JPS6352105B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thermal sprayed ceramic coated metal body with improved impact resistance, scratch resistance, and abrasion resistance.
Materials for base coating and ceramic coating,
By specifying the coating thickness, the aim is to improve both the adhesion (impact resistance) and abrasion resistance of the coating.

It is often desirable for iron-based metal products to have improved properties such as impact strength, scratch resistance, and abrasion resistance, depending on their use. For example, the iron head of a golf club, along with the ball, may be exposed to grass, sand, etc.
Since it may hit soil etc., it is required to improve surface properties such as scratch resistance and abrasion resistance in addition to impact resistance strength. For example, in order to improve the surface characteristics of the iron head of a golf club,
It has been proposed to form a base metal sprayed layer and a ceramic sprayed layer on a metal substrate such as iron, and then impregnate and harden it with a liquid synthetic resin.
-34537). That is, in this technique, the porosity of the base metal and the ceramic sprayed layer is utilized to serve as an anchoring layer for the resin coating of these sprayed layers. However, some disadvantages have been found in such techniques for improving surface properties using coatings. The first problem is that the coating layer peels off when a strong impact is applied. The second problem is that the abrasion resistance of the resin coating is not necessarily good, and the characteristics of the metal may be diminished. Therefore, even if resin coating is used, it should be kept to the minimum required from the viewpoint of rust prevention, etc., depending on the selection of the base metal.

The main purpose of this invention is to improve the surface characteristics such as scratch resistance and abrasion resistance while making the best use of the characteristics of the metal substrate, and to have a coating layer with good adhesion (and therefore impact resistance). An object of the present invention is to provide a ceramic-coated metal body.

According to the research conducted by the present inventors, a ceramic sprayed film of a specific composition is coated on a metal substrate such as an iron-based material through a specific base metal layer, and the total thickness of the coating layer is set to a specific extremely thin layer. It has been found that increasing the thickness is extremely effective in achieving the above objectives.

The ceramic-coated metal body of the present invention is based on such knowledge, and more specifically, the ceramic-coated metal body of the present invention is based on a Ni-Cr alloy sprayed coating on an iron-based metal base, and
A ceramic sprayed film consisting of 40 to 86% by weight of Cr ₃ C ₂ and 60 to 14% by weight of TiO ₂ is sequentially formed, and the total thickness of the sprayed film is 20 to 200 μm. .

That is, in the ceramic-coated metal body of the present invention, the base coating layer formed on the metal base, such as iron, is made of a Ni-Cr alloy that has good adhesion to the base metal and has excellent corrosion resistance. and that the ceramic sprayed layer thereon is made of a combination of Cr ₃ C ₂ , which retains its metallic properties and has good adhesion to the Ni-Cr alloy, and TiO ₂ , which has good wear resistance. In addition, the total thickness of the coating is said to be 20 to 200 μm, which provides good adhesion to the substrate, so overall the adhesion (and therefore impact resistance) is excellent without impairing the metallic properties of the substrate. A ceramic coated metal body with excellent wear resistance is provided.

This invention will be explained in more detail below. In the following descriptions, "%" and "parts" represent quantitative ratios.
are based on weight unless otherwise specified.

As the base metal of the ceramic-coated metal body of the present invention, iron-based metals, titanium-based metals, and the like are preferably used. Preferred specific examples include stainless steel (SUS304, etc.) and structural steel (SS30, etc.).

The necessary parts of such a metal base to be coated, for example, the ball hitting surface of the head face of an iron club and at least its downward extension that contacts the ground,
First, a base thermal spray coating of Ni-Cr alloy is formed. this
The Ni-Cr alloy base thermal spray coating improves the adhesion of the entire coating layer and also slightly contributes to improving the corrosion resistance. A material mainly composed of Ni is preferably used. Although this Ni--Cr undercoating sprayed film exhibits its effects even if it is relatively thin, it is preferably formed to a thickness of 5 to 20 μm.

Note that the head face surface other than the above-mentioned areas requiring coating is often buffed if the base is made of stainless steel, but if it is made of steel such as SS30, hard chrome plating is generally performed.

