KR100433729B1 - Sintered compacts manufacturing method of stainless steel for dental implants - Google Patents

Abstract

The present invention can provide a highly desirable metal material as a material for dental implants used in the oral cavity by reducing the pores of the sintered body and increasing the mechanical strength by manufacturing electroless plating of copper on the stainless steel sintered body used as a dental implant. As such, by improving biocompatibility and corrosion resistance, it is possible to provide a dental implant material having superior biocompatibility, a much longer life expectancy, and a lighter weight than a conventional dental implant.

Description

Sintered compacts manufacturing method of stainless steel for dental implants

The present invention relates to a method for producing a stainless sintered body for use as an implant material for dental use, and more particularly to a method for manufacturing a stainless steel sintered body for dental implants excellent in corrosion resistance and biocompatibility.

Dental implants refer to artificial tooth roots made of special metals. Therefore, the most important factor that determines the success of implants should be good bone adhesion, ie biocompatibility between the implant and surrounding bone tissue.

To this end, conventionally, a method of increasing surface roughness by applying hydroxyapatite or titanium particles to the surface of the implant has been used. However, the method described above is not easy to use because the separation between the applied particles and the implant is easy, and even the durability is not good. Ion release occurs in the surrounding bone tissue has a disadvantage that can not obtain sufficient bone adhesion.

Therefore, in recent years, a stainless steel sintered body which is resistant to mechanical impact and has good moldability and corrosion resistance in a corrosion resistant atmosphere has been widely used as a dental implant material.

In addition, since the simple stainless steel powder is inferior in bonding strength, copper (Cu) is added to reinforce it.

However, the conventional stainless steel sintered body uses a method of mechanically mixing and sintering and sintering stainless steel powder and copper powder as shown in FIG. 1, wherein the copper powder 10 gradually melts during sintering. It penetrates between the stainless steel powders 20 and serves to bind these stainless steel powders, and the copper powder 10 remains where the pores 30 remain and the pores are corrosion resistant. Phosphorus has a lung that causes rapid corrosion in the oral cavity.

The present invention is to produce a stainless steel sintered body having better corrosion resistance by minimizing the pores generated by adding Cu as a powder, electroless plating Cu to stainless steel powder and then using the same to produce a stainless steel sintered body very corrosion resistance It is possible to provide excellent implant materials.

1-Reference diagram of a conventional method for mixing stainless steel powder and copper powder and showing that the stainless steel powder is bound by melting the copper powder.

Figure 2-Reference diagram of the present invention to show that the stainless steel powder is bonded to the surface of the stainless steel powder by the electroless plating method and the molten copper during sintering.

Figure 3-Tissue photograph of the stainless steel sintered body for dental implants.

* Explanation of symbols for main parts of the drawings

10: copper powder 20: stainless steel powder

30: pore 40: plated copper

50: molten copper

In order to achieve the above object, the present invention can be used as a dental implant material by electroless plating 2 to 10wt% Cu on stainless steel powder, and rolling and sintering the electroless plated stainless steel powder by a known method. Stainless steel sintered body could be produced.

The reason for limiting the Cu content to 2 to 10% by weight is that when Cu is 2% by weight or less, the bonding strength of the stainless steel powder becomes weak, and when the content is 10% by weight or more, the strength of the sintered body is greatly reduced due to the liquid phase sintering of copper. Because.

Hereinafter, the present invention will be described in detail by way of examples.

In this experiment, the stainless steel powder used as the base metal was an austenitic stainless steel powder, and in particular, an irregular powder (manufactured by Glidden-Metal, manufactured by SCM, USA) was used.

In addition, Cu was used as an additive element used for the binding of the base metal.

As a method for plating Cu on the stainless steel powder, there are an electroplating method and an electroless plating method, but the electroless plating method can determine a metal source when preparing a plating solution, and easily adjust the content of Cu to be plated on the alloy material. In this invention, the electroless plating method was used.

Pretreatment of the stainless steel powder was washed with acetone or ethanol.

