JPS60223654A - Insert-casting method of different metal - Google Patents

Abstract

PURPOSE:To improve bonding strength by providing a coating layer formed by bonding fine metallic powder having a prescribed grain size by a resin binder on the surface of a metal to be insert-cast then performing insert-casting thereby sintering and joining the fine metallic powder to both metals at the boundary. CONSTITUTION:The fine metallic powder having <=10mu average grain size is bonded with the resin binder and a paste or sheet-shaped material is prepd. The surface of a metallic member 1 to be insert-cast is coated with said material to form the coating layer 2. The melt of a metal different from said member 1 is cast on the surface of the layer 2, by which both metals are insert-cast and united to one body.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a method of encasing a certain metal member with dissimilar metals, and more specifically, a casting method that can increase the bonding strength of both metals when encasing. It is related to.

(Prior Art) For mechanical parts and the like, it is often convenient to use a composite member in which a member made of one metal is joined to a member made of another metal, since the features of both metals can be effectively utilized. For example, a metal with high hardness is bonded to the surface of a metal with high strength and toughness to form a member with high wear resistance without reducing the toughness and strength. In addition, instead of joining members made of different metals, it has conventionally been possible to sinter metal powder that has a predetermined function such as wear resistance on a metal base to form a sintered layer that has a predetermined function. It has been known. An example of forming such a composite member is disclosed in Japanese Patent Publication No. 53-19540, in which a sheet containing a metal powder with a high melting point and a sheet containing a metal powder with a low melting point are used. A method is disclosed in which a sintered layer is formed by polymerizing a sheet and heating and sintering the same.

Furthermore, the casting method is also often used as a method for making composite members. For example, when making an engine rocker arm, the base is made of aluminum alloy to reduce inertial mass, and a tip of iron-based material is bonded to the part that contacts the cam to improve wear resistance. In this case, chips made of iron-based materials may be cast in aluminum alloy.

However, since the wettability of aluminum to iron-based materials is not very good, it is usually difficult to achieve good bonding between the two, and there is a problem that the bond strength is often weak.

(Object of the Invention) The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a casting method that can bond dissimilar metals with poor wettability even when the castings are made of dissimilar metals. This is the purpose.

In addition, the present invention is based on the fact that the sintering start point, which is one of the physical properties of metal/metal fine powder made of extremely fine metal particles with a particle size of 10 μm or less, is extremely low compared to the original sintering start temperature. The purpose of this invention is to provide a method that uses this fine metal powder to cast dissimilar metals with poor wettability with sufficient bonding strength.

(Structure of the Invention) The casting method of the present invention involves bonding fine metal powder with a resin binder to create a paste-like or sheet-like substance, and coating the surface of the wave-preventing casting metal to form a coating layer. This method is characterized in that a molten metal of a different metal is cast onto the surface of the wave-preventing encased metal covered with this coating layer, and the two are integrated as a cast.

(Effects of the Invention) According to the present invention, a coating layer made of fine metal powder bonded with a resin binder is provided on the surface of the wave-preventing filled metal, and then it is cast. It can be sintered and bonded to both the casting and wave-preventing metal to strengthen the bond between the two metals. In addition, this effect will be even greater if a recently developed ultrafine metal powder consisting of extremely fine metal particles with a particle diameter of 1.0 μm or less is used.

(Example) The present invention will be explained below with reference to Examples.

FIG. 1 shows one embodiment of the present invention, and is a sectional view showing a part of a rocker arm. A wear-resistant iron chip 1 is placed at the end of the rocker arm in contact with the cam, and this is cast from the aluminum alloy that forms the base 3 of the rocker arm. In order to provide a strong bonding force, the chip 1 is provided with a protrusion 1b having the shape shown in the figure on the side opposite to the contact surface 1a with the cam, and an aluminum base 3 is formed to cover the protrusion 1b.

To manufacture this rocker arm, first, the surface of the chip 1 to be mounted on is covered with a paste or sheet-like substance made of fine powder such as Ni bound with a resin binder to form a coating layer 2. The rocker arm is formed by covering the coating layer 2 with molten aluminum alloy. In this way, the molten aluminum alloy penetrates into the coating layer 2,
By alloying with the heat of the molten metal, both the aluminum alloy and the chip 1 are metallurgically bonded, so that the bonding force between the two is strengthened.

Next, this bonding force will be explained using a specific experimental example.

95% by weight of Cu fine powder with an average particle size of 7 μm and 5% by weight of an acrylic binder were kneaded with toluene, rolled into a sheet with a thickness of 1.5 shoes, and then the sintered material (
5.8% by weight of Cr, Pl.

