DE202017101887U1 - An article with a type III anodized surface - Google Patents

Abstract

An article having a type III anodisable surface, preferably consisting entirely of a type III anodizable metal or a type III anodizable metal alloy, characterized by a first layer applied to the Type III anodizable surface by a first coating process, in which a pattern of a type III anodized oxide layer is introduced.

Description

 TECHNICAL FIELD OF THE INVENTION

The invention relates generally to the field of electrochemical surface processing, more particularly to the anodization of metallic surfaces, particularly of titanium, niobium, tantalum, stainless steel and the like. or an alloy of one or more of these substances. More particularly, the invention relates to an article having a type III anodized surface, particularly a surface of titanium, niobium, tantalum, stainless steel and the like. or an alloy of one or more of these substances and with a colored pattern.

 BACKGROUND OF THE INVENTION

In the field of the invention, it has long been known to electrochemically treat metallic surfaces and thereby to build up an oxide layer or to modify an existing oxide layer such that the corresponding surface has different properties after the treatment and e.g. is more resistant to environmental influences and / or colored acts.

Untreated metallic surfaces typically oxidize in the air. Thus, untreated surfaces of titanium or titanium alloys oxidize very rapidly and form a very thin, typically only 0.5 to 1 micron thick colorless oxide layer, which protects the metal from further attack of atmospheric oxygen. However, such an oxide layer is typically quite soft and offers no protection against mechanical stress due to its very low strength.

It was discovered many years ago that the thin natural oxide film of certain metals in an electrolytic bath can be replaced by an oxide film with improved color and protective properties.

In anodizing titanium and titanium alloys, various types of anodization methods are known, known as Type I, Type II, Type III and Type IV. Particularly common in practice are type II anodizing and type III anodizing. While in Type II anodizing the biological and biomechanical properties of the surface of titanium or a titanium alloy undergo a fundamental modification, only the color effect changes in Type III anodizing.

A Type II anodization results in an oxide layer, hereafter referred to as Type II oxide layer, having a thickness typically in the range of 1 to 2 μm, which significantly hardens the thus-treated titanium or titanium alloy surface, and which makes the material more resistant to fatigue. In traumatological implants such as bone screws, bone nails and the like, which are to be removed after a certain time back from the human or animal body, the type II anodizing promotes the removability of the implant from the respective tissue. For other items, e.g. Tools, the Type II anodizing leads to increased durability. Type II anodizing uses a basic electrolyte.

On the other hand, in the type III anodization, an acidic electrolyte is used and an oxide film, hereinafter referred to as a type III oxide film, having a thickness of typically 20 to 200 nm, which acts as an optical interference filter, wherein the thickness of the oxide film is the color impression determined the thus treated surface. If natural light with a continuous spectrum falls on such a surface, all rainbow colors can be generated by adjusting the layer thickness. Type III anodizations are typically used for color marking in workpieces such as screws and medical instruments for ease of distinguishing the corresponding articles. In the jewelry industry and also in glasses and the like, Type III anodizing is used to create aesthetic effects.

The DE 10 2008 008 517 B4 describes the use of Type II and Type III anodization to produce silver-containing surfaces on titanium workpieces.

 DISCLOSURE OF THE INVENTION

In a wide variety of technical fields, there is a desire to have metallic objects, which are generally made entirely of titanium or a titanium alloy, niobium or a niobium alloy, tantalum or a tantalum alloy, stainless steel or a stainless steel alloy, but at least one surface of one of these substances, The term pattern is to be understood here in the broadest sense and includes all types of markings and ornaments, characters, shapes, colors, codes, etc. The pattern can be purely aesthetic in nature and serve only as an ornament eg on an ornament. However, it can also serve for identification and, in particular, be machine-readable, such as, for example, a bar or data matrix code. For example, it is desired to apply a manufacturer's code to medical instruments and to easily distinguish precision screws from one another by means of a colored marking when the screws can not be compared directly.

For the introduction of patterns in medical instruments, implants, jewelry and many other objects for the purpose of marking selbiger have been made various proposals, but bring with it different disadvantages. In the case of type III anodising, for example, the treated surface is completely dyed without certain patterns such as lettering or the like. could be generated. It is also known and common practice to laser mark articles which have been Type II anodized. The laser marking causes a blackening of the appearing after a type II anodization gray surface. Colored patterns can not be created with it.

In addition to anodizing, other surface treatment methods are known for applying a protective layer, usually called a hard-material layer, to metallic surfaces, e.g. physical or chemical vapor deposition or plastic coating. Even objects coated in this way can be laser-marked, but the laser inscription in turn causes only a blackening of the corresponding surface.

Based on this, the object of the invention is to provide an article with a type III anodisable surface, on which an arbitrarily shaped colored pattern, e.g. a company logo, a lettering, a character, a number, a data matrix codes, etc. is generated.

The object is achieved by an object having the features of claim 1. The subclaims relate to advantageous embodiments and developments.

By combining a first coating process, e.g. Type II anodization, with a second coating process, namely Type III anodizing, which have heretofore always been used only as an alternative to each other, i. a surface has hitherto either been e.g. Type II anodized or Type III anodized, in combination with a controlled removal of parts of the layer produced by the first coating process is the first possibility given the possibility marks of any shape and any color effect on Type III anodisierbaren surfaces by type III anodization to create. The invention is based on the surprising finding that the two coating methods can be applied to one and the same workpiece, while hitherto in the professional world always only one or the other method has been applied. As will be described below, it is even possible that both coating processes are Type III anodizing.

