Effects of Coatings Thickness on the Structural and Mechanical Performances of High Entropy Alloy Nitride Films

鍍層厚度對高熵合金氮化薄膜微結構和機械性質的影響

劉志偉(Zhi-Wei Liu) ； 楊慶彬(Ching-Been Yang) ； 胡志中(Chih-Chung Hu) ； 林鈞晟(Jun-Cheng Lin) ； 曹中丞(Chung-Chen Tsao) ； 許春耀(Chun-Yao Hsu)

《中國機械工程學刊》 41卷1期 (2020/02) Pp. 21-28

摘要

Multi-element high-entropy alloys systems (more than five elements) are alloy with X (5 ＜ X ＜ 13) principal elements each possess an atomic percentage no more than 35%. This paper determines the coating thickness for the high-entropy alloy (HEAs) nitride films using reactive direct current magnetron sputtering, that are deposited on ceramic insert tools and glass substrates. Using equimolar AlCrNbSiTiV HEA target and Ar plasma and N_2 reactive gases. The coated nitride films are characterized using scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDS), transmission electron microscopy (TEM) and a nano-indentation technique. The TEM patterns show that the (AlCrNbSiTiV) N films have a simple face-center-cubic (FCC) structure. The (AlCrNbSiTiV) N films are homogeneous, very compact and adhere perfectly to the substrate. The films are uniform and dense, adhere perfectly to the substrate, the results of the Rockwell indentation test are categorized as HF1. The experimental results show that after cutting, the coated tool has a minimum flank wear of 16.91 μm and a surface roughness Ra of 3.79 μm for a sputtering time of 25 min and a film thickness of 431 nm. When the coating thickness exceeds 431nm the elastic recovery and the hardness of the (AlCrNbSiTiV) N film increases However, further increases in the coating thickness results in a decrease in the cutting qualities.

關鍵字

high entropy alloys ； film thickness ； cutting performance ； nano-indentation ； direct current magnetron sputtering

並列摘要

本文採用反應性直流磁控濺鍍，製備高熵合金氮化物薄膜於於瓷金刀具，不銹鋼及玻璃基材。等莫爾AlCrNbSiTiV高熵合金靶材，Ar等電漿氣體，N_2反應氣體，探討不同高熵合金氮化物薄膜厚度（改變沉積時間），對薄膜微結構，機械性質及鍍層刀具切削行為的影響。氮化物薄膜應用掃描電子顯微鏡（SEM），能量色散X射線分析（EDS），穿透式電子顯微鏡（TEM）和奈米壓痕技術進行表徵分析。由TEM圖顯示，（AlCrNbSiTiV）N薄膜具有簡單的面心立方（FCC）結構。研究結果顯示，薄膜均勻且緻密，完美地粘附在基材表面。經洛氏壓痕測試，結果顯示氮化物薄膜為HF1優良等級附著性。鍍層刀具切削加工實驗結果顯示，薄膜沉積時間25分鐘（薄膜厚度為431 nm），有最小的刀腹磨損量16.91 μm，切削加工件表面粗糙度（Ra）為3.79μm。當鍍層厚度高於431 nm 時，（AlCrNbSiTiV） N薄膜的彈性恢復量及薄膜硬度有增大的趨勢，但是當鍍層厚度進一步增加，會降低切削加工品質。