201213624 六、發明說明： 【發明所屬之技術領域】 本發明是有關於一種鉻鍍液，特別是指一種用於製備 功能性鉻鍍層之三價鉻鍍液；本發明另有關於使用該三價 鉻鑛液之電鑛方法。 【先前技術】 由於鉻金屬硬度高、耐磨耗、反射能力佳、耐高溫且 耐大氣腐蝕，若以電鍍方式鍍於物件表面，可增加物件美 觀及耐H因祕電鑛是現代重要的㈣卫程技術 之一。絡鑛層主要分成兩種，分別為裝飾性鉻鐘層（飾絡）以 及功能性鉻鑛層（硬絡）。裝飾性鉻鑛層—般沈積在鎳底材上 ，厚度介於0.003〜2.5微米（㈣；功能性鉻鑛層—般沈積在 鋼底材上，厚度介於2.5〜760微米。 、傳統上為使用六價鉻電鑛液，㈣合金或石墨為陽極 ，被鑛物件為陰極，而電解液主要為絡酸溶液，加上少量 催化劑（硫酸或氟化物）；進行電料，於陰極㈣物件上將 =離：還原成鉻金屬，以形成-鉻表面鑛層。然而鉻 疋種同腐姓性物質，具刺激性及腐飯性，在製程中易 產=鉻酸霧滴，不僅造成電鍍液的損失，亦造成設備腐触 曰力廢軋處理等成本’且急性鉻酸霧滴暴露更會對勞工 &睛及上呼吸道粘獏產生刺激’可能會引起咳嗽 路Γ、頭痛、呼吸困難、喉部潰瘍、肺炎、深吸疼痛與 :空而經長期暴露則可能造成鼻腔黏膜發炎、潰瘍、鼻 α 支氣g炎、氣喘等；其中六價鉻經流行病學家 201213624 及動物的試驗，則已被證實可能含引起人體肺癌。歐盟於 2002年完成「廢電子電機設備指令（WEEE)」及「電子電機 設備中危害物質禁用指令（RoHS)」規範，其中將六價鉻離 子列為禁用的毒性物質，並明訂在2006年7月1曰前須有 替代方案》201213624 VI. Description of the Invention: [Technical Field] The present invention relates to a chromium plating solution, and more particularly to a trivalent chromium plating solution for preparing a functional chromium plating layer; the present invention further relates to the use of the trivalent liquid Electro-mineral method of chromium ore. [Prior Art] Due to the high hardness, wear resistance, good reflection ability, high temperature resistance and atmospheric corrosion resistance of chrome metal, if it is plated on the surface of the object by electroplating, it can increase the appearance of the object and the resistance to H is the modern importance (4) One of the technology. The ore deposits are mainly divided into two types, a decorative chrome clock layer (decoration) and a functional chrome ore layer (hard network). The decorative chrome ore layer is deposited on the nickel substrate in a thickness of 0.003~2.5 microns ((4); the functional chrome ore layer is deposited on the steel substrate with a thickness of 2.5~760 microns. Traditionally Use hexavalent chromium electro-mineral liquid, (4) alloy or graphite as anode, mineral part as cathode, and electrolyte is mainly complex acid solution, plus a small amount of catalyst (sulfuric acid or fluoride); electric material is applied to cathode (four) object Will = away: reduced to chrome metal to form - chromium surface mineral layer. However, chrome tanning species with the same humic substance, irritating and sauteed, easy to produce in the process = chromic acid droplets, not only cause plating solution The loss also causes the cost of equipment corrosion and waste rolling treatment, and the exposure of acute chromic acid droplets will cause irritation to workers & eyes and upper respiratory tract. It may cause coughing, headache, difficulty breathing, Laryngeal ulcers, pneumonia, deep pain and: long-term exposure may cause nasal mucosal inflammation, ulcers, nasal aglycitis, asthma, etc.; hexavalent chromium by epidemiologist 201213624 and animal tests, It has been confirmed that it may contain Human lung cancer. In 2002, the European Union completed the Waste Electrical and Electronic Equipment Directive (WEEE) and the "RoHS" in the Electronic and Electrical Equipment, which listed hexavalent chromium ions as banned toxic substances. There must be an alternative before July 1, 2006.
