layer at an interface between a magnesium base and titanium particles dispersed in the base. .
The step of obtaining the composite material includes solidifying the molten metal to obtain a cast material having a titanium-aluminum compound layer at an interface between a magnesium base and titanium particles dispersed in the base, and the cast material 8. A method of manufacturing a Ti particle-dispersed magnesium-based composite material according to claim 7, comprising: performing hot plastic working.
The step of obtaining the composite material includes solidifying the molten metal to obtain a cast material having a titanium-aluminum compound layer at an interface between a magnesium base and titanium particles dispersed in the base, and the cast material 8. A method of manufacturing a Ti particle-dispersed magnesium based composite material according to claim 7, further comprising: machining to a powder form.
The method for producing a Ti particle-dispersed magnesium-based composite material according to claim 7, wherein the step of obtaining the composite material includes solidifying the molten metal into a powder by atomization.
Mixing a magnesium alloy powder containing aluminum and titanium particles;
And Sintering and solidifying the mixed powder at a temperature higher than the liquid phase generation temperature of the magnesium alloy powder, and forming a titanium-aluminum compound layer at the interface between the titanium particles and the base of magnesium. Method of manufacturing Ti particle dispersed magnesium based composite material.
The method for producing a Ti particle-dispersed magnesium based composite material according to claim 11, further comprising the step of subjecting the sintered body to hot plastic working.