(中南大學(xué) 粉末冶金國家重點(diǎn)實(shí)驗(yàn)室，長沙 410083)
摘 要: 采用X射線衍射(XRD)、掃描電鏡(SEM)和能譜分析、差示掃描量熱法(DSC)分析、金相觀察和顯微硬度測(cè)定，研究鐵基合金Fe-14Cr-3W-5Ti-3Y-2.2O(質(zhì)量分?jǐn)?shù)，%)中氧化物彌散相的形成和演化過程，以及氧化物彌散相對(duì)鐵基合金的強(qiáng)化作用。結(jié)果表明：在高能球磨過程中，TiH2、YH2和Fe2O3可以在霧化粉末Fe-14Cr-3W基體中充分固溶；在隨后的壓制、燒結(jié)過程中，當(dāng)燒結(jié)溫度為950 ℃時(shí)彌散相以Ti2Y2O7相的形式析出，其強(qiáng)化作用不明顯，合金的顯微硬度只有250HV；當(dāng)燒結(jié)溫度為1 100 ℃時(shí)，燒結(jié)體致密度得到提高，彌散相強(qiáng)化效果顯著，合金的顯微硬度為798HV；隨著燒結(jié)溫度的提高，析出相粒子長大，合金的顯微硬度降低。
關(guān)鍵字: 鐵基高溫合金；氧化物析出相；彌散強(qiáng)化；TiH2；YH2；Fe2O3；TiY2O7
oxide strengthening phase in iron-based superalloy
（State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China）
Abstract:The formation, evolution and the enhancing effects of the oxide strengthening phase on the iron-based alloy Fe-14Cr-3W-5Ti-3Y-2.2O (mass fraction, %) were studied by X-ray diffractometry, scanning electron microscopy, energy spectrum analysis, DSC analysis, optical microscopy and microhardness test. The results show that, during the mechanical alloying process, TiH2, YH2 and Fe2O3 can dissolve in the atomized powder Fe-14Cr-3W. The Ti2Y2O7 phase will precipitate at 950 ℃ during the following pressing and sintering processes, the enhancing effects are not obvious and the microhardness is about 250HV. When sintered at 1 100 ℃, the compactness of the sintered alloy increases, the enhancing effects of the oxide strength phase are improved, and the microhardness increases to 798 HV by the dispersion phase. The precipitation phase grows and the microhardness decreases with increasing sintering temperature.
Key words: iron-based superalloy; oxide precipitation phase; dispersion strengthening; TiH2; YH2; Fe2O3; TiY2O7