因此’歐盟針對此議題的跨國性計劃EC〇CHROM (Eco efficient and high performance hard chrome process, 2001)即以三價鉻電鍍技術取代六價鉻電鍍技術，參加的機 構包括所有先進國家的公司或研究機構，如參與該計畫的 曰本Musashi團隊所開發之鍍液的配方成分為：丨13M三氯 化絡、0.67M胺基乙酸（giyCine)、2.43M氣化錢、〇_42M硼 酸以及0.27M三氣化鋁。不過，大部分用來製備功能性鉻 鍵層的二價鉻鍵液於工件表面上之覆蓋力往往不佳，而增 加了實務操作上的難度（尤其是對於形狀稍微複雜的工件）， 此情形在低pH值範圍下操作之鍍液更是明顯。 由上述可知，研發一適用於製作功能性鉻鍍層，操作 上具有安全性且覆蓋力佳之三價鉻鍍液及其之電鍍方法， 是目刖產業界順應國際環保意識與潮流所需努力的目標之 «·— 〇 【發明内容】 因此，本發明之目的，即在提供一種三價鉻鍍液，包 含· 〇.3〜〇_8M之三價鉻鹽、〇·4~1.0Μ之可於水中解離出草 酸根離子的化合物、〇8Μ之鋁鹽、〇 3〜〇 8Μ之硼酸， 以及2-3.5Μ之含有氣化銨的導電物質。 201213624 該三價絡锻液所包含之草酸根離子為扮演一錯合劑的 角色其倉取代[Cr(H20)6]3錯合物結構中的水分子並形成 較具還原活性之三價賴合物，進而促進金屬鉻形成之速 率；銘鹽及刪酸乃作為PH值緩衝劑的角色，但銘鹽相較於 硼酸在pH值較低的操作條件下即可作用，因此本發明建議 可視鑛液之pH值條件來調整該兩者於之該三價鉻鑛液中的 使用濃度；而含有氣化銨的導電物f則為用以提升該三價 鉻鑛液之導電性，可避免因導電性不佳的問題致使操作電 壓過高與鍍液發熱等現象。 本發明之另-目的，即在提供一種使用本發明第一目 的之三價鉻鍍液的電鍍方法： (a) 令本發明之二價鉻渡》與一欲進行電錄處理之工件接觸 :以及 (b) 於一"於20〜50°C之溫度且介於〇 2〜〇 8之pH值的操 作條件下對該二仏鉻錢液施加一介於20~60A/dm2之 電流密度，以進行電鍍。 本發明二價鉻鍍液及利用其之電鍍方法之功效在於： 能提供較傳統電鍍液優異之覆蓋力，可提高電鍍時之電流 利用率與易操作性，並進—步得到具有優良厚度與質量的 功能性鉻鍍層。 【實施方式】 有關本發明之前述及其他技術内容、特點與功效，在 以下將進一步於實施方式與其等之實施例的詳細說明中， 將可清楚的呈現。 201213624 本發明發現，當三價鉻鍍液所含之三價鉻鹽濃声低於 0.3M時，會使得電鍍速率過低；而若高於〇 8M， : _於 ⑴會使得 三價鉻鍍液濃度過高，在操作或靜置時易有溶質析出 建議本發明三價鉻鹽之濃度是介於〇.3〜〇 8M。 較佳地，該三價鉻鹽是擇自於三氯化鉻、三氟化鉻、 硝酸鉻，或此等之一組合。更佳地，該三價鉻鹽是三氣化 絡。 、 在該可於水中解離出草酸根離子的化合物之濃度考量 方面，當其濃度低於0.4M時，會使得三價鉻離子與^酸根 錯合程度不足’不利於後續之鉻金屬沈積；而高於i 時 ，則會使付鍍液濃度過高，在操作或靜置時易有溶質析出 。故建議本發明三價鉻鍍液所含之可於水中解離出草酸根 離子的化合物之濃度是介於〇 4〜丨〇M。 較佳地，該可於水中解離出草酸根離子的化合物是擇 自於草酸、草酸鈉、草酸銨，或此等之一組合。 在忒鋁鹽之濃度考量方面，當該三價鉻鍍液所含之鋁 鹽濃度— 低於G.1M _，會使得三價鉻鑛液以及陰極表面之 PH值容易在電鑛時升高，而造成氫氧化物大量生成並使得 電鑛料明顯下降；當高於〇傭日夺，則會使得三價鉻鑛液 濃度過同在操作或靜置時易有溶質析出。故建議本發明 三價絡鑛液所含紹鹽之濃度是介於0.1〜0.8M。 在該硼I之濃度考量方面，當三價鉻鍍液所含之硼酸 農又低於0.3M 會使得三價鉻鑛液以及陰極表面之 值合易在電料升高，而造成氫氧化物大量生成並使得電 201213624 鑛速率賤下降；而高於G.8M時，則會使得舰濃度過高 在細作或靜置時易有溶質析出。故建議本發明三價絡鑛 液所含紹鹽之濃度是介於〇 3〜Ο·。Therefore, 'Eco efficient and high performance hard chrome process (2001) replaces hexavalent chromium plating technology with trivalent chromium plating technology, and the participating institutions include companies or research in all advanced countries. Institutions, such as the formulation of the bath developed by the Musashi team participating in the project, are: 丨13M trichloride, 0.67M giyCine, 2.43M gasification, 〇42M boric acid and 0.27 M three gasified aluminum. However, most of the divalent chromium-bonding liquids used to prepare functional chromium bond layers tend to have poor coverage on the surface of the workpiece, which increases the difficulty of practical operation (especially for workpieces with slightly more complicated shapes). The baths operating at low pH ranges are more pronounced. It can be seen from the above that the development of a trivalent chromium plating solution suitable for the production of functional chrome plating, which is safe in operation and excellent in coverage, and its electroplating method are the goals of the industry to meet the international environmental awareness and trend. Therefore, the object of the present invention is to provide a trivalent chromium plating solution comprising trivalent chromium salt of 〇.3~〇_8M, and 〇·4~1.0Μ. A compound which dissociates oxalate ion in water, an aluminum salt of 〇8Μ, a boric acid of 〇3~〇8Μ, and a conductive substance containing vaporized ammonium of 2-3.5 。. 