JPS62130205A - Sintering method for powder alloy sheet - Google Patents

Abstract

PURPOSE:To sinter a powder alloy sheet after easily and exactly making a positioning operation of the powder alloy sheet to be adhered to the sintering and bonding surface of a metallic base body by positioning the above-mentioned powder alloy sheet with a powder metallic sheet as a reference, then positioning said sheet. CONSTITUTION:The powder alloy sheet 1 formed by kneading a wear resistance powder alloy and binder, the metallic base body 2 consisting of a ferrous metal, etc., and the powder metallic sheet 3 for positioning having the same size as the size of the sintering and bonding surface A are prepd. The sheet 3 is then adhered to the center of the sheet 1, i.e., except an allowance S for shrinkage in the sintering stage thereof, by using an adhesive agent (I, II), and thereafter the sheet 3 is fitted and adhered to the surface A of the base body 2. After the sheet 1 is thereby adhered to the base body 2, a sintered layer 4 is formed by sintering under prescribed conditions (V). The effect is remarkable particularly when the surface of the metallic base body is curved according to the method of this invention.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention provides a method for forming a wear-resistant sintered layer on the surface of a metal substrate by sintering a powder alloy sheet adhered to the surface of the metal substrate. The present invention relates to a method for sintering a powder alloy sheet made of powder.

(Prior art) One of the methods for forming wear resistance on the surface of a metal substrate is to adhere a wear resistant powder alloy sheet to the surface of the metal substrate and heat and sinter it to create a wear resistant sintered layer. It is known to form a
9540, JP-A-59-83704)
.

That is, a powder alloy sheet formed by kneading a wear-resistant powder alloy and an adhesive is prepared, and after adhering this powder alloy sheet to a location where wear resistance is required on a metal base, the sintering temperature is This process forms a wear-resistant sintered layer on the metal substrate.

Therefore, as a prerequisite for forming a wear-resistant sintered layer at a desired location on a metal substrate, it is necessary to accurately adhere the powder alloy sheet to the desired location.

(Problems to be Solved by the Invention) However, when this type of method is used, there is a problem in that it is difficult to align the powder alloy sheet when adhering it to a desired location on a metal base.

In other words, since the dimensions of the powder alloy sheet take into account shrinkage due to sintering, it is difficult in practice to accurately align the powder alloy sheet to the location where wear resistance is required on the metal base.
In particular, when the surface of the metal substrate is curved, the difficulty increases significantly.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a method for sintering a powder alloy sheet that facilitates alignment when adhering the powder alloy sheet to a desired location on a metal substrate.

(Means and effects for solving the problem) In order to achieve the above-mentioned technical problem, the present invention, in addition to the above-mentioned powder alloy sheet, uses a metal base having the same dimensions as the part where wear resistance is required. A powder metal sheet for positioning is prepared, and this powder metal sheet for positioning is used as a reference when adhering the powder alloy sheet to a metal base.

That is, the present invention involves bonding a powder alloy sheet formed by kneading a wear-resistant powder alloy and an adhesive to a sintered bonding surface of a metal base, and heating and sintering the sheet in a non-oxidizing atmosphere. Based on the premise of a sintering method for powder alloy sorting that forms a wear-resistant sintered layer on the surface of a metal substrate, a powder alloy that can be alloyed with the wear-resistant powder alloy is kneaded with an adhesive. , prepare a positioning powder metal sheet having the same dimensions as the sintered joint surface of the metal base, and bonding the positioning powder metal sheet to the powder alloy sheet; The present invention is characterized in that the powder alloy sheet is bonded to the sintered bonding surface of the metal base through a metal substrate.

With this configuration, when bonding the powder metal sheet to the sintered bonding surface of the metal base, the powder metal sheet for positioning, which has the same dimensions as the sintered bonding surface, can be simply aligned with the sintered bonding surface. , the powder alloy sheet will be misaligned.

(Example of Man 1) Figure 1 shows that by adhering a powder alloy sheet to a metal base and sintering it, 1IIFt is applied to the surface of the metal base.
3 shows a process for forming an abradable sintered layer.

To explain each process with reference to the same figure, first, a powder alloy sheet 1 with dimensions that take into account shrinkage during sintering is aligned with a metal base 2 that has the same dimensions as the sintered bonding surface A. Prepare a powder metal sheet 3 for alignment, and use an adhesive (not shown) to place the alignment powder metal sheet 3 in the center of the powder alloy sheet 1, in other words, by adjusting the shrinkage allowance S during sintering.
As shown in FIGS. 1 (I) and (II)), FIGS. 1 (III) and (IV), the powder metal sheet 3 for positioning is attached to the sintered bonding surface A of the metal base 2 while leaving the adhesive. The powder alloy sheet 1 is adhered to the metal base 2 by adhering with the above-mentioned adhesive in accordance with the above conditions, and is then sintered under predetermined conditions to form a sintered layer 4 (see Fig. 1). (See V).

