I247826 玖、發明說明： 【發明所屬之技術領域】 本！X月係有關種解決銘基材與鍍層間附著性不良 製程，以 HN〇3、HF、Η μ 2 〇4浴液铋蝕的方式將鋁合金鑄件表面去合金化與 織射,丨j放人卸與異丙_混合溶液進行⑦的侧，使共晶石夕組 如L私’造成禱件表面孔洞更深；電鑛後銘合金鑄件之底層錄與基 許夕树根狀的接觸面，這些樹根狀的接觸面是因為侧處理時表面 石f份被侧所遺㈣空缺，提供了_錄_軌好附著環境，以提 间電鑛製程巾IS基材表面與錄賴之附著性。 又，本發明在上猶處理餘巾，特職有_提供—種方法解決銘合 金與鍍層間之附著性問題。 【先前技術】 電鑛疋表面處理:L業巾最常使用的—種方式，電鍍應則〖圍極廣，除 在各種金屬上皆可施予電鐘外，現今亦已發展在塑膠上電鑛。由於電鑛 的设備與操作均較痛單’控制容易’且其發展歷史悠久，在技術上有一 定的水準，現已廣泛的應用於表面處理工業。 鋁的標準還原電位是負值（Ε〇=-1·67ν)，我們無法在水溶液中進行析出 的工作，因此紹合金電鍍之所有的步驟都在有機電解溶液或溶鹽浴狀態下 進行。鋁在週期表中屬於高氧化電位的元素，因此鋁會和還原電位較高的 金屬發生化學置換，常用金屬的氧化電位大小的順序為：K>Ca>Na>Mg 1247826 >Al>Zn>Cr>Fe>Sn>Pb>H>Cu>Hg>Ag>Pt>Au 〇 鋁是化學活性很強的金屬，但在乾燥的空氣中可長久維持美觀的光澤， 係由其表面所生成無色透明氧化膜的保護所致。但此氧化膜之厚度只有i 〜10nm，達不到充分防蝕之目的。 鋁合金的種類繁多，因為強度及某些特定需求常會加入其他合金元素， 例如矽、鎂、銅等等，這些成份往往造成鍍件表面的不均一性，造成不良 錢件’因此必須在前處打財將這麵份自表面清除村確保鐘層的密 著性及連續性。 在鋁及其合金電鍍時，比其他金屬材料的電鍍有較多之困難，若以在鐵 或銅上的普通電鍍法施用於鋁材的電鍍上，只能一時暫時性的保蠖表面， 若長時置於_的空氣中，錄層容易會到處膨起與剝離，且電鑛層的機械 性質不良，常發生針孔及其他缺陷。比起其他金屬，為電化學陽性，彼 覆若有上述缺陷，容易造成該處產生腐蝕，使彼覆層剝離。 產生此種缺陷之原因可歸納為： L電化學陽性強 2·表面容易形成氧化膜 3·鋁會被電解液侵蝕 4·金屬内部及鍍層容易形成氣泡 S·鋁中有不純物存在 6·電鍍金屬與鋁無法形成合金 1247826 7·電解液殘留存金屬孔隙中 8·鋁與電鍍金屬的熱膨脹係數不同 電鍍(Electroplating)是指藉著通直流電於電鍍槽中，使金屬離子在被鍍 物表面還原成金屬原子，並成長為鍍層的操作。在電鍍槽中進行還原反應 之端稱為陰極(Cathode)，而進行氧化反應之端則稱為陽極(Anode);進行上 述反應的介質則稱為電鍍液，其係由電解質、水及一些必要成份構成。電 鍵的製程大致可分為研磨（Polishing)、前處理（Pretreatment)、電鑛 (Electroplating)、後處理(after treatments)與乾燥(drying)等五大步驟。 根據法拉第(Faraday)定律，通過電流量和電解所得沈積數量間的關係 96500 其中W表示參與反應物質的質量（以g為單位），1表示通過電流量（安 培）’ t表電解操作的時間（秒），e表每個參與反應物質的電荷量。理論上 1法拉第的電量應生成1克當量的原子，但實際上電鍍之析出受到電鍍條件 與鍍浴之影響，通常電流效率小於100%，故不能完全符合其定律。 一般工業在鍍層上較常用的電鍍有鍍鎳、鍍銅與鍍鉻： (一)·鍍鎳： 錄常用於鋼鐵、黃銅、鋅及銘合金的電鍵，可為裝侧及防腐_。常 用的鎳鑛液是Watts浴’發展於八十年前，其操作與維護甚方便。伽8浴 基本上係由碰鎳及部份氣化物與魏組成，_為緩鋪，而氣化物 1247826 用以促進陽極溶解。典型製程為在操作溫度30-40°C之間，鍍浴配方含有 NiSCV7H2〇 250g/l + NiCl2.6H2〇 40g/l + H3B〇4 25g/卜鍍液之 pH 值約在 5·2-5·8之間’電流密度為2-4 A/dm2。若鑛件所使用的環境腐蝕不顯著時， 鍵層厚度8〜13μιη即夠；但在高腐蝕的環境下，鍍鎳層厚度須成25〜3〇μιη ; 在鍍件上另電鍍0.25〜0·50μιη厚度之鉻，可顯著延長耐用年數。 (；二).鍍銅： 銅常被使用當作中間層，具有平整鍍層的作用，並可防止自然置換與確 保鍍層密著性。常用鍍浴配方為在室溫下，含有CuS〇4.5H2〇 16〇_22〇§/1及 HAO4 50-75g/l的鍍浴，電流密度為2〜4 A/dm2。一般而言，本方法需要較 高的銅含量’而硫酸則用以降低硫酸銅的溶解度，所以銅含量不可太高以 免造成結晶析出。硫酸對硫酸銅溶解度的影響，基本上硫酸濃度越低，則 硫酸銅溶解度越大。 (三).鍍鉻： 為了增進銘及其合金的耐蝕性常對鍍件做鍍鉻處理；同時，鉻的耐磨耗 性大’紹合金用於車軸時，若在接觸轴承的部份鍍鉻，可有與鋼製轴承同 程度的耐磨耗性。常用鍍鉻配方為Cr〇3 4〇〇 g/1 + H2S〇4 4的，操作溫度在 40-50°C之間，而電流密度在3〇_8〇A/dm2之間。 一般而s紹合金由成品素材到電鍍完成須經過研磨、脫脂、酸浸潰、鋅 置換（鋅Μ處理）、電鑛及後處理等程序。纟中脫脂、酸浸潰麟置換為 -般所說的前處理製程，此步驟之電鍍攸合金電鍍的有效性。 1247826 習知铭合金钱經鋅酸鹽處理之電齡序依合金錯而異，一般 為.β洗—瘵ru法去油或溶劑脫脂―鹼性溶液清洗—清洗—浸酸—清 洗—鋅酸鹽處理—清洗—雙重清洗〜電鍍。 刖處理不完全所產生的電鑛缺陷為： 1·鍍層會剝離或產生氣泡 2·電鍍有凹凸和小孔 3·由於氣泡的產生導致電鍍製品耐蝕性降低 4·電鍍層脆化 5·光澤度不均一 而電鑛的不良率有8G%以上是由前處理不佳所引起，因此，紹及其合 金電鍍時，比其他金屬材料的電鍍有較多之困難，主要的原因是發生在鋁 基材與鍍層間附著性不良而導致鍍層容易剝離。 【發明内容】 鋁合金鑄件的電鍍一直是件困難的製程，由於鋁合金鑄件内部含有孔 洞’經過賴後有魏洞會露出，雖然電鍍時會覆蓋過去，但由於孔洞内 含軋體’因此電鑛後會出現水泡(仙贫沉)的現象。 另一方面，鋁合金鑄件本身表面的成份極不均勻，常常使得前處理製程 無法有效的達成。改善方法有二，一為改良鋁合金鑄造過程使鑄件的孔隙 率降低或完全消除，另一解決方法為有效的酸液浸潰。經過有效的酸洗， 可以獲得一個均一性良好而適合電鍍的鑄件表面，如此才能對表面複雜的 1247826 鋁合金鑄件施以電鍍工程。 本發明專利主要係解決鋁基材與鍍層間附著性不良的問題，以提供一種 方法解決此方面之問題。一般常用之鑄造用鋁合金多為鋁_矽亞共晶材料， 亞共晶鋁_矽合金凝固時，一開始先形成初晶相(初晶鋁），當熔液濃度達至 共晶成分時，即形成鋁-矽共晶組織。共晶矽形狀、大小及分佈情形，主要 文到合金成分、凝固速率及調質等因素的影響。在鋁合金中添加微量的鳃 (Sr)、錄(Sb)或納(Na)等元素，會使得原本針狀或板狀的共晶矽尖端鈍化而 轉變成較圓的組織結構，藉以提昇機械性質。 當鋁合金曝露於含氧的大氣中，在瞬間即生成八12〇3氧化膜，此氧化膜 若給予充足的時間及適當的溫度，Al2〇3氧化膜會從非晶體轉變成結晶體。 由於ΑΓ3的擴散速率在結晶體中遠較非晶體為快，因此結晶體的氧化膜會 安定下來而不再氧化。 在物可促進非晶體氧化膜變成結晶體，Mg在紹合金中會促使MgO 生成’特別是在含量超過〇.5%wt的鋁合金中，因MgO表面能低於A1203， 於是優先生成化合物。當MgO進入Al2〇3膜中，即形成MgAi2〇4(鎮鋁尖晶 石 ’ magnesium Aluminum Spinel)，其結晶動力比 a12〇3 為高。 由上述可知，一般常用之鑄造用鋁合金鑄件表面組織為初晶鋁與鋁_矽 共晶組織’且表面外層因氧化而形成八丨2〇3或MgAl2〇4之氧化膜。如圖1 所示即是一般工廠所電鍍的鍍層截面金相，明顯看出鍍層與機材的接合面 較為平滑，並有許多矽的殘留，接合面的平滑會降低附著力，而接合表面 1247826 存在的矽會形成鍍層破壞剝落的開端。而依照電鍍工廠採用的電鍍製程所 電鍍後的銘&金鱗件在2()叱淬火下便已經產生大量氣泡，顯示其電鍍試片 的密著度極差，無法魏加麟火的考驗。 針對鑛層產生氧泡的地方取其截面觀察金相組織，由圖2可看出鏟層破 裂是從紹祕表面含树元素的部·始向时舰，目為這些未被侵钱 7〇王的矽無法與辞離子產生置換，因此造成表面有些含石夕的小凹洞，在電 鍍時攻些不反應的凹洞和鍍層間無法有效緊密的接合，使電鍍時產生的氫 氣殘留在其巾。這些殘㈣氫較_脹，就會從接合面發生膨脹突起， 產生巨觀上所見的氣泡。 本發明專利主要係針對鑄造用鋁合金鑄件在電鑛製程中表面前處理，進 行禱件表面去除Al2〇3或MgAl2〇4之氧化膜，並在表面以 洛液觸方式將齡金鑄件表面去合金化與孔洞化，再放人氫氧化卸與 異丙醇的混合溶液進行;^祕刻，使共晶_組織#刻更深 ，造成鑄件表面 孔/同更深’以提局電鑛製程中!呂基材表面與鍵層間之附著性，如圖3所示 即為本發明專獅表面前處理方法處理後，進行魏製程之鍍層截面金 相，顯不底層鎳與基材間有許多樹根狀的接觸面，這些樹根狀的接觸是因 為钱刻處理時表面;^成份被侵#所遺留的空缺，提供了鍍層與基材間的良 好密著環境。 【實施方式】 铸造用紹合金鑄件電鍵流程如圖4所示，製程參數如圖5所示，電鑛前 11 1247826 處理肌程首先將鋁合金鑄件置入50-60°C脫脂溶液中進行化學脫脂手續，因 銘的化學活性極高，表面在空氣中生成的氧化膜有保護作用。