發(fā)布時(shí)間：2018-04-24 04:24

  本文選題：鈮基高溫合金 + 組織��； 參考：《稀有金屬材料與工程》2017年08期

【摘要】：研究了熱處理對(duì)一種HRS定向凝固技術(shù)制備Nb/Nb5Si3原位復(fù)合材料組織和性能的影響。采用掃描電子顯微鏡(SEM)、X射線衍射(XRD)和電子探針(EPMA)等分析手段對(duì)熱處理過(guò)程中組織演變進(jìn)行了分析:鑄態(tài)合金主要由Nbss、γ-(Nb,Ti)_5Si_3、β-(Nb,Ti)_5Si_3以及初生碳化物組成;熱處理后,鑄態(tài)組織中部分β-(Nb,Ti)_5Si_3向α-(Nb,Ti)_5Si_3轉(zhuǎn)變以及二次碳化物析出,同時(shí)硅化物相逐漸溶解或破碎成小塊并發(fā)生球化;1150℃時(shí)效可促進(jìn)(Nb,Ti)_5Si_3向(Ti,Nb)5Si3轉(zhuǎn)變。熱處理后,合金壓縮以及室溫拉伸強(qiáng)度提高,而1000℃拉伸強(qiáng)度變化不明顯;溫度對(duì)斷裂方式有明顯影響,低溫下為脆性解理斷裂,高溫下為韌性斷裂。
[Abstract]:The effect of heat treatment on the microstructure and properties of Nb/Nb5Si3 in-situ composites prepared by HRS directional solidification technique was studied. The microstructure evolution during heat treatment was analyzed by means of scanning electron microscope (SEM) and electron probe EPMA (EPMA). The as-cast alloy was mainly composed of Nbss, 緯 -NbTiTiSi5Si5Si3, 尾 -NbTiTiSi5SiSn3 and primary carbides. In the as-cast structure, some of the 尾 -NbTi5SiS3 transition to 偽 -nbTiTiTiS3 and secondary carbides precipitation, while the silicide phase gradually dissolves or breaks into small blocks and spheroidized at 1150 鈩，

本文編號(hào)：1795139