JPS62158842A - Sliding material - Google Patents

Abstract

PURPOSE:To provide a sliding material with excellent seizure-resisting properties such as high thermal conductivity, high melting point, high strength, etc., by dispersing trace amounts of grain-size-regulated wear-resistant grains into an Ni- and Si-containing copper alloy having a specific composition. CONSTITUTION:The wear-resistant grains with 0.3-80mu diameter are dispersed by 0.001-0.8wt% into the copper alloy containing Ni and Si in the 2:1 atomic % ratio and in an amount of 1.0-12wt%, in total, and having the balance essentially Cu with usual impurities. The wear-resistant grains are selected from borides, silicides, nitrides, oxidic or carbidic ceramics, etc. This sliding material has high hardness and is excellent in seizure-resisting properties as compared with the existing materials.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an aging precipitation type copper alloy that is used in sliding members that rotate or reciprocate and has high thermal conductivity, melting point, and high strength. This invention relates to a sliding material made of a composite material with abrasive particles.

Conventional sliding materials include special high-strength brass and lead bronze materials specified in JI8.

Recently, as an improved version of these,
There are No. 3422 and Special Publication No. 53-44135.

Problems to be Solved by the Invention However, these conventional sliding materials have the following drawbacks.

That is, the elements Zn, 8B, and At are CtL
Because of the large amount added to (1) the thermal conductivity is very low compared to Cμ (2)
The melting point is 100°C to 300°C lower than that of CtL. (3) The hardness of intermetallic compounds formed by third elements such as Mn, 8i, Pa, and Ni makes them suitable for sliding materials used under ultra-high loads. is not enough.

An excellent characteristic of sliding materials is high thermal conductivity (
2] The melting point is high. (3) The dispersed particles of the matrix (1) have high hardness and are uniformly dispersed.

Purpose of the Invention The present invention has been made in view of the above circumstances, and has high thermal conductivity, high melting point, and high strength, and has markedly superior seizure resistance compared to existing high-performance sliding materials. The purpose is to provide sliding materials.

Means and operation for solving interlayer points In order to achieve the above object, the present invention provides Ni and 8
A wear-resistant material with a diameter of 0.3 to F30μ is contained in a copper alloy containing i at a ratio of 2:1 in a total amount of 1.0 to 12'N, and the remainder substantially consisting of copper and ordinary impurities. Sexual particles 0.001~
It is composed of 0.81i% dispersed.

Example Hereinafter, the present invention will be explained with reference to the drawings.

A sintering method is available as a method for uniformly dispersing hard particles as wear-resistant particles in a Cu-Ni-8i matrix, but there are limitations in terms of cost, strength, etc., and this is not necessarily suitable. Additionally, if hard particles are physically added during alloy melting,
In many cases, problems tend to occur, such as particles floating due to the difference in specific gravity, or problems such as the molten metal and particles not being mixed at all due to poor wetting between the two.

As a result of various studies on this point, the inventors attempted to uniformly disperse the hard particles using the following means.

■ Each of the elements constituting the hard particles is individually added to the molten metal to newly generate the desired hard particles in the molten metal.

■ The molten metal and hard particles are vigorously stirred and mixed uniformly by arc melting, and then rapidly solidified.

It has been found that, according to method (■) above, the problem of wettability between the particles and the molten metal is eliminated, and even if the specific gravity of the hard particles produced is quite different from the specific gravity of the molten metal, the degree to which these particles float or settle is small. Ta.

If the added elements (often two types) are both easily soluble in the melt, the probability that these elements will combine in the molten metal is small. Moreover, if the amount added is large, depending on the element, the thermal conductivity of the alloy will be greatly reduced.

If none of the 10,000 added elements dissolves in KCμ, the probability that these elements added in the form of powder or the like will meet and bond in the molten metal will be low.

From the above, it is necessary that one of the hard particle-forming elements dissolves in the Cμ molten metal, and that the remaining element either hardly dissolves in the Cμ molten metal or does not dissolve at all. As a combination of elements that satisfy these conditions, MO, B (M (forms l t Bs) I W, B (%
Bs is formed) Mo, 8i (MOSit is formed) IC
r, 5i (forming Cr8i1), etc. Especially M
Adding elements such as O and W that do not dissolve in Cw at all to the molten metal T
When this happens, some of these tend to aggregate in a pure metal state and become residual T.

In order to prevent these, 1) Add powders such as MO and W in a uniformly mixed state with a large amount of Cu powder to prevent clumping.

+1) It is effective to add it in the form of a solid solution such as a Ni-Mo alloy.

Next, the method (2) above will be explained.

The basic idea is to rapidly solidify a molten metal to which ceramic powder has been added while vigorously stirring it, thereby preventing the floatation and separation of low-density ceramic powder.