1% by weight, MO4.2% by weight, C1.8% by weight, SiO
, 6% by weight, remaining Fe composition, density 7.65g/α3)
A 30 μm thick sheet of acrylic binder was used to adhere to one side of the acrylic binder. Next, this was heated at 5°C/in nitrogen gas.
The temperature was raised to 300℃ at a heating rate of 1 minute, and the temperature remained at this temperature for 6
After holding this for 0 minutes, it was slowly cooled to room temperature. This sample was placed in a molten metal forging mold for testing with a diameter of 50 mm x 100 M.
Aluminum alloy (Cu2.5% by weight, Si9.2% by weight, f
vlo, 1% by weight, Fed, 8% by weight, Mn 0.2% by weight, Ni 0.1% by weight, sno, i% by weight, balance A9.
) was injected and molten metal forging was performed.

95% by weight of ultrafine Ni powder with an average particle size of 0.08 μm and 5% by weight of an acrylic resin binder are kneaded with toluene to form a paste, and this is mixed into a paste (5.8% by weight of Cr). %, Pl
, 1% by weight, Mo4.2% by weight, C1.8% by weight, Si
Density 7.65g/c with composition of 0.6% by weight and remaining 1”e
m3), heated to 300°C at a rate of 5°C/min in a nitrogen gas atmosphere, held at this temperature for 60 minutes, and then slowly cooled to room temperature. At this time, the coating thickness of the paste-like crosstalk material was set to an average of 0, 35#.

This sample was placed in a molten metal forging mold of φ50s x 100m for testing, and aluminum alloy (Cu2.5 heavy assembly% 1, Si9.2
Weight%, MOo, 1% by weight, Fed.

Molten metal forging was performed using 8% by weight of Mn, 0.2% by weight of Mn, and 0.1% by weight of Ni.

The structure of the joint at this time is shown in Figure 2, and as can be seen from this figure, the joint was completely joined. This figure is a micrograph showing a 100x magnification of a cut joint that has been corroded with a 5% sodium hydroxide aqueous solution. The rough grained part on the bottom is aluminum alloy. The bonding strength at this time is 12
~16/(9f/s2) The bonding strength of this bond was 22 to 27K9 f/ms, and it was in the state of almost metal bonding.

As explained above, according to the method of the present invention, for example, Fe
Even when the wettability of both materials is poor, such as when a material is cast with aluminum, a sufficiently strong bonding force can be obtained.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a rocker arm cast according to the present invention, and FIG. 2 is an enlarged cross-sectional photograph showing the cast-clad interface of a member cast according to the present invention. 1... Chip 2... Covering layer 3... Base wX1
Figure 0 II2 Diagram (Voluntary) Procedure Nefusho 1. Display of the case Japanese Patent Application No. 59-79554 2, Title of the invention Method for casting dissimilar metals 3, Person making the amendment Relationship to the case Patent applicant Address 3-1 Shinchi, Fuchu-cho, Aki-gun, Hiroshima Name Mazda Stock Company [May 15, 1980 Name change process (all at once)] 4, Agent 5-2-1-6 Roppongi, Minato-ku, Tokyo Number of inventions increased by amendment None 1) Specification, page 6 Correct line 9 rcuJ to "N1". 2) On page 7, line 6, ``95'' is corrected to ``150''. 3) Correct "5" in line 7 of the same page to "50". 4) "At this time" in the third line of page 8 is corrected to "Experiment Example 1J. Procedural Amendment Sliding Type To the Commissioner of the Patent Office, August 23, 1980, Patent Application 1982-7
9554 No. 2, Title of the invention: Method for casting dissimilar metals 3, Relationship with the case of the person making the amendment Patent applicant address: 3-1 Shinchi, Fuchu-cho, Aki-gun, Hiroshima Prefecture Name: Mazda Motor Corporation 4, Agent: Port of Tokyo 5-2-1 Roppongi, Ward

Claims (3)

[Claims] (1) A coating layer of a paste-like or sheet-like substance made of fine metal powder bonded with a resin binder is formed on the surface of the wave-preventing covered metal member, and the main surface of this coating layer is coated with the cast-covered metal member. is a casting method for dissimilar metals, which is characterized by casting melts of different metals and integrating the two. (2) The method for casting dissimilar metals according to claim 1, wherein the average particle size of the metal fine powder is 10 μm or less. (3) The method for casting dissimilar metals according to claim 1, wherein the metal fine powder is ultrafine powder with an average particle size of 1.0 μm or less.