鍛造溫度對鈦-6鋁-4釩合金顯微組織之影響

Effects of the Forged Temperatures on the Microstructure of the Ti-6Al-4V Alloy

葉松翰(Song-Han Ye)

指導教授 ： 趙志燁

國立屏東科技大學/工學院/機械工程系所/碩士(2010年)

https://doi.org/10.6346/NPUST.2010.00236

摘要

本研究目的是分析鈦-6鋁-4釩和金，經不同鍛造加熱溫度(800~1000℃)做閉模鍛造塑性變形，經由掃描式電子顯微鏡、穿透式電子顯微鏡儀器觀察顯微結構之變化。另外探討高爾夫球頭打擊面板CT值與耐久測試之差異。
合金於Ms轉換溫度以下壓縮區顯微結構為初析α+β，膨脹區結構為初析α+α"+β，鍛造織構方位為[0001]；Ms轉換溫度以上主要結構為析出α+層狀α'+β，鍛造織構方位為[2110]、[0111 ]；α/(α+β)轉換溫度以上鍛造，主要結構為層狀麻田散鐵α'，鍛造織構方位為[2110]。比較鍛造後與未鍛造試片，可得Ms轉換溫度提升30-40℃。經計算可得α相晶格常數a=0.292~0.294 nm、c=0.466~0.468 nm、c/a比值為1.596~1.602；β相晶格常數a=0.330 nm；α'相晶格常數a=0.290~0.292 nm、c=0.460~0.465 nm、c/a比值為1.586~1.592；α"相晶格常數為a=0.298 nm、b=0.494 nm、c=0.464 nm。
高爾夫球頭在雙相結構區特性，具有高砲擊強度及低CT值；當高爾夫球頭有高比例之α'結構，具有高CT值和低砲擊強度。

關鍵字

鈦合金 ； CT值 ； α" ； 鍛造

並列摘要

The main purposes of the present studies are to analyze the Ti-6Al-4V alloy close-die forged during the various heated temperature in the range between 800℃ and 1000℃ by use of the SEM and TEM technology. The contact time (CT) and golf-ball impact strength are also investigated.
Below the Ms transition temperature, the microstructures of the compression region and tension region are the primary α + β mixture phases and primary α + α" + β mixture phases. The texture of the forge is [0001]. Above the Ms transition temperature, the microstructure of the compression region and tension region is a primary α + lamellar α' + β mixture phases. The texture of the forge is [2110] and [0111]. When forged above α/(α+β) temperature, the microstructure of the alloy is a single lamellar α' phase. The texture of the forge is [2110]. Compared the forged and un-forged specimen, it is found that the Ms transition temperature of the forge will increase about 30-40℃. The lattice parameter of α and α' structure is a=0.292-0.294 nm, c=0.466-468 nm, c/a=1.596-1.602, and a=0.290-0.292 nm, c=0.460- 465 nm, c/a=1.586-1.592, respectively. The lattice parameter of the β and α" structure is a=0.330 nm, and a=0.298 nm, b=0.494 nm and c=0.464 nm, respectively.
It is found that the properties of the golf head made by the present specimens with α + β bimodal structure can possess the lower CT value and higher ball-impact strength. When the golf head with the higher α' structure ratio, the CT value of the golf head will increase and ball-impact strength decrease.

並列關鍵字

Titanium alloy ； CT value ； α" ； forge

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