In order to solidify the molten metal rapidly, it is necessary to bring the molten metal into contact with a metal having high thermal conductivity immediately after stopping stirring. For this purpose, there is no time to take the molten metal into a ladle and cast it into a mold. Therefore, the melting process must be carried out in a mold with high thermal conductivity. Such melting is possible only by arc melting, and in particular, only the direct arc melting method in which electricity is applied directly to the melted material can stir the molten metal vigorously.

Based on the above, the inventor considered melting the material in an argon arc furnace having a water-cooled copper mold as a specific means for achieving the objective.

In addition, it is also possible to build up these steel alloy ceramic composite materials on a metal base material using a TJG welder or the like.

The alloys produced by the methods (1) and (2) above were maintained at around 900° C. to about IH and then cooled with water to form a solution. After this 5
Aging treatment at 00°C XIH was performed to obtain the desired high hardness.

The present invention will be explained in detail below.

Example ■ We considered mixing ceramic particles during melting in an argon arc furnace.

As a matrix alloy, the atomic ratio of Ni and Si is 2:1.
A Cg-Ni-Si gold alloy was used. By aging treatment after solution treatment, Ni and 9i precipitate and the entire alloy is hardened. The composition is Cu-2N&! 8*(wtl)
And so.

As a ceramic powder, the average diameter gμ is s i C1, which is also 80μ, sio, which is also 20μ, and 0. Also, taking the same <30μ si, o, 0.019~Q
, 3 wt% was added.

A mixture of metal Si, Ni ingots, electric steel ingots, and electrolytic copper powder with an average diameter of about 80μ and the above ceramic powder was inserted into a mixing mold of an argon arc furnace, and
The dissolution was performed by 0 people.

The ingot weight is 100F.

After melting, the ingot was cut at the center and the distribution of ceramic powder was observed. As a result, the distribution was extremely uniform for all ingots. It is thought that the fact that the matrix alloy has high thermal conductivity and solidification progressed sufficiently quickly also contributed greatly.

Note that if the ceramic powder is mixed with the copper powder and only the ceramic powder is added, the ceramic powder will charge up and scatter during melting.

Therefore, the same effect can be expected by applying electroless Ni plating to ceramic powder.

After solution treatment at 8900°C x 11 (→ water cooling), aging treatment at 500°C x IH was performed, hardness was measured, and the material was subjected to a sliding test.

The test conditions are shown in Table 1.
This is a type in which two test pieces of a+X20 are slid against a mating plate of φ130 that rotates once.

Table 1 The results of the sliding test conditions and above are summarized and shown in Table 2 and FIG. 1 together with the results of the comparative example.

No matter which ceramic powder is added, the pvmasg value is improved compared to the one without additive (Comparative Example 2), especially for those with a diameter of 20μ. The product with around 3wt% of O* added has T-glue.

Regarding 8iC, as shown in Figure 1, when the amount of addition exceeds Q, ) wtl, the p vmax is higher than the level of existing special high strength brass.
It can be seen that the value decreases. This is because 8iC has particularly high hardness, and as the amount of addition increases, the effect of hitting the mating plate increases, leading to heat generation on the sliding surface. On the other hand, s
io has the lowest hardness, and even when added up to 0.8 wt@, the PVmas value below T can be maintained.

Note that A 40B 1m particles also have high hardness, but since the particle size is 20 μm, which is larger than SiC, the number of particles does not increase much even if a relatively large amount is added.

Because of this, the probability of hitting the opponent's board became smaller, resulting in a better result. This tendency is consistent with 30μ si, N
The same would apply to those to which 4 powders were added.

Table 2 Example of Pvmax value and hardness of ceramic powder mixed lumber
,, 8iB,, W, B,, CrB,, Mo,
B., VSit.

For the purpose of producing hard particles of M o SL t, alloys shown in Table 3 to which these constituent elements were added singly were produced. It was subjected to solution treatment and aging treatment at 900° C.XIH and 500° C.

For convenience, melting was carried out in the same argon arc furnace as in the examples. Among the added elements, only W and MO, which do not dissolve at all in CtL, were added in the form of powder with a diameter of 2 to 3 s.

The results are also listed in the right column of Table 3.

Table 3: Properties of materials produced during dissolution of hard particles As a result of light microscopic observation, uniform dispersion of hard particles was observed in all alloys.

Although the hardness of the particles could not be measured, the scratches characteristic of hard particles were produced in parallel to the polishing direction after puff polishing on the polished surfaces of all alloys, suggesting the generation of particles with sufficient hardness. Furthermore, since the hot water is vigorously stirred by the arc,
Pure W, pure MO, etc. did not remain in a lump.

