金属間化合物における粒内変形支配の超塑性的挙動に関する研究 26 AF-21427 キーワード 1. 緒言 1 1) 2) Class I 3) 3) Class I Cottrell Jaswon 4) 5) Solute drag 5 solute drag 3 3 6) 1 Ti 3 Al Ti 3 Al 2. 方法 2.1 供試材 Ti 3 Al 1 3 µm 2.2 放電プラズマ焼結 1 Ti 3 Al Elements wt % at % Al Ti 18.3 bal. 28.4 bal. Spark Plasma Sintering: SPS 2 mm 4 mm T = 188123 1323 K s = 163248 MPa t = 1 min 2.3 相対密度 7) Ti 3 Al Ti 3 Al = 3.9 g/cm 3 Ti 3 Al =2.45 g/cm 3 8) 2.4 組織観察 Scanning Electron Microscopy: SEM Field Emission Type Scanning Electron Microscopy: FE-SEM Electron Backscattering Diffraction: EBSD Ti 3 Al SEM Ti 3 Al FE-SEM EBSD #8 #43 µm : 7 : min: 1 rpm EBSD T = 188 K 2 kv µm μm 1 μm T = 123 K 2 kv µm μm 1.5 μm 2 kv 2 µm 2 μm 4 μm
2.5 ビッカース硬さ ##1# #43 µm 19.64 N 15 sec 5 mm 5 2.6 高温圧縮試験 Ti 3 Al s = 48 MPa 3 3 3 mm 3 T = 1173, 1223, 1273 K!ε = 1 1 4 3 1 4 1 1 3 s 1 15 min.15 3. 結果および考察 3.1 相対密度 1 Ti 3 Al r th r app % 657% Relative Density, r* (%) 9 8 7 r th = 3.9 g/cm 3 r app = 2.45 g/cm 3 Open Symbol : r th Solid Symbol : r app T = 123 K T = 188 K Ti 3 Al Intermetallic Compound 1 2 3 4 Sintering Stress, s / MPa 1 Ti 3 Al 3.2 空孔面積率 2 T = 188 K 81% T = 123 1323 K 2%3.1 % 657% 3 µm 3.3 室温力学特性 3 1 Hall-Petch 9, 1) H V = H + k (1) d H V H k d 4 Void Area Fraction, F v (%) 2 18 16 14 12 1 8 6 4 2 Ti 3 Al Intermetallic Compound T = 188 K T = 123 K 1 2 3 4 Sintering Stress, s / MPa 2 Ti 3 Al
3.4 高温圧縮試験に用いた焼結体の初期ミクロ組織 Í 6 )ȂťÑƩLJȁ)Ź Ti3Al Intermetallic Compound 4 4 s = 48 MPa % :Ȉ *ūƣ *üóƣĺɲćȅdȇ+ȇ 3 465 ± 12 µm *1Ɩǘ(ƞÝƢƪ 8őĖ ;$ "$ȇłƅƒ)ź 3 2 2 1 T = 123 K T = 188 K 1 2 3 4 Sintering Stress, s / MPa Í 3 Ti3Al ūƣ *éť) :_UEtNƆ &ūƣđ *DZ Vickers Hardness, HV / MPa : ȇɯŀć79+č ơ&ƭ 8;:ȈȆ*ƞÝ(Ɯŀ=Ź ƣĺɲėǭ Ÿ $ Ti3Al Intermetallic Compound 4 4 3 3 2 2 1 T = 123 K T = 188 K.5.1.15.2.25 Grain Size, d.5/ µm.5 ȇsps )79 :5*&ƭ 8;:Ȉ "$ȇ 4 Ti3Al Intermetallic Compound 4 3 3 T = 123 K 2 2 T = 188 K 1 65 7 75 Relative Density, r* (%) Í 5 Ti3Al ūƣ *_UEtNƆ &Ƃïëþ*DZ Í 4 Ti3Al ūƣ *_UEtNƆ &ƣĺɲć*dz nsbut*dz 8Łń+Áv 9*ƁƧ%Ɖ ;:+ % : ȇłƅƒ* Ti3Al ūƣ %+ǝctnsbut *DZ ĖƔ $ :Ȉ ;=ƭí : 4)ȇÍ 5 )_ UEtNƆ &Ƃïëþ*DZ =Ɖ Ȉ *Í 8 : 7 )ȇłɛ* Ti3Al ǫôǰ²ãůūƣ *_UEtNƆ +ȇƃïëþ Ý 'Ɔ Åv $ :Ȉ ;+ȇ _UEtNƆ =Ŧç :Ƕ)ȇLJIJƸǺ=ƅƈ ȇ 3.2 ƚ%ǜ/ 7 )ȇłƅƒ%*ɠâąė+ūƣ ÛƸ Ǻ)Ü ãò & Ē ;ȇ *ƓâŕǴ=ƅƈ% +æ )dz¹% ( " 4ȇ_UEtNƆ ƣĺɲ 3 µm Ć) ã :795ƓâǺƑŴ) ã $ 2" ÀƯ đ 9ȇ ĉȇ ŎDŽ :ďƻ :Ȉ ƜŀĆ+ 3 µm wȅ ȇɯŀ *ƣĺɲć+ŀǃŧ% Ti3Al ūƣ * ľfhp Ƣƪ=Ɖ ȈūƣŃ +ȇūƣťþ ȇūƣđ Vickers Hardness, HV / MPa Vickers Hardness, HV / MPa :Ȉ Í6 ȂťÑƩLJȁ)Ź Ti3Al ūƣ * ľƣƪ
1 µm 3.5 高温圧縮試験 7 Ti 3 Al Ti 3 Al True Stress, s / MPa True Stress, s / MPa True Stress, s / MPa 4 4 3 3 2 2 1 4 4 3 3 2 2 T = 1273 K e = 1 1 4 s 1 e = 3 1 4 s 1 e = 1 1 3 s 1.2.4.6.8.1.12.14.16 True Strain, e T = 1223 K e = 1 1 3 s 1 1 e = 3 1 4 s 1 e = 1 1 4 s 1 (b).2.4.6.8.1.12.14.16 True Strain, e 4 4 3 3 2 2 1 T = 1173 K e = 3 1 4 s 1 e = 1 1 4 s 1 e = 1 1 3 s 1 (c).2.4.6.8.1.12.14.16 True Strain, e 7 Ti 3 Al (a) 3.6 高温変形機構 2 Dorn 11)!ε = Aσ n exp Q (2) RT!ε A sn n Q R T 2 nq Ti 3 Al n 8 Ti 3 Al n 6 n n = 4 7 Ti 3 Al 23 ( ) ( ) Q = nr lnσ (3) 1 T 9 Ti 3 Al 6 3 1 4 s 1 3 Ti 3 Al 333 kj/mol Ti 3 Al Initial Strain Rate, e / s 1 1 2 1 3 1 4 1 5 7 7 Flow stress, s / MPa 8 Ti 3 Al n 1 6
Flow stress, ln s / MPa 19.8 19.6 19.4 19.2 19. e = 3 1 4 s 1 n = 6 Q app = 333 kj/mol lns (1/T) Q Ti = 288 kj/mol (Reference) 3 Al 18.8.72.76.8.84.88.92 Reciprocal Absolute Temperature, 1 3 T 1 / K 1 9 Ti 3 Al Ti 12) 288 kj/mol Ti 3 Al Ti 3 Al Ti Class I solute drag 3 Wolfenstine Ti 3 Al 6) 123 1173 K 11 7 s 1 3 Wolfenstine 6) solute drag 4. 結言 Ti 3 Al [1] Ti 3 Al % 657% [2] Ti 3 Al T = 188 K 81% T = 123 1323 K 2% [3] Ti 3 Al [4] Ti 3 Al [5] Ti 3 Al 465 ± 12 µm 1 µm [6] Ti 3 Al Ti 3 Al Ti [7] Class I solute drag 3 Wolfenstine Ti 3 Al 123 1173 K 1 1 7 s 1 3 謝辞 26 AF-21427 NIMS 参考文献 1) (24) 2) T. G. Nieh, J. Wadsworth, and O. D. Sherby: Superplasticity in Metals and Ceramics, (1997), Cambridge University Press. 3) 62-9 (212), 344. 4) A. H. Cottrell, and M. A. Jaswon: Phil. Trans. Roy. Soc. A, 199 (1949), 14. 5) J. Weertman: Trans. Metal. Soc. AIME, 218 (19), 27. 6) J. Wolfenstine: J. Mater. Sci. Lett., 9 (199), 191. 7) 3-11 199379.
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