鈷含量對Mar-M247超合金微觀組織影響之研究

Effect of Cobalt Content On The Microstructure of Mar-M247 Superalloy

謝長泉(C. C. Shieh) ； 張忠柄(C. P. Chang) ； 唐江濤(T. T. Jang) ； 徐念南(N. N. Hsu)

《鑛冶：中國鑛冶工程學會會刊》 27卷2期 (1983/06) Pp. 65-79

https://doi.org/10.30069/MM.198306_27(2).0007

摘要

本文利用掃描式與穿透式電子顯微鏡觀察減少了鈷含量的Mar-M247鎳基超合金微觀組織之變化，用掃描式電子顯微鏡觀察γ'析出的形態，發現鈷含量減少後，方形γ'的體積分數隨之遞減，不規則的γ'比例增加，鈷含量降至零時，有聚集成團狀且粗大的碳化物出現，其成份亦與含鈷之合金中的碳化物不同；用穿透式電子顯微鏡觀察其疊差形態，發現沒有太大的差異，疊差所在的平面均為｛111｝，是由一個完整的1/2＜110＞差排分解成兩個1/6＜112＞部份差排所形成。利用差排對（dislocation pairs）分開的距離求得的APB（antiphase boundary）能量顯示鈷含量減少時APB能量將逐漸增大，其增加之幅度約為每減少1％鈷含量APB能量增大0.62 erg/cm^2。用部份差排分開的距離估計疊差能的大小，其結果顯示隨着鈷含量的減少疊差能有逐漸增加的趨勢。鈷含量減少到零時，發現有一種微細且散佈的新析出物，其格子常數為3.40Å，它是何種析出物尚須進一步的研究探討。

並列摘要

The microstructure change of cobalt reduced Mar-M247 superalloys was examined by use of SEM and TEM. The volume fraction of γ' precipitate decreases as the cobalt content in the Mar-M247 superalloy was reduced. Change of γ' morphology was noticed and the amount of irregular γ' precipitates increases as cobalt was extracted from the alloy. Blocky type of carbide agglomerates was observed in the cobalt-free samples. These large blocky type carbides have different composition with the carbides obsered in the other cobalt contained alloys. From TEM study, the stacking fault morphology was observed. There seems no effect by the amount of cobalt content. All stacking faults were found on the {111} type plane formed by dissolution of a perfect dislocation with Burgers vector of 1/2＜110＞ and two dissolved partials of 1/6＜112＞ types. The antiphase boundary (APB) energies of different alloys were calculated out by measuring the distances between dislocation pairs. The values of this energy increase as the cobalt content was decreased. The increment of this value is about 0.62 erg/cm^2 per 1w/o decrease of the cobalt content in the alloy. From the observations of the distances between the dissolved partial dislocations, stacking fault energies (SFE) were also obtained. The results show that SFE increases as the cobalt content was decreased. There are many very fine dispersed particles with a lattice constant of about 3.40Å were observed in the cobalt-free alloy. We don't know what they are and a further study may be needed to identity them.