但氧化膜會 /容於NaOH ’ §金屬面直接接觸溶液時，鋁容易被侵餘，在氧化膜侵钱期間 不曰產生氫，但當鋁被侵钱時，則會產生大量氫氣，其反應如下式： 2Al+2Na0H+2H20-^2NaA102+3H2 脫脂後的試片經過兩次水洗後再置入酸洗液中進行酸浸潰，在鋁合金表 面有許多添加的合金元素，這些元素並不會與鋅產生置換作用，若以此直 接做辞酸鹽處理會造成表面的置換層不連續之現象，進而導致電鍍的失 敗。因此針對不同鋁合金成份須有各自特別的酸清洗浸潰溶液，甚至同一 種合金經熱處後亦會有所差異。即使僅是顯微結構之不同其酸洗行為也會 有很大的差異。由於要得到一均勻性佳的鋁材表面，酸浸潰的目的主要在 使表面非鋁元素得以去除，同時將鑄件表面之鋁_矽共晶組織侵蝕掉，使鋁 合金鑄件表面去合金化與孔洞化。在侵蝕期間對於鋁材本身不能有太多侵 蝕情形，因HNO3對鋁的腐蝕速度較慢，因此在酸洗時與其他酸液搭配， 形成一種抑制劑，可以使得鋁材不被侵蝕過多。以為主體的酸浸潰 液’依據所要處理鋁合金材質的不同添加適當的HF及h2S〇4等，酸浸潰配 方以HF與邮〇4為主要反應成份，以HN〇3為抑制劑。HF的主要功能為 侵蝕Si元素，此反應是利用硝酸將矽表面氧化成二氧化矽，再利用氫氟酸 將形成的二氧化矽溶解去除，反應式如下：I247826 发明, invention description: [Technical field to which the invention belongs] Ben! X month is a kind of process to solve the problem of poor adhesion between the substrate and the coating. The surface of the aluminum alloy casting is de-alloyed and woven by HN〇3, HF, Ημ 2 〇4 bath etch. The person unloads the isopropyl-mixed solution to carry out the side of 7 so that the eutectic group such as L privately causes the surface of the prayer to be deeper; the bottom surface of the alloy casting after the electric ore is recorded with the root-like contact surface of the base tree. These tree-like contact surfaces are due to the side surface treatment, and the surface stones are left (4) vacant, providing a good environment for the attachment of the surface of the IS substrate to the surface of the coating. . Further, the present invention treats the residual towel in Shangyu, and has a special method to solve the problem of adhesion between the alloy and the coating. [Prior Art] Surface treatment of electric ore: The most commonly used method of L industry towel, the plating method is very wide, except for the electric clock can be applied to all kinds of metals, nowadays it has also developed on plastic power supply. mine. Because the equipment and operation of electric mines are more difficult to control and have a long history of development, they have a certain level of technology and are now widely used in the surface treatment industry. The standard reduction potential of aluminum is a negative value (Ε〇 = -1·67 ν), and we cannot perform the precipitation in an aqueous solution. Therefore, all the steps of the electroplating of the alloy are carried out in an organic electrolytic solution or a molten salt bath. Aluminum is an element of high oxidation potential in the periodic table, so aluminum is chemically replaced with a metal having a higher reduction potential. The order of oxidation potential of a common metal is: K > Ca > Na > Mg 1247826 > Al > Zn >Cr>Fe>Sn>Pb>H>Cu>Hg>Ag>Pt>Au yttrium aluminum is a chemically active metal, but maintains a beautiful luster in dry air for a long time, resulting in a colorless and transparent surface The protection of the oxide film. However, the thickness of the oxide film is only i 10 nm, which does not achieve sufficient corrosion protection. There are many kinds of aluminum alloys, because other alloying elements such as bismuth, magnesium, copper, etc. are often added to the strength and certain specific requirements. These components often cause unevenness on the surface of the plated parts, resulting in bad money. Fortune will remove this part from the surface to ensure the adhesion and continuity of the clock layer. When electroplating aluminum and its alloys, it is more difficult to electroplate than other metal materials. If it is applied to the electroplating of aluminum by ordinary electroplating on iron or copper, it can only temporarily protect the surface. When it is placed in the air for a long time, the recording layer tends to swell and peel off everywhere, and the mechanical properties of the electric ore layer are poor, and pinholes and other defects often occur. Compared with other metals, it is electrochemically positive, and if it has the above defects, it is easy to cause corrosion at this place and peel off the coating. The reasons for such defects can be summarized as follows: L is electrochemically positive 2. The surface is easy to form an oxide film 3. Aluminum is corroded by the electrolyte 4 · The inside of the metal and the plating layer are easy to form bubbles