201213624 The oxalate ion contained in the trivalent forging fluid plays a role as a binding agent, and its silo replaces the water molecule in the [Cr(H20)6]3 complex structure and forms a trivalent complex with a reducing activity. The substance, in turn, promotes the rate of metal chromium formation; the salt and the acid are used as the pH buffer, but the salt is effective compared to the boric acid under the operating conditions of lower pH, so the present invention suggests a visible mine The pH condition of the liquid is used to adjust the concentration of the two in the trivalent chromium ore liquid; and the conductive material f containing the vaporized ammonium is used to enhance the conductivity of the trivalent chromium ore liquid, thereby avoiding the cause The problem of poor conductivity causes the operating voltage to be too high and the plating solution to heat up. Another object of the present invention is to provide an electroplating method using the trivalent chromium plating solution of the first object of the present invention: (a) contacting the divalent chromium crucible of the present invention with a workpiece to be subjected to electro-recording: And (b) applying a current density of 20 to 60 A/dm 2 to the diterpene chromium liquid at an operating temperature of 20 to 50 ° C and a pH between 〇2 and 〇8, For electroplating. The divalent chromium plating solution of the invention and the electroplating method using the same have the advantages of: providing superior coverage of the conventional electroplating solution, improving current utilization and ease of operation during electroplating, and further obtaining excellent thickness and quality. Functional chrome plating. The above and other technical contents, features and effects of the present invention will be apparent from the following detailed description of the embodiments and the embodiments. 201213624 The invention finds that when the trivalent chromium salt contained in the trivalent chromium plating solution has a concentration lower than 0.3M, the plating rate is too low; and if it is higher than 〇8M, : _(1) causes the trivalent chromium plating The liquid concentration is too high, and it is easy to have solute precipitation during operation or standing. It is suggested that the concentration of the trivalent chromium salt of the present invention is between 〇.3 and 〇8M. Preferably, the trivalent chromium salt is selected from the group consisting of chromium trichloride, chromium trifluoride, chromium nitrate, or a combination thereof. More preferably, the trivalent chromium salt is a three gas phase. In terms of the concentration of the compound capable of dissociating the oxalate ion in water, when the concentration is less than 0.4 M, the degree of mismatch between the trivalent chromium ion and the acid group is insufficient to be detrimental to the subsequent chromium metal deposition; When it is higher than i, the concentration of the plating solution is too high, and it is easy to precipitate solute during operation or standing. Therefore, it is suggested that the concentration of the compound which can dissociate the oxalate ion in water contained in the trivalent chromium plating solution of the present invention is between 〇 4 and 