Next, after the stainless steel powder was immersed in the electroless plating solution, plating was performed so that the Cu content was 2, 4, 7 and 10 wt%. At this time

^{Cu 2+ + HCHO + 3OH - →} HCOO + 2H 2 O + Cu

^{HCHO + OH - → HCOO + H} 2

As the reaction occurs, metal copper starts to precipitate and hydrogen gas is generated at the same time. Therefore, the overall reaction

^{Cu 2+ + 2HCHO + 4OH - →} Cu + H 2 + 2HCOO - + 2H 2 O

To electroless Cu plating. Apart from the above reaction,

_{^{2HCHO + OH - → CH 3 OH}} + HCOO -

The reaction causes formalin and hydroxide ions to be consumed to produce methanol and formic acid, which can lead to non-catalytic reactions. Also

^{_{2Cu 2 + + HCHO + 5OH -}} → Cu 2 O + HCOO - + 3H 2 O

Cu ₂ O formed in the

^{_{Cu 2 O + 2HCHO + 2OH -}} → 2Cu + H 2 + 2HCOO - + H 2 O

Electroless Cu plating was performed as follows.

The Cu-plated stainless steel powder was reduced in a hydrogen gas atmosphere at 500 ° C. for 30 minutes to remove all oxides formed during the plating process.

Next, electroless Cu-plated stainless steel powder was molded into disk-type specimens at a pressure of 800 MPa using a molding die having a diameter of 12.5 mm and a height of 40 mm to obtain a molding density of 6.8 g / cm2. After heating to 1150 ℃ at a rate of 40 ℃ / min. And sintered for 30 minutes, water cooled, and the structure after sintering was observed through an optical microscope.

Figure 3 is a photograph of the microstructure of the stainless steel (316L) sintered body, (a), (b), (c) and (d) is a conventional method of mixing and sintering Cu powder to stainless steel powder Structure photograph of the sintered compact in the case of manufacture, (e), (f), (g), and (h) are sintered compact structure in the case of manufacturing by this invention sintered by electroless Cu plating to stainless steel (316L) powder It is a photograph.

Particularly, (a) is a structure photograph when a sintered compact is prepared by mixing Cu powder with 2wt% stainless steel powder, and (b), (c) and (d) are 4, 7 and 10wt% stainless steel, respectively. It is a structure | tissue photograph in the case of mixing and sintering in powder.

(e), (f), (g) and (h) are the structure photographs of the stainless steel sintered bodies electroless plated with 2, 4, 7 and 10 wt% of Cu, respectively.

As shown in FIG. 1 in which Cu is added as a powder, when Cu is mixed with a stainless steel powder in a powder state as shown in FIG. 1, relatively large pores are formed in a place where Cu powder is present during the sintering process. In addition, although it is not possible to achieve uniform alloying, as shown in FIG. 2 in which electroless plating of Cu, relatively small pores are formed and alloying is also very uniform.

As described in the above embodiments, the present invention is a stainless steel sintered body prepared by electroplating 2-10 wt% of Cu in a stainless steel powder, compacting and sintering it, and the distribution and size of pores are relatively higher than that of Cu added as a powder. Due to the small size and uniform distribution of Cu, the corrosion resistance is improved, and it is concluded that it is very suitable as a material for dental implants mainly used in a corrosion resistant atmosphere.

As described above, the present invention can improve the biocompatibility by allowing the fine pores on the surface to replace the surface roughness when the implant is manufactured by using the existing stainless steel, and by electroless plating copper, stainless steel sintered body By reducing the pores in the sintered body to improve the corrosion resistance by having a durable, far longer life expectancy, and a lighter weight than the conventional dental implant has the effect of providing a dental implant material.

Claims (1)

In the method of manufacturing a stainless steel sintered body used as a dental implant material in the dental stainless steel powder which is the base metal constituting the stainless steel sintered body, characterized in that the electroless plating of 2 to 10wt% copper, pressed and sintered to manufacture Method for manufacturing stainless steel sintered body for implant.