S · There are impurities in the aluminum 6 · Electroplated metal Alloy can not be formed with aluminum 1247826 7 · Electrolyte residual metal pores 8. Aluminum and electroplated metal thermal expansion coefficient Electroplating refers to the reduction of metal ions on the surface of the object by electroplating in a plating bath. The operation of metal atoms and growing into a coating. The end where the reduction reaction is carried out in the plating bath is called a cathode, and the end where the oxidation reaction is carried out is called an anode (Anode); the medium for performing the above reaction is called a plating solution, which is composed of electrolyte, water and some necessary Composition of ingredients. The process of the electric key can be roughly divided into five steps of polishing, pretreatment, electroplating, after treatments, and drying. According to Faraday's law, the relationship between the amount of current and the amount of deposition obtained by electrolysis is 96500, where W is the mass of the participating reactants (in g), and 1 is the time of electrolysis operation by the amount of current (amperes). Second), the amount of charge in each of the e-tables involved in the reaction. Theoretically, the amount of Faraday's electricity should be 1 gram equivalent of atom, but in fact the plating precipitation is affected by the plating conditions and the plating bath. Usually, the current efficiency is less than 100%, so it cannot fully comply with the law. In general, electroplating is commonly used in electroplating with nickel plating, copper plating and chrome plating: (1) Nickel plating: It is commonly used for steel, brass, zinc and alloys. It can be used for side and anti-corrosion. The commonly used nickel ore is the Watts bath. It was developed 80 years ago and is easy to operate and maintain. The gamma 8 bath consists essentially of nickel and some vapors and Wei, _ is slow, and vapor 1247826 is used to promote anodic dissolution. The typical process is between 30-40 °C operating temperature, and the plating bath formula contains NiSCV7H2〇250g/l + NiCl2.6H2〇40g/l + H3B〇4 25g/b. The pH of the plating solution is about 5. 2-5. · The current density between 8 is 2-4 A/dm2. If the environmental corrosion used in the ore parts is not significant, the thickness of the bond layer is 8~13μηη; but in a highly corrosive environment, the thickness of the nickel plating layer must be 25~3〇μιη; on the plated parts, another 0.25~0· 50μιη thickness of chromium, can significantly extend the number of years of durability. (2). Copper plating: Copper is often used as an intermediate layer, which has a flat plating function and prevents natural displacement and ensures coating adhesion. The common plating bath formulation is a plating bath containing CuS〇4.5H2〇16〇_22〇§/1 and HAO4 50-75g/l at room temperature with a current density of 2~4 A/dm2. In general, the process requires a relatively high copper content and sulfuric acid is used to reduce the solubility of copper sulfate, so the copper content should not be too high to cause crystallization. The effect of sulfuric acid on the solubility of copper sulfate, the lower the concentration of sulfuric acid, the greater the solubility of copper sulfate. (3). Chrome plating: In order to improve the corrosion resistance of Ming and its alloys, the plating parts are often chrome-plated; at the same time, the wear resistance of chromium is large. When the alloy is used for axles, if the part of the contact bearing is chrome-plated, It has the same degree of wear resistance as steel bearings. The commonly used chrome plating formula is Cr〇3 4〇〇 g/1 + H2S〇4 4 with an operating temperature of 40-50 ° C and a current density of 3〇_8〇A/dm2. Generally, the sau alloy is subjected to grinding, degreasing, acid leaching, zinc replacement (zinc strontium treatment), electric ore and post-treatment, from the finished material to the plating. The degreasing and acid leaching of strontium sulphide is replaced by the pre-treatment process, the effectiveness of electroplating bismuth alloy plating in this step. 1247826 Xizhiming alloy money by zincate treatment of the age of the alloy according to the wrong, generally. β washing - 瘵 ru method to remove oil or solvent degreasing - alkaline solution cleaning - cleaning - pickling - cleaning - zincate treatment - Cleaning - double cleaning ~ plating. The defects of electric ore produced by incomplete treatment are: 1. The coating will peel off or generate bubbles. 