It can be seen from Table 3 that the results of the sliding test are far superior to the T comparative example shown in Table 1 for all alloys. 124~
25 alloy has a high hardness due to its large Ni and 9i contents, and it has a high p'imax due to micro uneven contact and T.
The value has decreased slightly.

Example 0 In Example 2, particles having a relatively high pvmax value, advantageous in terms of cost, and having a small difference in specific gravity from the Cμ molten metal were used: W, B, , MO, B, and MO! 98
I picked up 1. 59 was dissolved in the atmosphere, the ingot was slowly cooled and solidified, and the non-uniformity of particle distribution was checked, followed by solution treatment, aging treatment, hardness measurement, and sliding test.

The melting was carried out by crucible melting using a graphite crucible at a melting temperature of 1250°C.

After the electric steel burn-through, the surface of the molten metal was coated with a charcoal-based covering agent, and after deoxidizing with 0.02% P, hard particle constituent elements were added. 5~(Ni and Cμm 15% after Qmin
After adding the Si master alloy and holding it at 5 mil, the crucible was taken out of the heating furnace and solidified.

The alloy composition, the addition method of hard particle constituent elements, and the results of the sliding test are summarized in Table 4.Those containing T and B were added using commercially available pure B crystals.

MO and W can be added by uniformly mixing powder with a diameter of 2 to 3μ with 100 times the weight ratio of electrolytic copper powder (average diameter FEOμ), or in the case of MO, add Ni-5Mo mother powder separately melted. It was added in the form of an alloy. The Ni-Mo master alloy was melted in an argon arc furnace, but since the amount used in one melting is small, the cost does not increase even when mass production is considered.

Table 4 Manufacturing method and pvmGx value of slowly cooled solidified material after atmospheric melting Next, MO and B for alloys 26 to 33 in Table 4.

The relationship between the amount of dispersion and the PVmax value is illustrated in FIG. 2. Even dispersion of Mez B6 particles with only O-000-0O1 was found to be more effective than that without any additives, with 0
．． When it reaches 4% of 002w, T exceeds the level of existing high performance materials. This effect can be achieved with a much smaller amount of dispersion compared to the one in Figure 1, because MO and W are added in the form of fine powder, and the average diameter of the hard particles is also 0.3~0.
This is because the particles become as fine as 3μ and the number of particles dispersed increases significantly. The particle size of the hard particles was confirmed correctly using an electron microscope replica method.

Next, reasons for limiting the particle diameters of Ni, f3i, hard particles, and the amount of dispersion of hard particles will be described.

Niff1si If Ni, Si is less than 1 vyt%, hardly any improvement in hardness is observed even after aging treatment. Also 12W
If it exceeds f%, it becomes extremely brittle and causes problems such as cracking during sliding. Thermal conductivity also decreases significantly.

Preferably it is 1.5-5w4%.

The dispersion effect is recognized from the particle size of hard particles of about 0.3 μm (alloys 426 to 35). The upper limit is 80μ (see Figure 1), and if it exceeds 80μ, the particles will sink into the mating plate, increasing the friction coefficient and causing the sliding part to generate heat, PV77! This leads to a decrease in α2 value. 7, preferably 1 to 30 J.

It can be seen from FIGS. 1 and 2 that the dispersion amount of hard particles from o, oo+ to o, swtts is effective. Preferably 0.002 to 0.4
wt'lA.

Effects of the Invention As detailed above, the present invention provides Ni and 8i with 2=
1 atomic chill, a total of 1.0 to 12% by weight is contained in the copper alloy, the remainder consisting essentially of copper and ordinary impurities.
．． This is a sliding material made by dispersing 0.001 to 0.8% by weight of wear-resistant particles of 3 to 30 μm.

Therefore, the sliding material according to the present invention has high thermal conductivity, high melting point, and high strength, and has significantly higher seizure resistance than existing high-performance sliding materials.

[Brief explanation of drawings]

Figure 1 is a diagram of the relationship between the amount of hard particles added and the PVmax value,
FIG. 2 is a diagram showing the relationship between the amount of hard particles dispersed and the p'imax value. Figure 1 Addition of particles! [wtX] Figure 2

Claims (4)

[Claims] (1) Ni and Si in an atomic % ratio of 2:1, totaling 1.
0.001 to 0.8% by weight of wear-resistant particles with a diameter of 0.3 to 80μ are dispersed in a copper alloy containing 0 to 12% by weight, with the remainder consisting essentially of copper and ordinary impurities. Materials for dynamic use. (2) The sliding material according to claim (1), wherein the wear-resistant particles are boride. (3) The sliding material according to claim (1), wherein the wear-resistant particles are silicide. (4) The sliding material according to claim (1), wherein the wear-resistant particles are nitride-based, oxide-based, or carbide-based ceramics.