臺灣博碩士論文加值系統

本實驗應用惰氣鎢極電弧焊,對A356鋁合金的擠壓鑄件和重力鑄件,以
不同的惰氣流量,焊接填料及熱處理製程,分類調查其對於焊接品質的影響
。並將焊件施與陽級處理後分類討論之。 研究發現,惰氣流量對焊道
中殘留的氣孔數量及低熔點合金的汽化揮發有很大的關係。焊道的性質亦
根據填料的成份及金相微結構組織的不同而有差異。 實驗結果指
出:1.當惰氣流量增加時(超過20L/min.),可以減少焊道中殘留氣孔的數
量,並抑制焊道中低熔點合金成份的汽化揮發。2.T6熱處理後再焊接的熱
影響區擴大,其硬度值,陽極處理表面及晶粒大小均有不同。3.Si含量越
高,則焊件經陽極處理後,其外觀灰暗的程度越高。

A356 aluminum alloy of the squeeze castings and gravity
castings were fusion welded with the gas tungsten arc welding
process.The effects of gas flow rates,T6 heat treatment, and the
type of filler metal were investigated under different welding
conditions. The appearance of the welded surface under anodic
treatment was also compared and analyzed. It was found that the
gas flow rates greatly influenced the weld porosity and the
evaporation of low boiling point alloy element (such as Mg).The
resulting properties of the welding are caused by both the
filler metal composition and the microstructure in the fusion
zone and heat-affected zone. The result of these experiments
indicated that:1.Increasing shielding gas flow rates,above 20L/
min.,was reduced weld porosity and inhibited the evaporation of
magnesium.2.The extent of heat-affected zone was widened in
welding under T6 heat treatment. It also concerned about
hardness profile,anodic coating and grain size.3.The more
content of silicon in aluminum alloy castings resulted a gray
colorof appearance which under anodic treatment.