Next, on the Ni-Cr base spray coating, substantially
_Cr3C2 40~86 _% , preferably 50~70%, _TiO2 60~
Form a ceramic sprayed film with a composition of 14%, preferably 50-30%, and make the total thickness of the sprayed film 20-30%.
200 μm, particularly preferably 60 to 100 μm.
Cr ₃ C ₂ is effective in providing good adhesion to the Ni-Cr alloy, which is presumed to be due to residual metallic properties as mentioned above.
If it is less than %, good adhesion cannot be provided;
When added in excess of 86%, the wear resistance of the coating layer decreases. On the other hand, TiO ₂ is effective in improving the abrasion resistance of the ceramic coating layer, but if it is less than 14%, the effect is poor, and if it is used in excess of 60%, the adhesion of the coating layer will decrease. If the total thickness of the sprayed layer is less than 20 μm, a rough surface will remain on the surface of the sprayed layer, resulting in a lack of wear resistance and durability of the coating layer, and the impact damping ability due to the porosity of the sprayed layer will decrease. Put it away.
On the other hand, if the total thickness of the sprayed layer exceeds 200 μm, stress increases due to the difference in thermal expansion between the sprayed layer and the substrate, resulting in insufficient adhesion strength and impact resistance.

Thermal spraying of base coating layer and ceramic coating layer is
It can be carried out by ordinary plasma spraying, and it is preferable to use argon-He as the plasma carrier gas to prevent oxidation or nitridation of the sprayed material and form a sprayed layer with good adhesion. In order to improve the properties of the substrate,
The particle size of the thermal spraying material, which is preferably preheated to about 100 to 150°C before thermal spraying, is in the range of 1 to 15 μm for the base Ni-Cr alloy, and 1 to 10 μm for Cr ₃ C ₂ and TiO ₂ powder. is preferably used.

The sprayed layer obtained on the substrate in this way is generally porous, so if the substrate is rust-prone like SS30, a resin such as polyurethane resin or epoxy resin is applied to a thickness of 5 to 30 μm. It is preferable to apply the coating to improve corrosion resistance.

As described above, according to the present invention, a mixture of Cr ₃ C ₂ and TiO ₂ is used as the ceramic spraying material when coating a base metal such as iron with ceramic spraying through a Ni-Cr spraying base layer. , and by limiting the total thickness of the sprayed layer to a relatively thin range of 20 to 200 μm, the characteristics of the metal substrate are utilized as much as possible while improving surface properties such as scratch resistance, abrasion resistance, and impact attenuation ability. However, a ceramic-coated metal body having a coating layer with good adhesion (and therefore impact resistance) is provided. The ceramic-coated metal body of the present invention is generally suitably used for iron-based metal products that require scratch resistance, abrasion resistance, and impact resistance, in addition to iron heads of golf clubs.

Hereinafter, this invention will be explained in more detail with reference to Examples and Comparative Examples.

Example 1 Each base material made of SUS304 and SS30 is
While heating to 150℃, a Ni-Cr alloy with a composition of 20% Cr and the balance of Ni (average grain size approximately 10 μm) is sprayed with Argon-He plasma using a plasma gun (manufactured by Metco) at an input of 40 V and 800 A. and about
A sprayed layer with a thickness of 15 μm was formed.

Then, Cr ₃ C ₂ contents of 20, 30, 40, 60, 80, and 100% by volume were applied to the undercoat substrate, respectively.
(28, 40, 51, 70, 86, 100% by weight)
Cr ₃ C ₂ −TiO ₂ composite thermal spray powder (average particle size approximately 5μ),
Sprayed under the same plasma spraying conditions as above to a thickness of approx.
A ceramic coating layer of 25 μm was formed, making the total thickness of the coating layer 40 μm.

Next, the end face of a 25 mm diameter iron rod was adhered to the surface of these sprayed films using epoxy resin, and the rod was pulled in the axial direction to measure the tension required to break the sprayed film.

The measurement results are shown in Figure 1.