丨〇M. Preferably, the compound which cleaves the oxalate ion in water is selected from the group consisting of oxalic acid, sodium oxalate, ammonium oxalate, or a combination thereof. In terms of the concentration of bismuth aluminum salt, when the concentration of aluminum salt contained in the trivalent chrome plating solution - lower than G.1M _, the pH value of the trivalent chrome ore and the surface of the cathode is easily raised in the electric ore. As a result, a large amount of hydroxide is formed and the electric ore material is significantly reduced; when it is higher than the servant, the concentration of the trivalent chromium ore is too easy to be precipitated when it is operated or left. Therefore, it is suggested that the concentration of the salt contained in the trivalent complex ore solution of the present invention is between 0.1 and 0.8M. In terms of the concentration of boron I, when the trivalent chromium plating solution contains less than 0.3M of boric acid, the value of the trivalent chromium ore and the surface of the cathode is easily increased in the electric material, resulting in hydroxide. A large number of generations and electricity 201213324 mine rate 贱 decline; and higher than G.8M, it will make the ship concentration too high, easy to have solute precipitation when fine or standing. Therefore, it is suggested that the concentration of the salt contained in the trivalent complex ore solution of the present invention is between 〇 3 and Ο·.
本發月二彳貝鉻鍍液所加入的導電物質可以是單一種類 的氣化知亦可含有氣化録並且再混合不同種類的導電鹽（ 鉻鹽及鋁鹽除外)。因為氣化銨的銨根離子於電鍍操作時， 在陽極會被氧化成氮氣，除了可抑制三價鉻離子氧化成六 7絡離子’以避免六價鉻離子的生成對陰極的鉻沈積程序 每成不n，另―？「面，亦可減輕陽極的氯氣生成反應 而故成操作者的危I為達到前述之目的，故本發明三價 鉻鍍液所加人的導電物質至少會含有氯化錄，且建議該含 有氯化錄的導電物質之濃度是介於2~3.5Μ。 較佳地，該含有氣化錄的導電物質是氣化錢、氯化敍 與氣化卸、氯⑽與氯仙，或象域與氯㈣及氣化納 之一組合。 力遂鐵的疋··當氯化錢與不同種類的導電鹽（絡鹽及紹 鹽除外）混合使用作為㈣物質時，則應隨之調整本發明三 價鉻鑛液之其他組成成分的使用濃度範圍。較佳地該三 價鉻鹽之濃度是介於〇 4〜〇 6Μ、兮π # , ^ _該可於水中解離出草酸根 離子的化合物之濃度是介於Λ 辰又疋"於0.6〜〇.8Μ、該紹鹽之濃度是介 於0.2〜0.6Μ，及硼酸之濃度是介於〇 4〜〇 6μ。 —步說明，但應瞭解的 而不應被解釋為本發明 本發明將就以下實施例來作進 疋，該等貫施例僅為例示說明之用， 實施之限制。 201213624 〈實施例1~9及比較例> 依表1所列之配方組成及濃度，在常溫常壓下將各組 份予以混合而製得本發明實施例U之三價絡鍵液，另外 :表i中也列出參與ECOCHROM計畫中的日本團 隊所開發之鍵液作為比較例。 表1.The conductive material added to the mussel chrome plating solution of the present month may be a single type of gasification, or may contain gasification recording and further mixing different kinds of conductive salts (except chromium salts and aluminum salts). Because the ammonium ion of the vaporized ammonium is oxidized to nitrogen at the anode during the electroplating operation, in addition to inhibiting the oxidation of the trivalent chromium ion into a hexa- 7 complex ion to avoid the formation of hexavalent chromium ions on the cathode chromium deposition procedure Not n, another? "The surface can also reduce the chlorine gas formation reaction of the anode, so that the operator's risk I achieves the above purpose. Therefore, the conductive material added to the trivalent chromium plating solution of the present invention contains at least a chloride product, and it is recommended to contain The concentration of the conductive substance recorded by the chlorination is between 2 and 3.5. Preferably, the conductive substance containing the gasification record is gasification money, chlorination