NON-ELECTROLYSIS POLISHING METHOD OF TITANIUM PARTS

• Main Author: YOUN, JAE HO
• Format: Patent
• Language: English; Korean
• Published: 03.04.2019
• Subjects: CHEMICAL SURFACE TREATMENT; CHEMISTRY; CLEANING OR DEGREASING OF METALLIC MATERIAL BY CHEMICALMETHODS OTHER THAN ELECTROLYSIS; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATIONOR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING MATERIAL WITH METALLIC MATERIAL; COATING METALLIC MATERIAL; DIFFUSION TREATMENT OF METALLIC MATERIAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION INGENERAL; METALLURGY; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLICMATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASSC23 AND AT LEAST ONEPROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25; NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE

The present invention relates to an electroless polishing method of a titanium part. According to the present invention, titanium used for parts of a vehicle, a semiconductor, and medical appliances can be gloss, and burr on the surface of the titanium can be removed by barrel polishing, buffing, and electrolytic polishing. The electroless polishing method enables polishing of an inner diameter of a pipe bent and polishing of the inner diameter of a small diameter which is a weakness of electrolytic polishing, the buffing, and the barrel polishing and can prevent adsorption of barrel stone powder on the surface of a product and jamming of the barrel stone. The electroless polishing method cannot generally evenly polish the titanium part using the electroless polishing but the existing electrolytic polishing cannot evenly polish the inner diameter which is bent and the small diameter for an electric property to use the electricity. The electroless polishing method comprises: a preprocessing step of removing foreign substances remaining on the surface by melting organic matters strongly attached to the surface from the surface of the titanium part by a chemical reaction by soaking the titanium part into an alkali aqueous solution and a surfactant; an electroless polishing step of reacting the titanium part after the preprocessing step by dipping the titanium part in an electroless polishing liquid for 30 minutes to 5 minutes, wherein the electroless polishing liquid is composed of 100 parts by weight of water at the temperature of 30-60°C, 2-50 parts by weight of hydrofluoric acid, 3-50 parts by weight of nitric acid in the concentration of 67%, and 3-50 parts by weight of a polish; a neutralizing step of treating the titanium part after the electroless polishing step by putting the titanium part into 50g/L of calcium hydroxide; a washing step of washing the titanium part after the neutralizing step with water; and a drying step of drying the titanium part at room temperature after the washing step. 본 발명은 의료기 및 반도체, 자동차 등등의 부품에 사용되는 티타늄은 바렐 연마, 빠우 및 전해연마로 표면 버 제거, 광택을 낼 수 있지만 티타늄 무전해 연마를 하게 되면 바렐 연마, 빠우 연마 와 전해연마의 단점인 소구경의 내경 연마, 밴딩 된 파이프의 내경 연마가 가능하며, 제품 표면의 바렐석 가루의 흡착, 바렐 석의 낌 등을 방지할 수 있으며, 종래의 전해연마는 전기를 사용하기 때문에 전기 특성상 소구경 및 밴딩 된 내경의 일정한 연마가 불가능하지만, 무전해 연마를 이용하면, 전체적으로 고른 연마가 가능하도록 한 티타늄 부품의 무전해 연마방법에 관한 것으로서, 티타늄 부품을 알카리 수용액 및 계면활성제에 담구어 표면에 강하게 부착되어 있는 유기물을 티타늄 부품의 표면에서 화학반응으로 용해하고 녹여내는 처리를 하면서 표면에 잔존하는 이물질들을 제거하는 전 처리단계와; 상기 전 처리단계 후의 티타늄 부품을 온도 30℃~60℃의 물 100중량부에, 불산계의 산 2~50 중량부와, 농도 67%의 질산 3~50 중량부 및 광택제 3~50 중량부를 혼합하여 조성된 무전해 연마액에 30초~5분간 침지하여 반응시키는 무전해 연마단계와; 상기 무전해 연마단계 후의 티타늄 부품을 수산화칼슘 50g/L에 넣어 처리하는 중화단계와; 상기 중화단계 후 티타늄 부품을 물로 씻어 내는 수세단계; 및 상기 수세단계 후, 티타늄 부품을 상온에서 건조하는 건조단계로 이루어진 것을 특징으로 한다.