鍍層CrTiSiN複合薄膜模具之溫間機械性質及磨潤特性且應用於鎂合金溫間接觸分析

The Warm Mechanical and Tribology Property of CrTiSiN Composite Film of Die and Application to The Contact Analysis for The Magnesium Alloy

鄧吉宏(Ji-Hong Deng)

指導教授 ： 楊東昇

共同指導教授 ： 張銀祐(Yin-Yu Chang)

國立虎尾科技大學/工程學院/機械與電腦輔助工程系碩士班/碩士(2014年)

摘要

硬質鍍膜技術已廣泛應用於切削、成形模具等機械製造業，藉此來改善其磨耗特性、提高模具的壽命及降低生產成本，市面上以氮化鈦(TiN)、氮化鉻(CrN) 及氮化鋁鈦(TiAlN) 最為常見，氮化鈦相較於氮化鉻，具有較高的硬度，故多用於改善切削刀具的切削性能及增加使用壽命；而氮化鉻雖然硬度不及氮化鈦，但在附著力、摩擦係數及抗氧化能力皆優於氮化鈦薄膜，薄膜多應用於金屬成形模具。氮化鉻鈦矽(CrTiSiN)複合薄膜在溫間具有低摩擦係數、高硬度及良好的耐磨耗特性，另外，鎂合金之高強度及重量輕等優點，使得其用途越來越廣泛，由於鎂合金其溫間成形性較佳，故為了提升模具在溫間的模具壽命，以及降低磨耗、摩擦係數為目的，探討溫間模具與薄膜之機械性質為近年來學者與業界努力的方向。
本研究使用陰極電弧沉積技術製備CrTiSiN複合薄膜，以掃描式電子顯微鏡探討薄膜附著性及薄膜結構，之後使用有限元素分析法結合溫間奈米壓痕實驗，求得溫間CrTiSiN複合薄膜之彈性係數、硬度、溫間應力-應變曲線。其次，經溫間摩擦試驗機獲得複合層模具與鎂合金板材於石墨潤滑下之摩擦係數，觀察溫間CrTiSiN薄膜與鎂合金之粗糙比，並與TiAlN薄膜比較。最後，以溫間磨耗試驗機，判斷不同鍍層在溫間下之耐磨耗性及求得磨耗量與磨耗深度，並與業界常用之氮化鋁鈦薄膜比較。
由實驗結果得知SKD61模具鋼，經過陰極電弧沉積系統鍍製CrTiSiN複合薄膜，硬度、耐磨耗性、摩擦係數有明顯的改善，其中CrTiSiN薄膜在300℃硬度最高，其值為32.6 GPa，耐磨耗方面，常溫、高溫磨耗試驗結果CrTiSiN比TiAlN耐磨耗，摩擦試驗方面，CrTiSiN模具與鎂合金做純粹壓平與滑動接觸後其鎂合金粗糙度皆比TiAlN低 ，由以上結果可顯示鍍上CrTiSiN薄膜能有效的降低摩擦係數，並改善表面耐磨耗性。

關鍵字

硬質鍍膜 ； 陰極電弧沉積 ； 溫間奈米壓痕 ； 機械性質 ； 溫間磨耗 ； 有限元素分析

並列摘要

Hard coatings are adopted in cutting and forming application for a long time. The major purpose of hard coating is causing the smooth surface, increasing the strength and toughness of film, and reducing the friction coefficient. In the other hand, vacuum technology is important to apply in vacuum coating, like metal and ceramics films. Thus it can be seen that coating technology must be developed fast in short-time to resist the international competition. Moreover, the advantages of the higher intensity and lighter weight of magnesium alloy have made it more popular and more widely used because the warm-forming quality of magnesium alloy is better. As a result, in order to heighten the life of dies in the warm temperature and reduce their ware and friction coefficient, it has recently become the target for scholars and the industry to explore the mechanical properties of thin film of die.
In this study, a cathodic arc evaporation process is used to deposits the composite-layered CrTiSiN hard coatings. By using a cathodic arc facility equipped plasma enhanced reactive gas director, a dense composite-layered CrTiSiN hard coating is deposited. Field emission SEM is used to characterize the microstructure states of the synthesized films. This study applies the finite element method (FEM) in conjunction with warm nanoindentation test to predict warm bilinear stress-strain curve of film metal. The warm friction tests use CrTiSiN coating and TiAlN coating die such as compressing, compressing-sliding are carried out to investigate the variation of coefficient of friction and surface roughness of magnesium alloy sheet in this proposal. Then, use warm wear test measurements are used for wear resistance analyses.
According to the experimental results, SKD61 tool steel, a cathodic arc evaporation process is used to deposits the composite-layered CrTiSiN hard coatings, mechanical properties likes hardness and wear resistance as well friction coefficient has improved significantly. The hardness of CrTiSiN film of the highest value is 32.6 GPa at 300℃. In addition, the wear test results of CrTiSiN at normal temperature and high temperature are better than TiAlN. In the friction testing, CrTiSiN coating die with magnesium alloy make pure flatten and sliding contact. In the experimental results, the roughness of CrTiSiN coating die and magnesium alloy is lower than TiAlN. Through the above analytic results, it can be displayed CrTiSiN film and effectively reduce the friction coefficient and improved surface abrasion resistance.

並列關鍵字

hard coating ； cathodic arc evaporation process ； warm nanoindentation ； mechanical properties ； warm wear ； finite element analysis

參考文獻

[22] 陳得容，”陰極電流對TiSiN之磨潤性及相關特性之研究”，國立台北科技大學碩士論文，2010年。

[31] 許源泉，鍛造製程分析講義，國立虎尾科技大學機械製造工程系，雲林，臺灣。

[35] 林敬淶，”平行化分子動力模擬應用於奈米壓痕試驗”，國立暨南國際大學土木工程學系碩士論文，民國98年

[2] 林彥鈞，”陰極電弧沈績Cr(N,O)/CrN 複合鍍膜之氧化與腐蝕行為研究”，大同大學碩士論文，2004年。

[3] J.A. Sue and H.H. Troue,“Friction and wear properties of titanium nitride coating in sliding contact with AISI 01 steel”, Surface and Coatings Technology, Vol.43-44, 1990, pp.709-720.