Metallic glasses have been drawing increasing attention in recent years due to their scientific and engineering significance. Meanwhile, a large number of metallic glasses with high glass-forming ability have been found in many alloy systems. Compared to conventional metals and alloys, metallic glasses have superior properties such as high strength, hardness and elastic strain limit, along with relatively high fracture toughness, fatigue and corrosion resistance. Accordingly, they are considered as promising candidates for the next generation of structural materials. However, there are still some intrinsic disadvantages of metallic glass, which limit their large-scale industrial applications. A sufficiently high cooling rate is always required during casting in order to prevent the more thermodynamically stable crystalline phases from forming. Brittleness is another drawback for monolithic BMGs, which also limits their application as structural materials. Due to the absence of strain hardening, BMGs usually show a catastrophic fracture under mechanical loading, and the ductility of most of the BMGs is very limited. Therefore, there have been attempts to find other applications of metallic glasses for use as structural materials. One of them is to use the metallic glasses as reinforcements in metal matrix composites (MMCs). In traditional MMCs, the most widely used reinforcements are ceramics, such as Al2O3 or SiC. However, the interfaces between the ceramic reinforcements and the metal matrix are usually not good, which results in highly porous materials with reduced mechanical properties and increased corrosion sensitivity. In order to solve this problem, some special techniques, such as reinforcement coating and adjustment of the chemical composition of the matrix are used, which inevitably increases the cost of the MMCs without significantly improving their properties. The metallic glasses reinforcements, containing only metallic elements, are believed to be more compatible with the metal matrix and to result in better interface bonding than their conventional ceramic counterparts, such as Al2O3 or SiC. Therefore, they are considered to be potential substitutes for ceramic reinforcements in MMCs. In this study, we use a new method to produce metallic glasses particle-reinforced Al-based MMCs at a relatively low temperature. Ni–Nb-Zr metallic glasses particles are firstly prepared by mechanical alloying and they are then combined with pure Al as matrix by using powder metallurgy in order to fabricate a metal matrix composite powders. The successfully prepared amorphous/Al metal matrix composite powders will than be consolidated into bulk forms by using a uniaxial vacuum hot press machine. The structure and thermal property of as-prepared powders and bulk amorphous/Al metal matrix composite will be examined by XRD, SEM, TEM and DSC. In addition, the measurement of microhardness as well as potentiodynamic polarization on the bulk amorphous/Al metal matrix composite also will be conducted in order to understand the mechanical and corrosion property of the resultant bulk amorphous/Al metal matrix composite. After comprehensive evaluation of all the experimental results obtained in this work, the optimum conditions for the production of high performance bulk amorphous/Al metal matrix composite through ball milling and vacuum hot pressing routes also can be established. 近幾年來金屬玻璃受到各界廣泛的注意，金屬玻璃比傳統結晶態合金具有如高強度、高硬度，和高彈性限等較佳的性質表現，故相對也具有高破壞韌性、高疲勞、和高抗腐蝕性等特質，因此金屬玻璃被視為極具潛力的結構材料。 目前雖有許多具有高玻璃成形能力的金屬玻璃在合金系統中被發現，然而在鑄造過程中為避免產生穩定的結晶相，常需以較高的冷卻速度進行澆鑄，因此以鑄造方式可製造之最大金屬玻璃塊材亦僅止於 Zr-Ti-Cu-Ni-Be 合金系統的直徑約 75mm 大小，在其他合金系統甚至無法突破直徑五公分，而金屬玻璃塊材在工業上的應用因此也受到限制。另在單相塊狀金屬玻璃由於缺乏應變硬化的原因，因此遭受機械負荷時會有強烈的破裂情形，此亦會限制其於結構材料上的應用。最近有學者提出把金屬玻璃當作金屬基複合材料的強化相來改善金屬基複合材料的性質，啟發此構思之原因是在傳統金屬基複合材料中，最廣泛使用的強化相為陶瓷粉末如 Al2O3 或 SiC，但傳統的金屬基複合材料有一個嚴重的問題，陶瓷強化相和基材的界面鍵結不佳，導致機械性質降低且腐蝕敏感性增加，因而利用金屬玻璃粉末來取代陶瓷粉末，因其與金屬基複合材料的基地組成皆是金屬材料，此可望提升強化相和基材的鍵結能力，得到較佳的機械性質。綜上所述，本研究將以機械合金法製備 Ni60Nb20Zr20 金屬玻璃粉末，再利用真空熱壓技術製程進行 Ni60Nb20Zr20/Al 金屬基複合材料之合成，並探討在不同球磨時間以及不同熱壓持溫時間下所製備之 Ni60Nb20Zr20/Al 金屬基複合材料的機械性質和腐蝕性質研究。研究工作之進行是先利用高能量球磨機製備出 Ni60Nb20Zr20 金屬玻璃粉末，再將不同比例的金屬玻璃粉末添加入Al 純元素粉末後，再以高能量球磨機合成具金屬玻璃/Al 組成之複合材料粉末，最後再利用真空熱壓成型技術將此粉末製備成含金屬玻璃/Al 複合材料結構之 Ni60Nb20Zr20/Al 基複合材料塊材，所製備之Al 基複合材料粉末與塊材，除將依序以 X 光繞射儀、DSC 熱差分析儀、SEM 掃瞄式電子顯微鏡及 TEM 穿透式電子顯微鏡進行行分析及研究其微觀組織結構外，另亦針對 Al 基複合材料塊材進行微硬度及極化試驗，詳細評估所得數據資料，將可開發出應用高能量球磨及真空熱壓製程製備 Ni60Nb20Zr20/Al 基複合材料塊材的最佳化條件。
Al-based metal matrix composite
Metallic glass reinforcement
Vacuum hot pressing.