and gasification, chlorine (10) and chlorin, or image domain. Combination with chlorine (4) and gasification nano. When chlorinated money is mixed with different kinds of conductive salts (except complex salts and salt) as (4) substances, the invention should be adjusted accordingly The concentration range of the other constituent components of the trivalent chromium ore liquid. Preferably, the concentration of the trivalent chromium salt is between 〇4~〇6Μ, 兮π#, ^ _ which is a compound which can dissociate the oxalate ion in water. The concentration is between 辰辰又疋" at 0.6~〇.8Μ, the concentration of the salt is between 0.2~0.6Μ, and the concentration of boric acid is between 〇4~〇6μ. It is to be understood that the present invention will not be construed as being For the purpose of illustration and limitation, the implementation is limited. 201213624 <Examples 1 to 9 and Comparative Examples> According to the formulation and concentration listed in Table 1, the components are mixed under normal temperature and pressure to obtain the present invention. The trivalent complexing solution of Example U, in addition: Table i also lists the key solution developed by the Japanese team involved in the ECOCHROM program as a comparative example.
[三價鉻鍍液覆蓋性能測試】 本發明測試係將實施例1〜9之三價鉻鍍液於哈氏槽 (Hull cell)中’陽極採用實驗級石墨板，陰極則採用鐵片， 以操作電流5安培（A)進行3分鐘的測試，溫度設定為3〇〇c ;而比較例亦以相同之條件進行測試，但其溫度設定則是 採用Musashi團隊在公開資料中的最佳溫度5〇。<：進行測試 〇 由於哈氏槽中陰極與陽極板不平行，陰極試片上各部 位與陽極的距離是不相同的：陰極的總長是l〇cm，故本發 201213624 月在。氏槽的測試中，離陽極最近的陰極試片位置標示為 0Cm，而離陽極最遠的陰極試片位置則標示為離陽 極較近的—端電流密度（current density，A/cm2)較大，且隨著 陰極與陽極的距離增大，電流密度會逐漸變小，其中，試 片光亮區間的最大電流密度值’即為「上限電流密度」，而 試片光壳區間的最小電流密度值，即為「下限電流密度」。 因此，在〇cm處的陰極電流密度最大，而在丨㈧爪處的陰極 電流密度最小。則各纽三價鉻鍍液之覆蓋能力的好壞，乃 可藉由哈氏槽試片光亮區間的範圍來判斷，即光亮區間越 大（上限與下限電流密度的差距越大），覆蓋能力就越好陰 極位置與陰極電流密度之關係如圖1所示。 三價鉻鍍液在進行測試後，於記錄哈氏槽測試片的光 亮區間位置範圍時，藉由哈氏槽測試片之位置（cm)及其相對 應之電流密度（A/cm2)之關係圖（如圖1) ’便可以換算得光亮 區間的電流密度範圍。由於實施例丨與比較例數據中的 上限電流密度皆已達極限值位置（0cm)(圖未示），因此，本 測試只需比較各組之陰極試片的下限電流密度位置（cm)，即 可評估鍍液的覆蓋能力與性能。而將下限電流密度位置（cm) 代入下列之關係式中’即可得知三價鉻鍍液於操作時之下 限電流密度值。 下限電流密度=操作電流x[5.1-5.24x(log1C)下限電流密度位置)] 本發明三價鉻鍍液與比較例鍍液所測得之下限電流密 度位置的數值列於下表2中。 201213624 表2.[Trivalent chromium plating solution coverage performance test] The test of the present invention uses the trivalent chromium plating solution of Examples 1 to 9 in a Hull cell, the anode is an experimental grade graphite plate, and the cathode is an iron plate. The operating current is 5 amps (A) for 3 minutes and the temperature is set to 3 〇〇c. The comparative example is also tested under the same conditions, but the temperature setting is based on the optimum temperature of the Musashi team in the public data. Hey. <: Test 〇 Since the cathode and anode plates are not parallel in the Hastelloy groove, the distance between the various parts of the cathode test piece and the anode is different: the total length of the cathode is l〇cm, so the present issue is 201213624. In the test of the groove, the position of the cathode test piece closest to the anode is marked as 0Cm, and the position of the cathode test piece farthest from the anode is marked as closer to the anode - the current density (A/cm2) is larger. And as the distance between the cathode and the anode increases, the current density will gradually decrease. The maximum