摩擦式鋸削之毛邊形成模式研究

Abstract

摩擦式鋸削是高速鋸削的一種，利用鋸片高速旋轉使工件與鋸齒接觸部分，因摩擦熱熔解而切斷；摩擦式鋸削由於加工速度很快，廣泛應用於棒材、管材等的製造過程，但其切斷面往往因殘留極大的毛邊，需要二次加工修整，提高了加工成本，如欲改善這些現象就必須了解摩擦式鋸削之毛邊生成模式。 本研究以實驗的方式，探討摩擦式鋸削過程中鋸片線速度與鋸削溫度之變化對工件切斷面造成的影響，並由鋸削過程工件切斷面的高速攝影，配合金相顯微組織的觀察，進而闡明摩擦式鋸削的毛邊形成模式。 由實驗結果顯示，摩擦式鋸削切斷模式，先從切斷型態再逐漸轉為熔斷型態，被移除之材料除了形成切屑帶走熱量外，還會部分黏著在切斷面上再被鋸齒切離，造成切削阻力上升，使得鋸片線速度下降。並由鋸削過程熔斷所占比例的逐漸增加，導致毛邊會黏附在工件切斷面底緣。

Friction sawing is one of the sawing process that uses a very high speed rotating round blade to cut the workpiece. During the sawing process, melting of the workpiece occurred because of the severe friction between the cutting blade and the workpiece. Friction sawing though can cut the workpiece off very fast, however, very often a large piece of burr will leave on the cut off face and need further machining to clear it . In the study, we will investigate the effects of blade line speed and sawing temperature on cut off surface of workpiece. And we can from the high speed photograph of the process,match up the photomicrograph of the cut off face, define the burr forming process of the friction sawing. It is found that the friction saw cutting process transform the cutting type into melting type , the cut-off materials not only form the chips to bring the cutting heats, but also adhesion on cutting face and then let the cutting forceincrease make the blade line speed drop. And the percentage of melted down is increasing in the sawing process, making the burr adhesion on the bottom of the cut off face.