2. Electroplating has irregularities and small holes. 3. Corrosion resistance of electroplated products is reduced due to the generation of bubbles. 4. Electroplating layer embrittlement 5. Gloss Non-uniform and 8G% of the non-performing rate of electric ore is caused by poor pre-treatment. Therefore, when electroplating is performed, it is more difficult to electroplate than other metal materials. The main reason is that it occurs in aluminum. The adhesion between the material and the plating layer is poor, and the plating layer is easily peeled off. SUMMARY OF THE INVENTION Electroplating of aluminum alloy castings has always been a difficult process. Because the inner part of the aluminum alloy casting contains holes, the Wei hole will be exposed after the aging. Although the plating will cover the past, the hole contains the rolling body. After the mine, there will be blisters (sinful and heavy). On the other hand, the composition of the surface of the aluminum alloy casting itself is extremely uneven, often making the pretreatment process impossible. There are two improvement methods. One is to improve the aluminum alloy casting process to reduce or completely eliminate the porosity of the casting. Another solution is effective acid immersion. After effective pickling, a casting surface with good uniformity and suitable for electroplating can be obtained, so that the surface of the complicated 1247826 aluminum alloy casting can be electroplated. The invention patent mainly solves the problem of poor adhesion between the aluminum substrate and the plating layer, and provides a method for solving the problem in this aspect. Generally used aluminum alloys for casting are mostly aluminum _ 矽 eutectic materials. When the hypoeutectic aluminum 矽 alloy is solidified, the primary phase (primary aluminum) is formed first, when the concentration of the melt reaches the eutectic composition. That is, an aluminum-germanium eutectic structure is formed. The shape, size and distribution of the eutectic enthalpy are mainly influenced by factors such as alloy composition, solidification rate and quenching and tempering. Adding a trace amount of elements such as strontium (Sr), sb (Sb) or nano (Na) to the aluminum alloy will cause the original acicular or plate-like eutectic enthalpy to passivate and transform into a rounded structure, thereby improving the machinery. nature. When the aluminum alloy is exposed to an oxygen-containing atmosphere, an eight 12 〇 3 oxide film is formed in an instant, and if the oxide film is given sufficient time and an appropriate temperature, the Al 2 〇 3 oxide film is converted from an amorphous to a crystalline body. Since the diffusion rate of yttrium 3 is much faster in the crystal than in the amorphous, the oxide film of the crystal will settle down and no longer oxidize. The material promotes the transformation of the amorphous oxide film into a crystal, and Mg promotes the formation of MgO in the alloy. In particular, in an aluminum alloy having a content exceeding 5% by weight, since the surface energy of MgO is lower than that of A1203, a compound is preferentially formed. When MgO enters the Al2〇3 film, MgAi2〇4 (magnesium aluminum spinel) is formed, and its crystallization power is higher than that of a12〇3. From the above, it is known that the surface structure of a commonly used aluminum alloy casting for casting is a primary crystal aluminum and an aluminum-ruthenium eutectic structure, and an outer surface of the surface is oxidized to form an oxide film of erbium 2 〇 3 or MgAl 2 〇 4 . As shown in Fig. 1, it is the metallographic section of the plated part of the