金屬基複合材料之磨削性研究

Abstract

由於金屬鋁基複合材料的使用範圍廣泛，精密加工的需求也日益增加，但對金屬鋁基複合材料的磨削加工特性了解仍然未作深入的探討。金屬鋁基複合材料是由軟的鋁基底包含硬的陶瓷顆粒，其材料特性不單純是延性材料，既黏又硬，屬於複合式的材料，本研究嘗試並尋求有效且符合經濟效益磨削金屬鋁基複合材料的方法。本文進行乾磨削、一般切削液、MQL和使用液態氮作為切削液磨削金屬鋁基複合材料的研究，並比較在不同的切削深度和砂輪速度之下，各種切削液供給方式對砂輪填塞、黏屑機制、工件表面品質、磨削力和表面粗糙度的差異性並分析。實驗結果發現使用MQL時，由於高壓空氣的穿透力可以發揮出潤滑的效果，使得切削力下降，磨粒能保持住刃邊，砂輪磨耗量相對乾磨削及濕磨削小。噴液態氮最可以有效的降低砂輪的磨耗及填塞，並提昇材料的磨削性，可以獲得到比使用MQL更好的工件表面品質和較佳的表面粗度。而在使用液態氮時，可以增加磨削加工時砂輪的修整週期，提高加工的效率，並得到較為平整的工件，獲得更好的加工品質。

Due to the development and application of aluminium-based metal matrix composites extensively, precision machining demand also day by day increases, but reports on grinding of aluminium-based MMCs are still scarce. Aluminium-based MMCs are soft aluminum base including the hard ceramic reinforcements. Its materials behavior not only is ductile, but both sticky and hard. This research attempts and seeks to the economic grinding aluminium-based MMCs method. The contents of this article chiefly explain the effects on grinding aluminium-based MMCs when using liquid nitrogen, the general water-based fluid, the minimum quantity lubrication (MQL) and no cutting fluid.Under different cutting depth and grinding speeds, compare and analyze the differences when using liquid nitrogen, the general water-based fluid and no cutting fluid through the usage of wheel loading and wear, grinding force, surface of workpiece and roughness, also to analyze the diversification. The conclusion of this experiment is that using MQL can lubricate due to the more efficient penetration of the fluid into the cutting region, cause the cutting force to drop, be attributed mainly to the retention of the sharpness of the grits. The grinding wheel wear are relative to dry grinding and the wet grinding smaller. Using liquid nitrogen is the most effective to reduce wheel wear and loading, and is most prone to achieve better surface of workpiece and roughness than MQL grinding. When using liquid nitrogen, we acquire a flatter workpiece in order that we could economize the finished cost and to enhance efficiency.