current density value of the test piece bright interval is the "upper limit current density", and the minimum current density value of the test piece light-shell interval , which is the "lower current density". Therefore, the cathode current density at 〇cm is the largest, and the cathode current density at the 丨(八) claw is the smallest. The coverage of each trivalent chrome plating solution can be judged by the range of the Hahn's groove test piece, that is, the larger the light interval (the greater the difference between the upper limit and the lower limit current density), the coverage capability The better the relationship between the cathode position and the cathode current density is shown in Figure 1. The relationship between the position (cm) of the Hastelloy test piece and its corresponding current density (A/cm2) when the trivalent chrome plating solution was tested after recording the range of the bright interval of the Hastelloy test piece. Figure (Figure 1) 'You can convert the current density range of the bright interval. Since the upper limit current density in the data of the example and the comparative example has reached the limit value position (0 cm) (not shown), the test only needs to compare the lower limit current density position (cm) of the cathode test piece of each group. The coverage and performance of the bath can be evaluated. By substituting the lower limit current density position (cm) into the following relationship, the lower current density value of the trivalent chromium plating solution at the time of operation can be known. Lower limit current density = operating current x [5.1 - 5.24 x (log 1 C) lower limit current density position) The values of the lower limit current density positions measured by the trivalent chromium plating solution of the present invention and the comparative plating solution are shown in Table 2 below. 201213624 Table 2.
<應用例>電鍍處理 以本發明電鑛方法進行一鐵質工件的電鑛處理之步驟 如下： )字貫把例9所得之二價鉻鑛液加入一陽極為實驗級石墨 板而陰極則為一鐵質工件之電鍍槽（哈氏槽）中，以使該 -價鉻鍵液與該欲進行電鍵處理之鐵質工件接觸；及 (2)在pH為0.3、溫度為3〇〇c以及電流密度為4〇α_2的 條件下，於鐵質工件表面進行直流電鍵2小時。 ，本發明電鑛方法可於鐵質工件表面得到一厚度達 微米’且硬度it 800HV之非晶態功能性鉻鑛層，由外觀上 可看出其鑛層光澤相當接近以六價鉻製程製備之工件。進一 10 201213624 步利用知 ife式電子顯微鏡（scann丨ng electr〇n microscope， SEM，Hitachi，S4800, Japan)觀察鍍層上之表面形態，其結果 如附件1(放大倍率為5,〇〇〇倍）所示，可以發現其表面顆粒 相當地小（粒徑大小分佈為2〜3微米），此現象應為使用本發 明二價鉻鍍液所得之鍍層可具有相當的金屬光澤之主要原因 ，而在同等厚度下，一般三價鉻鍍液所製備之鍍層顏色皆近 似銀白色且少有光澤，則因為其顆粒大小皆大於1〇微米所 致（圖未不）。另外，亦以SEM觀察該鍍層之橫截面，由附 件2(放大倍率為500唔）所示的鍍層橫截面圖中，可發現利 用本發明二價鉻鍍液之電鍍方法所製備之鉻鍍層無明顯之大 裂痕（由鍍層表面深入至底材之裂痕），係為具有良好質地的 功能性鉻鍍層。 ’•’τ'上所述，使用本發明三價鉻鑛液及電鑛方法來製備 功能性鉻鍍層時，能提供較一般常見鍍液優異之覆蓋能力 ’不僅可提高電錄之操作性能，且可製備出厚度至少為12〇 微米以上硬度800HV之非晶態絡鑛層，而該鑛層光澤則 相當接近以六價鉻製程製備之工件，對於取代六價鉻離子 鍍液之使用及傳統之電鍍方法皆有明顯之改進，以增進本 領域之產業的進展。 准以上所述者，僅為本發明之較佳實施例而已，當不 月以此限定本發明實施之範圍，即大凡依本發明申請專利 範圍及發明說明内容所作之簡單的等效變化與修飾，皆仍 屬本發明專利涵蓋之範圍内。 201213624 【圖式簡單說明】 圖1是一位置與電流密度之關係圖，說明三價鉻鍍液 於哈氏槽進行覆蓋性能測試之結果。