This will be explained in more detail below.

The Kuramasa base metal base 2 is made of iron-based metal, and is formed into a cube as a test piece, on which an abrasive sintered layer is formed on one end surface. One end surface of this metal base 2, that is, the sintered bonding surface A is 17 mm long and 15 mm wide.
It has dimensions of mm.

powder alloy sheet Powder alloy sheet 1 contains C1.8% by weight, PI.

0% by weight, MO4, 2% by weight, Cr: 8.1% by weight, balance Fe, 95% by volume of wear-resistant eutectic powder alloy consisting of a powder particle size of 150 mesh or less, and diluted with a solvent such as toluene as an adhesive. After kneading 5% by volume of acrylic resin, it is made into a slurry and poured onto a mold covered with template paper.
After evaporating the solvent, it is passed through a rolling roll to a density of 4.
．． 6g/'Cm3. A sheet formed into a sheet having a thickness of 1.5 mm is used. Its dimensions are 20 mm long and 18 mm wide in anticipation of shrinkage during sintering.

P combines with Fe and C to form a phosphorus eutectic, which serves to improve wear resistance and lower the melting point. In other words, it goes without saying that the alloy powder of the powder alloy sheet 1 needs to have wear resistance when heated and sintered, but since the adhesiveness of acrylic resin adhesive has a temperature limit, This is because it is preferable that the freezing temperature be as low as possible.

If P is less than 0.5% by weight, the liquid phase amount will be less than 10% by volume, making it impossible to bond to the base material. Moreover, if it exceeds 2.5% by weight, the phosphorus eutectic will crystallize in a net shape, significantly reducing the toughness. Therefore, it is preferable that P is in the range of 0.5 to 2.5% by weight.

Next, C combines with Fe and P to strengthen the matrix and form a hard phase, and also forms a phosphorus eutectic, which is useful for increasing density and bonding with the base material.

If C is less than 1.5% by weight, the formation of low melting point crystallized substances will be small, resulting in an increase in density and insufficient bonding with the base material. Also,
If it exceeds 4.0% by weight, the amount of liquid phase that crystallizes becomes too large, making it impossible to maintain the required shape, and at the same time, the carbides crystallize in a net shape and the crystal grains become coarse, resulting in a decrease in toughness. Therefore, it is preferable that C is in the range of 1.5 to 4.0% by weight.

Mo is a necessary element that strengthens the matrix and forms a hard phase, and also combines with Fe and C to lower the melting point. If it is less than 2.5% by weight, the hard phase will decrease. Furthermore, since the amount of liquid phase is reduced, the density does not increase, and as a result, wear resistance decreases and joining becomes difficult. If it exceeds 10.5% by weight, the amount of liquid phase will be too large, resulting in brittleness and significantly reduced toughness. Therefore, M
Preferably, o is in the range of 2.5 to 10.5% by weight.

Cr is a secondary element that improves strength and wear resistance,
In addition, ■ and W are valid. These elements strengthen the base,
It is particularly useful for improving toughness and is a preferable element because it combines with carbon to form a hard phase, but if it exceeds 10% by weight, the above effects become saturated and it is economically unfavorable.

Next, B, Si, Ni, and Mn may be added as other elements. B is an element that combines with Fe and C to form a hard phase and lowers the melting point. If it is less than % by weight, the ternary eutectic of Fe-B-C decreases, so frf#
Abrasion resistance and seizure resistance deteriorate. If it exceeds 3.0% by weight, it becomes very brittle and is not practical. Therefore, it is preferable that B be in the range of 0.5 to 3.0% by weight.

The role of Si is to improve the fluidity of the molten metal during the production of alloy powder, and also to improve the wettability with the base metal during bonding.If it exceeds 5.0% by weight, hardness decreases and wear resistance increases. I miss sex.

Ni is an element that is useful for strengthening the base, but if it exceeds 5.0% by weight, the role of the hard phase decreases, making it easy to cause seizure.

In addition, since Mn also has the same function as Ni,
It is preferably added in an amount of 5.0% by weight or less.

Particle size of the powder metal Also, a of the powder metal contained in the powder alloy sheet l
There is a factor that greatly affects the porosity of the sintered phase.
It is preferable to set it as 150 men or less. Particle size is 1
When the mesh size exceeds 50, the porosity increases accordingly, impairing the wear resistance of the sintered phase.

Blending ratio of adhesive and powder alloy The blending ratio of the acrylic resin used as the adhesive and the powder alloy is preferably 3 to 15% by volume of the adhesive and the balance being the alloy powder.

If the amount of adhesive is less than 3% by volume, the adhesiveness will be insufficient and the powder alloy sheet will become brittle, making it impossible to secure the necessary flexibility of the sheet. In this case, the resin content becomes excessive, which adversely affects the porosity and the like, and at the same time, it becomes impossible to bond to the base material.

