合金元素對ZA27合金之微觀組織與機械性質影響

Effect of Alloying Elements on the Microstructures and Mechanical Properties of ZA27 Alloy

李喬心(CHIAO-HSIN Li)

指導教授 ： 黃和悅

共同指導教授 ： 郭央諶

國立虎尾科技大學/工程學院/材料科學與綠色能源工程研究所/碩士(2014年)

摘要

本研究將錫基合金添加至ZA27鋅鋁合金中，藉以探討錫基合金對其微觀組織與機械性質影響。不同錫基合金添加量(1、3、5 wt%)之ZA27合金，以光學顯微鏡和掃描式電子顯微鏡進行微觀組織觀察，結果顯示ZA27合金中添加少量錫，會細化初晶樹枝相且被共析α+η相所包圍；添加錫銅合金，微觀組織幾乎沒有改變，α枝晶仍是被較晚凝固的β相所包圍，最後是枝晶間凝固的η相和ε相。本研究也發現，添加錫基合金中含有鎂、鎳和鈷元素對微觀組織影響頗大，添加鎂會使η相由細枝狀轉變為棒狀，而添加鎳或鈷可以觀察到α枝晶相有變細的情形。最後，添加錫基合金的試片皆具有比ZA27合金具有更高的拉伸強度和維氏硬度值，而促使機械性質得到改善的原因，可能是形成β-Sn共析結構所造成。
關鍵詞:錫基合金、鋅鋁合金、合金元素、機械性質、微觀組織。

關鍵字

ZA27 ； 錫基合金 ； 機械性質 ； 微觀組織

並列摘要

In the present work, the influence of the tin-based alloys additions on the microstructural development and resulting mechanical properties of zinc-aluminium ZA27 alloy were investigated. Microstructure observations of ZA27 alloy with different tin-based alloys contents (1, 3, and 5 wt%) were performed by optical microscopy and scanning electron microscope. Microstructural examination showed that the ZA27 alloys with addition of a small amount of tin showed uniform distribution of fine particles with primary α dendrites surrounded by α+η eutectoid. When tin-copper alloy was added, the microstructure was not greatly changed, likewise presenting α dendrites which were surrounded by the subsequently solidified β phase, and the η and ε phases finally solidified in the inter-dendrite regions. Studies had also shown that the additions of alloying elements, such as Mg, Ni and Co, had a greater effect on the microstructure. The addition of Mg resulted in changed from fine dendrites to rod-like shapes in the η phase. In the case of Ni or Co addition, a fine dendritic microstructure of α-phase was observed. Finally, all of the specimens with tin-based alloys additions had higher tensile strength and Vickers hardness values than that of the ZA27 alloy. These improvements in mechanical properties were probably caused by the formation of a eutectoid structure consisting of β-Sn.

Keywords: tin-based alloy, zinc-aluminium alloy, alloying element, mechanical property, microstructure.

並列關鍵字

Sn-based alloys ； ZA27 ； mechanical properties ； microstructures.

參考文獻

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