<Application Example> Electroplating Treatment The steps of performing the electromineral treatment of an iron workpiece by the electrominening method of the present invention are as follows:) The divalent chromium ore solution obtained in Example 9 is added to an anode as an experimental grade graphite plate and a cathode. In the plating bath (Harrington cell) of an iron workpiece, the valence chromium bond liquid is brought into contact with the iron workpiece to be subjected to the electric bond treatment; and (2) the pH is 0.3 and the temperature is 3〇〇. c and DC current on the surface of the iron workpiece for 2 hours under the condition that the current density is 4 〇α_2. The electrominening method of the present invention can obtain an amorphous functional chrome ore layer having a thickness of up to micrometers and a hardness of 800 HV on the surface of the iron workpiece, and the appearance of the ore layer gloss is quite close to that prepared by the hexavalent chromium process. The workpiece. Into a 10 201213624 step, the surface morphology on the coating was observed using a scanning electron microscope (scann丨ng electr〇n microscope, SEM, Hitachi, S4800, Japan), and the results are as shown in Annex 1 (magnification 5, 〇〇〇 times). As shown, it can be found that the surface particles are relatively small (particle size distribution is 2 to 3 microns), which should be the main reason why the coating obtained by using the divalent chromium plating solution of the present invention can have a relatively metallic luster. At the same thickness, the color of the coating prepared by the general trivalent chromium plating solution is almost silvery white and less lustrous, because the particle size is greater than 1 〇 micron (not shown). In addition, the cross section of the plating layer was also observed by SEM. In the cross-sectional view of the coating shown by the attachment 2 (magnification: 500 Å), it was found that the chrome plating prepared by the electroplating method of the divalent chromium plating solution of the present invention was Significantly large cracks (from the surface of the coating to the cracks in the substrate) are functional chrome coatings with good texture. As described in '•'τ', when the functional chrome plating layer is prepared by using the trivalent chromium ore liquid and the electric ore method of the present invention, it can provide an excellent covering ability compared with a common common plating liquid, which not only improves the operational performance of the electric recording, And an amorphous ore layer having a thickness of at least 12 〇 micron and a hardness of 800 HV can be prepared, and the gloss of the ore layer is quite close to that of the workpiece prepared by the hexavalent chromium process, and the use and tradition of replacing the hexavalent chromium ion plating solution There have been significant improvements in the plating methods to enhance the progress of the industry in this field. The above is only the preferred embodiment of the present invention, and the scope of the present invention is limited by the scope of the present invention, that is, the simple equivalent change and modification of the patent application scope and the description of the invention. All remain within the scope of the invention patent. 201213624 [Simple description of the diagram] Figure 1 is a plot of the relationship between position and current density, showing the results of the coverage test of the trivalent chromium plating bath in the Hastelloy.
12 201213624 【主要元件符號說明】無12 201213624 [Description of main component symbols] None
1313