本研究將含1wt% Cu之延性鑄鐵(Ductile iron, DI),經過沃斯回火熱處理後,形成銅合金化之沃斯回火延性鑄鐵(Austempered ductile iron,簡稱ADI),具有高強度、耐磨耗及低成本等優點,被廣泛應用在工業上;但因基地組織有球狀石墨 (Nodular graphite) 存在,導致表面的石墨坑洞使其性質劣化;為改善其性質,使用無電鍍鎳(Electroless nickel, EN) 作為中介層,並利用陰極電弧沉積技術分別披覆CrN、ZrN及(Cr,Zr)N多層膜,來探討銅合金化ADI經低溫複合表面改質之特性。 經鍍膜處理之試片利用SEM、XRD及TEM分析鍍膜形態及結構,並利用附著性檢測、硬度試驗、單顆沖蝕試驗、奈米壓痕試驗、磨耗試驗、極化腐蝕試驗及浸漬腐蝕試驗來探討膜層的性質,以了解銅合金化ADI經鍍膜前後之磨耗及腐蝕行為。經膜層形態分析結果顯示,EN是由Ni的微小晶粒及P組成之晶質與非晶質混合結構,經TEM確認後可知Ni(220)為其優選方向;而(Cr,Zr)N 為F.C.C結構之CrN/ZrN多層膜形態。經膜層性質分析可知,有EN中介層者,皆能使其性質提升;在硬度及磨耗方面,EN-ZrN具有最高硬度(1954Hv50g)及最低摩擦係數值(0.21);而在耐腐蝕性質則以EN-CrN為最佳,另EN-CrZrN多層膜則同時具有EN-ZrN與EN-CrN之特性,可得耐蝕與耐磨兼具之改質效果。
copper alloyed austempered ductile iron (Cu-ADI) has been widely applied in the industry because it has some dramatic advantages such as high strength, wear resistance, and low cost. However, the Cu-ADI’s surface from the phenomenon of the nodular graphite peeled off. Results in the deterioration of surface property. In this study, we used Electroless nicke (EN) as interlayer to avoid hole-defect on the surface, and then deposited CrN/ZrN multilayer by using cathodic arc deposition (CAD) technique. Coating morphology and structure were analyzed by using SEM, XRD, and TEM. Moreover Adhesion test, Solid particle erosion test, nanoindention test, wear test, polarization test, and immersion test were all performed for understanding coating properties. The results showed that EN is a mixed structure of crystalline and amorphous while the (Cr,Zr)N film is a multilayer type with a F.C.C structure. The EN-ZrN has the highest hardness and the lowest friction coefficient (0.21) . On the other hand , the EN-CrN has the best performance in corrosion resistance. In addition, the EN-CrZrN multilayer was wear and corrosion resistance; it was the best possesses both the functions of corrosion resistance and wear resistance.