JPH05230621A - Method for vapor-depositing subliming metal containing cr and its alloy - Google Patents

Abstract

PURPOSE:To provide the method by which the generation of splashes can be suppressed at the time of vapor-depositing subliming metal contg. Cr and an excellent plating material having a beautiful appearance can be manufactured. CONSTITUTION:In the vapor-depositing method in which subliming metal contg. Cr as a vapor deposition raw material is evaporated under heating in vacuum or in an atmosphere of a rarefied gas to form a plating layer on the surface of the material to be treated, a solid raw material having <=0.5% porosity is used. In the case the subliming metal is vapor-deposited by using an alloy bath contg. the subliming metal contg. Cr, the vapor deposition is executed as a solid constituted of the subliming metal contg. Cr having <=0.5% porosity is supplied to the alloy bath.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a plated material by vapor deposition of a sublimable metal containing Cr, and more specifically, it contains Cr having an excellent appearance by suppressing the generation of splash during vapor deposition. The present invention relates to a method of forming a sublimable metal plating using a sublimable metal or an alloy bath containing these.

[0002]

2. Description of the Related Art Cr plating is widely used industrially in order to improve wear resistance, corrosion resistance and decorativeness.
This Cr plating can be formed by an electroplating method. For example, Zn-Cr-based or Zn-Cr-Ni-based alloy plating is formed by an electroplating method. However, alloy-plated materials such as Al-Cr alloys and Al-Cr-Ti are difficult to manufacture by the usual electroplating method, and are also difficult to perform by the hot dipping method. Therefore, the plating of these alloys is performed exclusively by the vacuum deposition method.

Generally, in the vacuum vapor deposition plating method, a vapor deposition material is heated and melted by an appropriate means such as high frequency or electron beam and then evaporated, and a vapor deposition film is formed by depositing the generated metal vapor on a substrate. .. However, Cr, Mn, C
Sublimable metals such as o and Mg exhibit a high vapor pressure even under a temperature below the melting point under vacuum conditions, so that sublimation from a solid state occurs without passing through a molten state. When sublimation occurs, sublimation starts from the entire surface of the metal lump, which is the vapor deposition material, and the metal lump becomes smaller and the surface area decreases as the sublimation progresses. It was difficult.

Another problem is that during vacuum deposition, a small lumpy raw material is locally and irregularly scattered and adheres to the adherend, which is called a splash, which significantly impairs the appearance of the plated material. Problems have also been pointed out.

Regarding the problem in vacuum deposition of these sublimable metals, the same applicant as the present invention has disclosed a method of controlling the evaporation amount, and the former problem has already been solved (Japanese Patent Laid-Open No. 3-170661). ). However, the latter splash remained unsolved.

[0006]

In view of the above circumstances, the present invention provides a method for producing an excellent plated material having a beautiful appearance by suppressing the occurrence of splash when vacuum depositing a sublimable metal containing Cr. The purpose is to provide.

[0007]

The structure of the present invention for solving the above-mentioned object is to provide Cr in a vacuum or a dilute gas atmosphere.
Using a solid raw material having a porosity of 0.5% or less in a vapor deposition method of forming a plating layer on a surface of a material to be processed by heating and evaporating a sublimable metal containing Cr as a deposition raw material, and a sublimable metal containing Cr When a sublimable metal is vapor-deposited using an alloy bath containing, the gist is to vapor-deposit while supplying a solid of a sublimable metal containing Cr with a porosity of 0.5% or less to the alloy bath.

[0008]

First, the present inventors investigated the generation state of splash. According to this, it is generated from the solid vapor deposition source at random, and when the vapor deposition source is an alloy bath, when the sublimable metal such as Cr is supplied to the alloy bath, the supply metal and the alloy bath are separated. It was clarified that it occurs violently near the interface. From this, it is considered that the main cause of splash generation is the presence of solid metal. Generally, the Cr raw material used for vapor deposition is obtained by aggregating and sintering powdery Cr, and has a large number of fine pores. The present inventors focused their attention on the existence of these pores, and as a result of investigating the amount of splash generation using sintered materials of various porosities, as the porosity of the vapor deposition raw material decreased, the amount of splash generation was small. The present invention has been made clear by the above. The present invention will be described in detail below.

The sublimable metal used in the present invention is a metal such as Mn such as Cr, Co, or Mg, which exhibits a high vapor pressure even at a temperature below the melting point under a vacuum condition and a high thermal energy. When added, it means a metal that sublimes without showing a molten state.

At present, as a raw material for Cr or the like, a material obtained by crushing an electrolytic product and then sintering it in a lump form using polyvinyl alcohol or the like as a binder is often used. In order to achieve the object of the present invention, it is necessary that these sublimable metal sintered bodies have a porosity of 0.5% or less, and more preferably 0.2% or less in the solid state. This condition is similarly necessary both when the vapor deposition source is used in the solid state and when it is replenished as a solid metal in the alloy bath. Here, the porosity is defined as the area ratio (%) of the pore portion in a constant visual field when the cross-section of the metal solid raw material is observed. The porosity of the sublimable metal solid raw material is 0.5.
When it exceeds%, it becomes difficult to suppress the occurrence of splash. However, if it is 0.5% or less, the generation of splash can be considerably suppressed, and if it is 0.2% or less, the generation of splash can be almost completely prevented.