general factory. It is obvious that the joint surface of the plating layer and the machine material is smooth, and there are many defects of the crucible. The smoothness of the joint surface reduces the adhesion, and the joint surface 1247826 exists. The flaws will form the beginning of the coating to break off. According to the electroplating process used in the electroplating factory, the inscriptions and gold scales have produced a large number of bubbles under the quenching of 2(), indicating that the adhesion of the electroplated test pieces is extremely poor and cannot be tested by Wei Jialin. The metallographic structure is observed in the section where the oxygen layer is generated in the ore layer. It can be seen from Fig. 2 that the shovel layer rupture is from the part of the surface containing the tree element to the time ship, and these are not invaded. Wang's cockroaches could not be replaced with the ionic ions, thus causing some small pits on the surface with a stone surface. During the electroplating, some non-reactive pits and plating could not be effectively bonded tightly, so that the hydrogen generated during electroplating remains in it. towel. These residual (four) hydrogens swell, and they will expand from the joint surface to produce bubbles that are seen on the giant. The invention patent mainly relates to the surface pretreatment of the aluminum alloy casting for casting in the electric ore processing process, and the oxide film of Al2〇3 or MgAl2〇4 is removed on the surface of the prayer piece, and the surface of the gold casting is removed on the surface by the touch of the liquid. Alloying and hole formation, and then put a mixture of hydrogen hydroxide and isopropyl alcohol; ^ secret engraving, so that the eutectic _ tissue # engraved deeper, resulting in casting surface hole / the same deeper in the process of making electricity! The adhesion between the surface of the substrate and the bond layer is as shown in Fig. 3. After the surface treatment of the lion surface of the invention is carried out, the metallographic section of the coating layer of the Wei process is performed, and there is a plurality of roots between the nickel and the substrate. The contact surface, the root-like contact of these trees is due to the surface of the money engraving; the vacancy left by the component is invaded, providing a good environment between the coating and the substrate. [Embodiment] The process of casting the key of casting alloy is shown in Figure 4. The process parameters are shown in Figure 5. Before the electric ore 11 1247826 treatment process, the aluminum alloy castings are first placed in a degreasing solution at 50-60 ° C for chemical treatment. Degreasing procedures, because of the high chemical activity of the Ming, the surface of the oxide film formed in the air has a protective effect. However, the oxide film will be able to contain NaOH' § When the metal surface is in direct contact with the solution, the aluminum is easily invaded, and hydrogen is not generated during the oxidation of the oxide film. However, when the aluminum is invaded, a large amount of hydrogen is generated. The following formula: 2Al+2Na0H+2H20-^2NaA102+3H2 The degreased test piece is washed with water twice and then placed in an acid washing solution for acid immersion. There are many added alloying elements on the surface of the aluminum alloy. These elements are not It will be replaced with zinc. If this is done directly, the surface replacement layer will be discontinuous, which will lead to the failure of electroplating. Therefore, different aluminum alloy components must have their own special acid cleaning impregnation solution, even after the same alloy is heated. Even if only the microstructure is different, the pickling behavior will vary greatly. Since the surface of the aluminum material with good uniformity is obtained, the purpose of acid leaching is mainly to remove the non-aluminum element on the surface, and at the same time, the aluminum 矽 eutectic structure on the surface of the casting is eroded to