Powder metal bending sheet for positioning It is basically the same as the powder alloy sheet 1 described above.

However, it is preferable that the powder metal sheet 3 for positioning is sintered at the same or lower sintering temperature than the powder alloy sheet 1. From this, the powder metal sheet 3 for positioning contains 2% by weight of C2, 3% by weight of Pl, and M o 5
, 3% by weight of Cr, 1.0% by weight of Cr, balance Fe, and 90% by volume of a powder alloy consisting of a powder particle size of 250 or less, and 10% by volume of an acrylic resin diluted with a solvent such as toluene as an adhesive were kneaded and rolled. A sheet molded into a sheet having a thickness of 0.3 mm is used.

That is, the proportions of C, P, and MO are higher than those of the powder alloy sheet 1, and a more lateral metal powder is used to increase the surface area for activation. The dimensions of the sintered bonding surface A of the metal base 2 are
It is said to be 17mm long and 15mm wide, which is the same.

Thickness of powder metallurgical sheet for positioning The powder metallurgical sheet for positioning 3 is preferably 71V higher than the powder alloy sheet 1 . That is, it is preferable that the thickness of the powder alloy sheet l is 0.5 mm or less. If the thickness exceeds 0.5 mm, a step will occur in the sintered alloy layer 4,
The cost required for processing increases, making it uneconomical, and it also becomes difficult to easily alloy, that is, integrate with the powder alloy sheet 1.

Adhesive The adhesive used to bond the main components of the adhesive powder alloy sheet 1, the metal base 2, and the alignment powder metal sheet 3 is an adhesive made of the same acrylic resin as the adhesive for reasons that will be detailed later. .

Sintering conditions N2. The following heating conditions are used in an inert gas atmosphere such as Ar, a reducing atmosphere such as H2, and a non-oxidizing atmosphere such as a vacuum atmosphere.

Heating conditions Cp Temperature increase rate 1°C/min → 300°C ■ 300°C x 60 minutes ■ Temperature increase rate 10°C/min → 1100'0 +4+ l l OO°C x 30 minutes slow cooling Under the above heating conditions, ■ The heating rate shown in is 40'0
/min or less is preferable. This temperature increase rate is 40°
If the temperature exceeds C/min, the low boiling point content in the adhesive and the acrylic resin as the pressure-sensitive adhesive will rapidly volatilize, which may damage the powder alloy sheet or cause bubbles to form on the adhesive surface and cause it to fall off.

Moreover, it is preferable that the heating temperature in the above (2) be 150 to 380°C. More preferably it is 200-350°C. At temperatures below 150°C, the amount of undecomposed acrylic resin increases, and rapid decomposition occurs when heated above 380°C, and the amount of tar pitch-like substances produced by acrylic resin is small, making it difficult to bond at high temperatures. There is a possibility that the strength becomes low and the powder alloy sheet 1 falls off. On the other hand, 380°
This is because if the temperature exceeds C, the acrylic resin will rapidly decompose, and the amount of tar pitch-like substances that contribute to adhesion will be small, resulting in the possibility that the powder alloy sheet will fall off. and,
The reason why the heating and holding time in step 1 was set at 60 minutes was to obtain a sufficient amount of the above-mentioned tar pitch-like substance.Of course, the optimal time varies depending on the heating temperature, but if it is less than 5 minutes, the tar pitch-like substance will be generated. The amount of pitch-like material produced is small, resulting in insufficient adhesion, and heating for more than 120 minutes is not economical.

Surface 1 FIG. 2 shows a guide jig 10 used when adhering the alignment powder metal sheet 3 to the powder alloy sheet 1.

The guide jig 10 has a box shape with the same dimensions as the powder alloy sheet 1, and the guide jig 10 is intended to cover the shrinkage allowance S.
By applying this in advance, adhesion of the alignment powder metal sheet 3 is facilitated.

A number of experiments were carried out under the above conditions and good results were obtained in all of them. That is, the displacement of the sintered alloy layer formed on the specific portion (sintered bonding surface A) of the metal base 2 was extremely slight, and no problem was obtained in practical use.

(Second Example) Explanation of the same conditions as in the above example will be omitted,
Characteristic parts of this embodiment will be explained below.

The powder alloy sheet 1 had the same composition as in the first embodiment and was used after being formed into a size of 25 mm in length, 20 mm in width, and 2.0 mm in thickness.

On the other hand, the powder metal sheet 3 for alignment contains C4.0% by weight, P2.0% by weight, Mo9, 0% by weight, Cr3
．． 93% by volume of a powder alloy consisting of 0% by weight, the balance being Fe, and a powder particle size of 200 or less, and 7% by volume of an acrylic resin as an adhesive diluted with toluene were kneaded and processed to a thickness of 0.0% by volume.
The 2 mm sheet was cut into 21 mm long and 16 mm wide pieces, which are the same dimensions as the sintered bonding surface A of the metal base 2, and used.