Although the detailed mechanism by which the pores cause the generation of splash has not been clarified yet, the vapor pressure inside the void-like pores increases during vacuum deposition, causing a local vapor pressure difference, which causes solid powder in the vicinity of the surface. It is presumed that the metal and molten metal components in the alloy bath are blown up and this appears as a splash. The means for reducing the porosity of the sublimable metal raw material is not limited, but as a general industrial method, (1) increase the temperature at the time of sintering the powder metal and increase the sintering time. (2) A method of further performing HIP treatment, CIP treatment, or the like on the sintered metal material may be used.

The metal capable of forming an alloy bath with a sublimable metal containing Cr is not particularly limited as long as it is a metal capable of forming an alloy bath state at a temperature lower than the melting point of the sublimable metal. , Zr, Nb, Mo, Ta, W, A
1 and the like can be preferably used. Periodic or continuous supply of sublimable metal raw material is required to perform continuous vapor deposition.
The present invention is not affected by the supply method. Further, the vacuum deposition method of the present invention includes other PVD methods such as ion plating and dynamic mixing.

[0013]

EXAMPLES The present invention will be described in more detail with reference to the following examples. A vapor-deposited Cr-plated steel sheet was manufactured using the continuous vapor-deposition plating equipment as shown in FIG. Where C
r raw materials having various porosities as shown in Table 1 are used,
The appearance of vapor-deposited plated steel sheets was examined with respect to the vapor-deposited solid steel alone and the vapor deposition source using an alloy bath with Zr, and the results are also shown in Table 1.

[Production conditions] Material to be vapor-deposited: SPCE material (width 150 mm × 0.7 mm thickness) Vapor deposition source: (1) Solid alone Cr simple substance (2) Alloy bath Zr-Cr bath Cr deposition amount: 5-10 g / m ² Deposition degree of vapor deposition chamber: 1 × 10 ^-2 Pa or less Heating source: Pierce type electron gun Evaporation tank: (1) Solid single alumina crucible (2) Alloy bath water-cooled copper crucible Evaporation raw material: Cr raw material Purity 99.6% or more (a ) Porosity adjusting material by vacuum heating at 1000 ° C or more (b) HIP material Raw material replenishment: In the case of Zr-Cr bath, Cr raw material was fed into the bath at a constant rate (the evaporation amount of Zr is very small. No replenishment in the example). No replenishment for Cr alone.

[Evaluation method] A Cr vapor-deposited steel plate was sampled for 5 m,
The splashes adhering to each other were counted by visual observation, and the following three-stage evaluation was performed. ◯: 0 to 1 / m ² Δ: 2 to 5 / m ² ×: 6 or more / m ²

[0016]

[Table 1]

As is clear from Table 1, the porosity is 1.0%.
In the case of the comparative example exceeding 1, a large number of splashes 1 were observed, but it can be seen that almost no splash is observed when Cr having a porosity of 0.2% or less is used. Further, in the case of Cr having a porosity of 0.3 to 0.5%, the effect of suppressing the generation of splash was recognized.

[0018]

As is clear from the above examples, the occurrence of splash is suppressed by using a sublimable metal having a porosity of 0.5% or less as a vapor deposition material or supplying it to the alloy bath. It was possible to obtain a vapor-deposited steel sheet having an excellent appearance.

[Brief description of drawings]

FIG. 1 is a schematic view of a continuous vapor deposition plating facility.

[Explanation of symbols]

 1 vacuum deposition chamber 2 material to be plated 3 support roll 4 electron beam gun 5 electron beam 6 exhaust port 7 crucible 8 raw material

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Atsushi Kihara 1-3-18 Wakihamacho, Chuo-ku, Kobe City Kobe Steel, Ltd. Kobe Head Office (72) Inventor Kuniyasu Araga 1-3, Wakihamacho, Chuo-ku, Kobe No. 18 Kobe Steel, Ltd. Kobe Head Office

Claims (2)

[Claims] 1. A vapor deposition method for forming a plating layer on the surface of a material to be treated by heating and evaporating a sublimable metal containing Cr in a vacuum or a dilute gas atmosphere to form a plating layer, and the porosity is 0.5% or less. A vapor deposition method for a sublimable metal containing Cr, characterized by using a solid raw material. 2. The method of depositing a sublimable metal using an alloy bath containing a sublimable metal containing Cr, has a porosity of 0.
A vapor deposition method of a sublimable metal alloy containing Cr, which comprises depositing a solid made of a sublimable metal containing 5% or less of Cr into the alloy bath.