de-alloy the surface of the aluminum alloy casting. Hole hole. During the erosion, there is not much erosion of the aluminum itself. Because HNO3 corrodes aluminum slowly, it is combined with other acids during pickling to form an inhibitor that can prevent the aluminum from being excessively eroded. The acid leaching solution of the main body is added with appropriate HF and h2S〇4 depending on the material to be treated. The acid leaching formula is mainly composed of HF and Mail 4, and HN〇3 is used as an inhibitor. The main function of HF is to erode Si. This reaction is to oxidize the surface of cerium to cerium oxide by nitric acid, and then dissolve the formed cerium oxide by hydrofluoric acid. The reaction formula is as follows:
Si + HN〇3 + 6HF + H2SiF6 + HN〇2 + h2 + h2〇 12 1247826 雖然-次的辞酸鹽處理可以將崎表面沈積—層鋅披覆，但兩次的鋅酸 鹽處理使得置換層有較好_著性。經過第—次鋅酸鹽處理_件經過水 洗與硝酸㈣浸潰後再重複—次辞賴處理’所制的置換表面將更細 緻附著性更佳。經鋅酸鹽處理後之鑄件均可利用鋅與其他金屬之親和性 來電鍍其他金屬。由於辞層㈣，若欲電鑛金子穿透鋅層而侵餘底層 之鋁材，則易產生電鍍層的不良沈積。 置換成後亦需再兩次水洗，至此步驟為第一次辞置換的程序。第二次 置換乃重複酸浸潰與鋅置換的步驟，每個步驟間仍須有兩次水洗，即可完 成前處理製程。 前處理製程完成後與一般鋼鐵電鍍製程相同，經過鋅酸鹽處理的待鍍 件，先經過鍍鎳的打底鍍層製程，接著利用鍍銅將鍍層面平整化，然後再 錄上鎳層防餘，最外層再鑛上薄薄的一層鉻可以增加耐餘並具有表面裝飾 性的功能；一般鋁合金電鍍鍍層的厚度分別為3μιη的底鎳層，7μπι的銅鍍 層，30μ的防蝕鎳層與的表面鉻鍍層。 為了確為刖處理與電鑛層的效果，並以Cambridge Instrument S-360掃描 式電子顯微鏡(SEM)觀察’並利用GDS(Glimm Discharge Stectrometer)分光 儀對試片表面做成份分析，觀察鑄件表面成份變化與深度的關係。為了確 認紹基材表面與鍍層間之附著性的效果，鑄件電鍍完成後，依照JISH8504 電鑛品質規範之規定，將電鍍完之鋁合金鑄件利用熱空氣循環爐加熱，維 持一段時間後迅速淬至入水中急冷。鋁合金所規定的檢驗溫度為2〇〇°C，因 1247826 此訂定加熱溫度為2〇〇t做淬火 驗做比較，维斜qn、 、♦兩組加熱靴、靴的試 維持時間疋為30分鐘、60分鐘、12〇分 鍍件密著情形。 H刀鐘。嬈察其 人太圖6可知銘合金鑄件表面經取〇3、取、设邶溶液侵制方式將紹 口物件表面去合金域細化，再放人氫氧化鉀與異丙_混合溶液進 树的鄉使共晶雜織侧更深入，表面絕大部份神都賺乾淨， 留下許多原為共晶獨制，由於表面的凹凸不均，用—般光學顯微鏡無 法仔細看恤職的表面形態，掃㈣子__可以看出試片表面 般的崎囉不平，這些南南低低的凹洞原本是石夕元素，受钱刻後所留 下的空缺孔洞。 由電子顯微鏡峨察，侧後的試#初始職為祕絲面含有大小不 一的坑洞，在鋅酸鹽處理初期，表面的鋁與辞離子產生置換而沈積，由於 表面不是平整的，所以顯微鏡下所看到的表面組織除了鋅的沈積外，還有 少數凹陷的坑洞（如圖7);隨著作用時間的增長，鋅離子還原而持續沈積， 鋅的晶粒漸漸成長並會把坑洞填滿（如圖8)。 利用GTS分光儀，對蝕刻後的試片進行分析得到一試片含^、Mg、A1 量與深度的分布曲線圖，如圖9所示，矽元素的成份在距表面為最低；距 表面3nm以内的矽含量都在2%以下，之後隨深度之增加，矽含量亦隨之增 加，在距表面10 nm後矽含量即不再有任何改變。 電鍍後鋁合金鑄件截面的鍍層金相組織觀察顯示底層鎳與基材間 15 1247826 有α午夕樹根狀的接觸面’如圖3所示，這些樹根狀的接觸是因為蝕刻 處理叶表面矽成份被侵蝕所遺留的空缺，提供了鍍層與基材間的良好 密著環境。為了與本發明專利之前處理製程做一比較，亦利用一般電 鍵工薇使用之前處理方式進行電鍵製程，如圖1即是工廠所電鑛的鍵 層截面金相，明顯看出鍍層與機材的接合面較為平滑，並有許多矽的 殘留’接合面的平滑會降低_力，而接合表面存在㈣會形成鑛層 破壞剝落的開端。 電鍍完畢的銘合金鑄件利用熱空氣循環爐分別做·。c、25(rc、 30(TC的加熱溫度，配合Q. 5小時、丨小時、2小時與4小時的加熱時 間後進行淬火實驗，其結果如圖1〇所示。在2GG°C加熱下，試片在2 小時内並絲泡產生，在4小喊會有少數的微小氣紐生，但不十 刀顯著。右溫度提高至25〇t，在2小時加熱後試片仍未有氣泡產生 之現象，不過在4小時的加熱後，舰内部份小氣泡受熱膨脹而對鍛 層產生向外舰的壓力，_有些許錢泡之產生。若是加熱至· °C來作淬火實驗’在2小時後已有小_生成，到4小時加熱後某些 部位未排出的氫氣受到高熱膨脹對鍍層擴張產生較大的氣泡。 【產業上利用之可能性】 本發明中可極纽率地針鱗造雜合錢件在製財表面前處 理’進行鑄件表面去除Al2〇3或MgAl204之氧化膜，μ表面以勵3、 I247826 Ήρ、H2s〇4溶液侵蝕的方式將鋁合金鑄件表面去合金化與孔洞化，再放入 氫氣化鉀與異丙醇的混合溶液進行矽的蝕刻，使共晶矽组織蝕刻更深入， 造成鑄件表面孔洞更深，以提高電鍍製程中鋁基材表面與鍍層間之附著性; 利用本發明中之製造方法可間歇生產、連續生產及大量生產鋁合金鑄件電 鍍製程。Si + HN〇3 + 6HF + H2SiF6 + HN〇2 + h2 + h2〇12 1247826 Although the treatment of the acid salt can be applied to the surface of the surface, the zinc coating is applied to the replacement layer. Have a good _ sex. After the first-thin zincate treatment, the replacement surface after the water-washing and nitric acid (four) impregnation is repeated, the replacement surface is more finely adhered. Castings treated with zincate can be used to plate other metals with the affinity of zinc for other metals. Due to the layer (4), if the gold ore is required to penetrate the zinc layer and invade the aluminum material of the bottom layer, it is easy to cause poor deposition of the plating layer. After the replacement, it is necessary to wash the water twice more, and this step is the procedure for the first replacement. The second replacement is a step of repeating acid impregnation and zinc displacement, and two steps of water washing are required between each step to complete the pretreatment process. After the pre-treatment process is completed, it is the same as the general steel electroplating process. The zincate-treated part to be plated is first subjected to a nickel-plated primer plating process, then the plated layer is flattened by copper plating, and then the nickel layer is retouched. A thin layer of chrome on the outermost layer of remineralization can increase the