The sintering temperature conditions are: ■ Temperature increase rate io℃/min → 300℃ (300℃ x 60 minutes! 3) Increase IQr II degree 1℃/min - 1080'C 4
．． ) lO80°C x 30 minutes L5) Slow cooling In this example as well, good results were obtained in all cases.

(Third Embodiment) In this embodiment, the adhesion of the powder alloy sheet 1, the metal base 2, and the alignment powder metal sheet 3 is performed by magnetic force. Other conditions that are the same as those in the first and second embodiments will not be described, and the differences will be described below.

powder alloy sheet Powder alloy sheet 1 contains C2.0% by weight and Pl.

2% by weight, Mo5, 0% by weight, Cr8.0% by weight
, powder alloy 95 consisting of powder grain size of 150 or less with balance Fe
% by volume and 5% by volume of acrylic resin diluted with toluene etc.
The material was kneaded and rolled to form a sheet with a thickness of 1.5 mm, which was then cut into 20 mm long and 18 mm wide sheets for use.

Powdered metal sheet for positioning The powdered metal sheet for positioning 3 is made of C
95% by volume of a powder alloy consisting of 1.1% by weight of Cr, 5.0% by weight of Cr, balance Fe, powder particle size of 150 or less, and 5% by volume of acrylic resin diluted with toluene etc. were kneaded and rolled to a thickness of 0.1mm. The sheet was cut into 17 mm in length and 15 mm in width, which are the same dimensions as the sintered bonding surface A of metal base 2, and used.

Adhesion was achieved by the magnetic force of the positioning powder metal sheet 3.

Sintering temperature (D heating rate 10°C/min → 300°C (Q) 300 ”C3
00°C x 30 minutes (slow cooling) Good results were obtained in all cases in this example. Also, since no acrylic resin adhesive was used in this example, gas generation during sintering was reduced. This has the advantage that there is no risk of defects occurring in the sintered layer.Of course, the magnetic metal contained in the alignment powder metal sheet 3 is as follows:
In addition, W steel, Crjg, W-Cr steel, Com, etc. may be used.

Although the present invention has been described in detail above, the present invention is not limited thereto and includes the following modifications.

(1) In order to prevent defects such as dents and bulges in the sintered layer 4 due to gases caused by the volatilization of adhesives and adhesives during sintering, powder alloy sheet) 1 is 0.2 to 0.4 A gas venting hole having a diameter of approximately mm may be provided to vent gas.

(2) Alternatively, powder alloy sheet 1, powder metal sheet for positioning 3. Gas venting grooves may be provided on the surface of the Kinku base body 2.

(3) Furthermore, when an adhesive is used, the gas vent groove may be filled with the adhesive.

This has the advantage that the adhesive can be easily quantified. In this case, the kinematic viscosity of the adhesive is preferably 3.5 to 8.0 cst. If the kinematic viscosity is less than 3.5 cst, the adhesive strength will be insufficient. 8.0cs
If it exceeds t, the flow of the adhesive will deteriorate, making it difficult to fill the gas vent groove.

(Effects of the Invention) As is clear from the above description, according to the present invention, since the powder metal sheet can be aligned using the powder metal sheet for alignment as a reference, the alignment work can be performed easily and accurately. can be done. Particularly, when the surface of the metal substrate is curved, the effect is significant.

[Brief explanation of drawings]

Fig. 1 is a process diagram of a method for sintering a powder alloy sheet according to an embodiment, and Fig. 2 is an explanatory diagram illustrating a guide jig that facilitates the bonding work of powder metal sheets for positioning and its work. . l: Powder alloy sheet 2 Two metal substrates 3: Powder metal sheet for positioning A: Sintered bonding surface of metal substrate S: Shrinkage allowance (H) due to sintering of powder alloy sheet
(II) (IV) Figure (IID

Claims (1)

[Claims] (1) A powder alloy sheet formed by kneading a wear-resistant powder alloy and an adhesive is adhered to the sintered bonding surface of a metal base, and heated and sintered in a non-oxidizing atmosphere. In a method for sintering a powder alloy sheet that forms a wear-resistant sintered layer on the surface of a substrate, the sheet is formed by kneading a powder metal that can be alloyed with the wear-resistant powder alloy and an adhesive, and Prepare a powder metal sheet for positioning with the same dimensions as the bonding surface, and after adhering the powder metal sheet for positioning to the powder alloy sheet, apply the powder metal sheet to the powder metal sheet for positioning through the powder metal sheet for positioning. A method for sintering a powder alloy sheet, comprising: adhering the sheet to a sintered bonding surface of the metal substrate.