- 學位論文
ZrCuNbPdAl非晶質合金之常溫滾軋及滾軋接合之研究
Room-Temperature Rolling and rolled-bonding of ZrCuNbPdAl Metallic Glasses
摘要
鋯基非晶質合金具有優異的機械性質、抗磨耗性高等特性，但由於其常溫塑性變形能力及韌性較其他結晶材料要來的不佳，因此研究中常透過各種方法來改善其機械性質或熱性質，如添加微量元素、熱處理、熱軋、常溫滾軋等方法，都是為了用來提升性能使材料可以更容易在生活中被使用。 研究指出，常溫滾軋可使非晶質合金之機械性質提高，並保留其熱性質及熱穩定性。因此本研究選用熱性質及熱穩定性佳的ZrCuNbPdAl非晶質合金做為常溫滾軋研究的對象。探討不同軋延率對於非晶質合金之機械性質以及顯微結構之影響。 機械性質方面，隨著軋延率的提升，非晶質合金之硬度值略為提升。但在軋延率60%時合金之硬度值下降。依據顯微結構的觀察，軋延率20%~50%時，合金表面之shear band變多，但其長度較短，分佈較密集，shear band互相阻擋其前進方向。而在軋延率60%時，發現合金表面的shear band分佈較為分散，長度較長，且合金有裂縫的產生，為合金在軋延率60%時，硬度下降的原因。 本研究亦透過常溫滾軋使非晶質合金與銅薄片接合，探討接合材表面粗糙度以及接合材間硬度差對接合效果之影響，實驗中，選用不同表面處理法，以及表面處理對象進行滾軋接合。發現表面粗糙度以及接合材硬度差對於接合效果皆有影響。而接合後其硬度與基材相比有上升的趨勢，是因為滾軋接合過程中，非晶質合金受滾軋影響產生表面加工硬化。而接合後之非晶複材與常溫滾軋之非晶質合金相比，其硬度值相差不大，但其硬度壓痕附近出現環狀shear band是因為中間的銅薄片吸收部份的應力，而使非晶質合金不易受外力破壞。
關鍵字
none並列摘要
Zr-based bulk metallic glasses have excellent mechanical properties, higher attrition resistance characteristics, but its plastic deformation and toughness at room temperature are poor than crystalline materials, so the studies often through varieties of methods to improve its mechanical properties or thermal properties, such as adding trace elements, heat treatment, warm rolling, rolling at room temperature and so on, are to be used to improve the performance of the material can be used more easily in life. Therefore the ZrCuNbPdAl bulk metallic glasses have good thermal properties and good thermal stability are used in this study. The mechanical properties of amorphous alloys are improved by rolling at room temperature and retain their thermal properties and thermal stability. On the mechanical properties, hardness of amorphous increase with the increase of the rolling rate. However, the hardness of alloys are decreased when the rolling rate of 60%. Based on observation of the microstructure, when the rolling rate of 20% ~ 50%, shear bands of alloy surfaces are increase, but its length is shorter, intensive distribution, shear band stop its advancing direction from each other. when the rolling rate is 60%, shear bands of alloy surface distribution are more dispersed, the length is longer, and there are cracks in the alloy, Resulting in the hardness decline when rolling rate is 60%. The study also through rolling to bond the amorphous alloy with copper foil, to discuss the effects of the roughness of surface and the difference of material hardness on the bonding. In the experiment uses different surface treatments and surface treatment objects to roll-bonding. It found that surface roughness and the difference of hardness between the bonding material are influenced bonding effect. At the roll-bonding process, effect the surface hardening by rolling amorphous. The hardness are after bonding has s rising trend compared with the substrate. And the hardness are little difference between, the amorphous after bonding and the amorphous after rolling at room temperature. and the emergence of the annular shear band nearby indentation hardness is because the middle of a copper foil to absorb most of the stress, resulting in the amorphous alloy is less susceptible by external damage.