tolerance and have a surface decorative function; generally, the thickness of the aluminum alloy plating layer is 3 μm of the bottom nickel layer, 7 μπι of the copper plating layer, 30 μ of the anti-corrosive nickel layer and Surface chrome plating. In order to confirm the effect of bismuth treatment and electric ore layer, and observe it with Cambridge Instrument S-360 scanning electron microscope (SEM) and analyze the surface of the test piece by GDS (Glimm Discharge Stectrometer) spectrometer, observe the surface composition of the casting. The relationship between change and depth. In order to confirm the adhesion between the surface of the substrate and the coating, after the casting is completed, the electroplated aluminum alloy castings are heated in a hot air circulation furnace according to the JISH8504 electric ore quality specification, and then rapidly quenched until after a period of time. Quenched into the water. The inspection temperature specified by aluminum alloy is 2〇〇°C, because 1247826 is set to be 2〇〇t for quenching and comparison, and the test holding time of the two sets of heating boots and boots is 30 minutes, 60 minutes, 12 minutes of plating is tight. H knife clock.娆 其 其 太 太 太 图 图 图 太 图 铭 铭 铭 铭 铭 铭 铭 铭 铭 铭 铭 铭 铭 铭 铭 铭 铭 铭 铭 铭 铭 铭 铭 铭 铭 铭 铭 铭 铭 铭 铭 铭 铭 铭 铭 铭 铭 铭 铭 铭 铭The township makes the eutectic weaving side deeper, and most of the surface is earned clean, leaving many of the original eutectic, due to the uneven surface, the surface can not be carefully watched with a general optical microscope. Form, sweep (four) __ can be seen on the surface of the test strips like rugged, these low-lying recesses in the south and south are originally Shi Xi elements, the vacant holes left by the money carved. Observed by electron microscopy, the side of the test # initial job for the secret silk surface contains pits of different sizes, in the initial stage of zincate treatment, the surface of the aluminum and the word ion replacement and deposition, because the surface is not flat, so the surface is not flat, so The surface structure seen under the microscope, in addition to the deposition of zinc, has a few pitted pits (Fig. 7); as the time of application increases, zinc ions are reduced and continue to deposit, and the crystal grains of zinc gradually grow and will The pothole is filled (Figure 8). Using the GTS spectrometer, the etched test piece was analyzed to obtain a distribution curve of the amount, depth and depth of a test piece containing ^, Mg, and A1. As shown in Fig. 9, the composition of the lanthanum element was the lowest at the distance from the surface; The content of niobium is less than 2%, and then the niobium content increases with the increase of depth. After 10 nm from the surface, the niobium content no longer changes. The metallographic structure of the coating of the aluminum alloy casting after electroplating shows that the bottom surface of the nickel and the substrate is 15 1247826. There is a contact surface of the amber tree root as shown in Fig. 3. These tree-like contacts are due to the etching of the leaf surface. The vacancy left by the erosion of the ingredients provides a good adhesion between the coating and the substrate. In order to compare with the pre-treatment process of the present invention, the general key switch is also used to perform the key-bonding process using the previous processing method. As shown in FIG. 1, the key layer metallographic phase of the factory is the electro-mineral bond, and the bonding between the plating layer and the machine material is apparent. The surface is smoother and has a lot of crucible residue. 