Separately, under the same thermal spray coating conditions as above, SUS304
Ni-Cr _base layer and _Cr3C2
The sprayed layer was formed to a total thickness of 40 μm, and a golf club (No. 7) equipped with this head was
The ball was struck 300 times at a speed of 40 m/sec into sand grains of 1 mm in diameter, and the remaining film thickness at the most worn area (the position of the sweet spot on the standard ball hitting surface) was measured. The measurement results are also shown in FIG.

Looking at the results in FIG. 1, it can be seen that when the Cr ₃ C ₂ content in the Cr ₃ C ₂ -TiO ₂ coating layer is in the range of 30 to 80 volume %, especially 40 to 60 volume %, the adhesion ( It can be seen that the coating layer has good tensile strength) and abrasion resistance (residual film thickness).

Example 2 In the same manner as in Example 1, a Ni-Cr base layer with a thickness of 15 μm was formed on SUS304 and SS30 substrates, and a composite thermal sprayed material containing 40% by volume of Cr ₃ C ₂ (average grain (diameter of about 5 μm) was thermally sprayed under the same conditions as in Example 1 to form a thermally sprayed coating layer with a total thickness of 20 to 300 μm, and the tensile strength was measured in the same manner as in Example 1. As a result, the measurement results shown in FIG. 2 were obtained.

The results in FIG. 2 show that as the sprayed layer thickness (particularly the ceramic sprayed layer thickness) increases, the adhesion (tensile strength) of the coating decreases.

Example 3 In the same manner as in Example 2, when using SUS304 base material, the thickness of the ceramic sprayed layer was changed and the total thickness of the sprayed layer was 20 to 65 μm. depth) was measured. The results are shown in FIG.

The results shown in FIG. 3 show that when the sprayed layer thickness is too small, large irregularities exist on the coating surface.

Example 4 In order to see the effect of the Ni-Cr underlayer, a 15 μm thick Ni-Cr underlayer was formed on the SUS304 substrate in Example 2, and TiO ₂ containing 40% by volume of Cr ₃ C ₂ was added on top of the Ni-Cr underlayer with a thickness of 15 μm.
−Cr ₃ C ₂ composite spray coating layer, total thickness 20~300μm
In contrast to the example in which Ni was formed to a thickness of
Except for the -Cr base layer, only the TiO ₂ -Cr ₃ C ₂ composite thermal spray coating layer was formed, and the tensile strength was measured in the same manner as in Example 1. The measurement results are shown in FIG. 4 together with those of Example 2.

According to Figure 4, if there is no Ni-Cr underlayer,
It can be seen that the tensile strength (and therefore the adhesion of the sprayed layer) decreases as the coating thickness increases. This is thought to be due to the increase in stress at the interface, and Ni
It is understood that the -Cr underlayer has the properties of a metal base and a thermal spray material, and plays the role of stress relaxation.

Furthermore, when we conducted a test of hitting the above two types of coating layers with a hammer after red heat as a simple method according to JIS, we found that when there was no base layer, peeling occurred after several treatments at a thickness of about 40 μm, but Ni - When a Cr underlayer was provided, no peeling occurred even after 20 treatments.

[Brief explanation of drawings]

FIG. 1 to FIG. 4 are graphs showing the characteristics evaluation results of thermal spray coating layers according to Examples and Comparative Examples,
Figure 1 shows the dependence of adhesion (tensile strength) and abrasion resistance (residual film thickness) on the Cr ₃ C ₂ content in ceramic sprayed materials, and Figures 2 and 4 show the dependence of adhesion (tensile strength) on the Cr 3 C 2 content. FIG. 3 shows the dependence of surface roughness on the coating layer thickness.

Claims (1)

[Claims] 1 Ni-Cr alloy thermal spray coating and
1. A ceramic-coated metal body formed by forming a ceramic sprayed film consisting of 40 to 86% by weight of Cr ₃ C ₂ and 60 to 14% by weight of TiO ₂ , wherein the total thickness of the sprayed film is 20 to 200 μm.