Further details and advantages of the invention will become apparent from the following detailed description of preferred embodiments.

 DESCRIPTION OF PREFERRED EMBODIMENTS

A method of forming a colored or protective layer on a Type III anodisable surface, such as Type II and Type III anodization, physical and chemical vapor deposition (most commonly short PVD or CVD coating referred to as "physical vapor deposition" or "chemical vapor deposition") including plasma-assisted CVD coating (often PACVD coating, sometimes also PECVD coating called by "plasma assisted chemical vapor deposition" or "plasma enhanced chemical vapor deposition") ) and the plastic coating, as such are well known to those skilled in the art, so that a detailed description can be omitted here.

In its simplest form, a Type III anodizable surface, e.g. a surface of titanium or a titanium alloy which is to later wear the pattern, first coated with a protective layer, e.g. Type II anodized. But there are also applications conceivable in which due to the fact that the surface is not subject to any special mechanical stress, directly a colored type III anodization is applied to the surface.

Typically, a surface to be coated according to the invention is the surface of a completely made of a metal or a metal alloy article such as a medical instrument, an implant, a screw, a nail, a tool, a piece of jewelry, a pair of glasses, a frame structure or a Component for one of the aforementioned objects. Examples of such frame structures are e.g. Golf cart.

Typically, for Type II anodization, not only a surface or a surface portion, but the entire article is immersed in a corresponding electrolyte bath and the entire article is coated with a type II oxide layer. It is thus hardened and resistant to a variety of mechanical and chemical stresses.

When the step of creating a first, usually protective, layer is completed, a partial removal of the first layer takes place to form the desired pattern, wherein, unlike, for example, in laser marking, the first layer is completely removed at the desired locations, so that the underlying metallic surface is uncovered. It should be noted at this point that the generation of the first layer, that is, for example, the type II anodization, does not have to occur immediately prior to the introduction of the pattern. Rather, objects can also be processed that were treated long ago accordingly. In this respect, the step of forming the first layer is not necessarily immediately preceding the introduction of the pattern. It is also clear to the person skilled in the art that the term pattern here can be understood to mean all kinds of geometric shapes such as circles, triangles, quadrilaterals, rings, but also characters, company logos, bar and data matrix codes, etc., and as will be explained below, It is also possible to introduce a plurality of patterns in succession, which can be supplemented, for example, by a color-effect overall pattern, for example a company logo.

When the first layer has been removed at the desired locations and the metallic surface has been exposed, a Type III anodization is carried out in a manner known per se, whereby a colored Type III oxide layer with a thickness of typically 20 to 200 is applied to the exposed surface nm is generated, which acts on irradiation with visible light as an interference filter and thus produces the corresponding color effect.

The removal of the first layer and the exposure of the underlying metallic surface is preferably carried out by means of lasers, drilling or milling.

Surprisingly, it has been found that the steps of introducing a pattern into the first or the second layer by partially ablating the corresponding layer and exposing the underlying Type III anodisierbaren surface and the formation of a color-effective type III oxide layer on the exposed Surface can be repeated several times by means of Type III anodizing, so as to produce differently colored patterns. Since the filtering effect of the type III oxide layer depends on its thickness, and the thickness of the type III oxide layer depends on the applied voltage, two or more differently colored patterns, e.g. to a logo or to a particular color designation as e.g. from the characterization of resistors by means of colored rings is complementary, so proceed, which, starting from the pattern whose color requires the highest voltage of the respective desired colors, one after the other by exposing the corresponding surface sections and subsequent type III anodizing pattern generated whose color each requires a lower voltage than the color of the previously produced pattern. As has been shown, re-type III lower-stress anodization leaves previously-grown oxide layers unchanged.

The invention advantageously makes it possible to produce any monochrome or multicolor pattern, e.g. geometric shapes, company logos, characters, numbers, bar and data matrix codes. The articles characterized in this way are typically articles which consist entirely of a metal such as titanium or a corresponding alloy, but at least have at least one surface of a type III anodizable metal / metal alloy, in particular medical instruments, implants , Tools, screws, jewelery, frame structures such as Golf cart, spectacles or components of the aforementioned objects.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102008008517 B4 [0008]

Claims (6)

 An article having a type III anodisable surface, preferably consisting entirely of a type III anodizable metal or a type III anodizable metal alloy, characterized by a first layer applied to the Type III anodizable surface by a first coating process, in which a pattern of a type III anodized oxide layer is introduced. An article according to claim 1, characterized in that the first layer is a layer applied by Type II anodizing, Type III anodizing, PVD coating, CVD coating, PACVD coating and plastic coating. An article according to claim 1 or 2, characterized in that a plurality of patterns with different thickness type III oxide layers are applied to the surface. An article according to claim 3, characterized in that the different patterns with type III oxide layers complement each other to a company logo, a lettering, a number or a code. Article according to one of claims 1 to 4, characterized in that the type III anodisierbare surface, preferably the entire article consists of titanium or a titanium alloy, niobium or a niobium alloy, tantalum or a tantalum alloy, stainless steel or a stainless steel alloy. Article according to one of claims 1 to 5, characterized in that the object is a medical instrument, an implant, a tool, a screw, a piece of jewelry, a frame structure, a pair of glasses or a component of the aforementioned objects.