'The smoothness of the joint surface will reduce the _ force, and the presence of the joint surface (4) will form the beginning of the mineral layer damage flaking. The electroplated Ming alloy castings are made separately using a hot air circulation furnace. c, 25 (rc, 30 (TC heating temperature, with Q. 5 hours, 丨 hours, 2 hours and 4 hours of heating time after the quenching experiment, the results shown in Figure 1 。. Under 2GG ° C heating The test piece is produced within 2 hours and the silk bubble is generated. There will be a small number of tiny gas newborns in the 4 shouts, but not so. The right temperature is increased to 25〇t, and the test piece still has no bubbles after 2 hours of heating. The phenomenon occurs, but after 4 hours of heating, the small bubbles inside the ship are heated and expanded to produce pressure on the forged layer to the outer ship. _ Some money is generated. If it is heated to °C for quenching experiment' After 2 hours, there has been a small _ generation, and after 4 hours of heating, the hydrogen which is not discharged in some parts is subjected to high thermal expansion to generate large bubbles for the expansion of the plating layer. [Industrial Applicability] The present invention can be extremely expensive The needle scales are mixed with the money on the surface of the production surface. The surface of the casting is removed from the oxide film of Al2〇3 or MgAl204, and the surface of the μ is de-alloyed by the etching of the solution of the 3, I247826 Ήρ, H2s〇4 solution. And hole formation, then add a mixture of potassium hydride and isopropanol The liquid is etched to make the eutectic ruthenium structure deeper, resulting in deeper holes on the surface of the casting to improve the adhesion between the surface of the aluminum substrate and the plating layer in the electroplating process; the manufacturing method in the invention can be intermittently produced and continuously Production and mass production of aluminum alloy casting electroplating process.
17 1247826 【圓式簡單說明】 圖1 -般卫薇所電鍍的騎之實體鍍層截面金相，_看出鍍層與機材 的接合面較為平滑，並有許多矽的殘留，接合面的平滑會降低附著 力。 圖2 —般工廠所電鍍的鍍層之實體鍍層截面金相，鍍層破裂是從鋁基地 表面含有矽元素的部份開始向兩旁擴張。 圖3本發明專利的表面前處理方法處理後，進行電鍍製程之實體鍍層截 面金相。 圖4本發明專利的鑄造用鋁合金鑄件電鍍流程。 圖5本發明專利電鍍製程的製程參數。 圖6紹3金每件表面經HN〇3、HF、H2S〇4溶液侵鍅的方式將紹合金鑄件 表面去合金化與孔洞化，再放入氫氧化鉀與異丙醇的混合溶液進行 石夕祕刻，使共晶石夕組織姓刻更深入，絲絕大部份的石夕都已侵蝕 乾淨，留下許多原為共晶矽的坑洞。 圖7辞酸鹽處理初期，表面的銘與辞離子產生置換而沈積，由於表面不 疋平整的，所以顯微鏡下所看到的表面組織除了鋅的沈積外，還有 少數凹陷的坑洞。 圖8隨著辞酸鹽處理作用時間的增長，辞離子還原而持續沈積，辞的晶 粒漸漸成長並會把坑洞填滿。 圖9利ffiGTS分光儀，對侧後的試片進行分析得到—試片含石夕與麟量與 18 1247826 深度的分布曲線圖。 圖ίο鋁合金鑄件利用熱空氣循環爐進行淬火實驗。17 1247826 [Simplified circular description] Figure 1 - Metallographic section of the physical plating of the plating plated by Weiweiwei, _It is seen that the joint surface of the plating layer and the machine material is smooth, and there are many defects of the crucible, and the smoothness of the joint surface is reduced. Adhesion. Figure 2 shows the physical phase of the plating of the plating plated in the factory. The rupture of the coating starts from the part containing the strontium on the surface of the aluminum base and expands to the sides. Fig. 3 shows the metallographic cross-section of the physical coating of the electroplating process after the surface pretreatment method of the present invention is processed. Figure 4 is a plating process for casting aluminum alloy castings of the present invention. Figure 5 shows the process parameters of the electroplating process of the present invention. Fig. 6 The surface of each of the 3 gold is de-alloyed and holed by HN〇3, HF, H2S〇4 solution, and then the mixture of potassium hydroxide and isopropanol is added to the stone. The secret of the eve, so that the eutectic stone eve organization name is deeper, and most of the stone eves have been eroded, leaving many potholes that were originally eutectic. In the initial stage of the acid salt treatment, the surface of the surface is replaced by the imprinting ions. Since the surface is not flat, the surface structure seen under the microscope has a few pitted pits in addition to the deposition of zinc. As shown in Fig. 8, as the time for the treatment of the acid salt increases, the reductive ions continue to deposit, and the crystal grains gradually grow and fill the pits. Fig. 9 is a ffiGTS spectrometer, and the test piece after the opposite side is analyzed. The test piece contains a distribution curve of the depth of the stone and the amount of 18 1247826. Figure ίο Aluminum alloy castings were quenched using a hot air circulating furnace.