Development of New Surface Treatment Using Shot Blast for Improving Oxidation Resistance

Transcription

1 Developent of Ne Surface Treatent Uing Shot Blat for Iproving Oxidation Reitance Hiroyuki Kaaura, Hirohi Kaahara, Kazuaki Nihino, Takahi Saito C A ne urface treatent uing hot blat ith WO 3 poder ha been developed. Thi ha been very effective for iproving the cyclic oxidation reitance of TiAl-bae alloy in air and in an exhaut ga atophere of a dieel engine up to 1223K. Thi effect i due to the foration of an Al 2 O 3 layer in the oxidation atophere. The above layer i uppoed to be fored a follo: Since the WO 3 poder i repeatedly hot during the urface treatent, a WO 3 layer adhering to the ubtrate i fored on the urface. Thi layer caue the preferential oxidation of aluinu during the early tage of oxidation, reulting in the foration of a ound and continuou Al 2 O 3 layer. The developed urface treatent provide the ae oxidation reitance a that of the nickel-bae uperalloy Inconel 713C up to 1223K, and i applicable for coplexhape part ith a-cat kin urface, uch a turbocharger heel. Furtherore, the developed urface treatent i extreely effective for it application to other alloy uch a titaniu alloy and tainle teel.

2 Mo Nb Si W P Cl TiAl TiAl WO 3 TiAl Al Al 2 O TiAl (1) (2) (3) (4) TiAl [ ( SB ) ] WO 3 SB TiAl SB TiAl SB Ti Inconel 713C ( µ µ 99.9 )WO 3 ( 5 20µ 99.9 ) MPa 5010ec/c K 1223K 2 Cheical copoition of Ti-47Al pecien. Al Ti O Si Ca (ol%) (a%) 47.4 Balance Cheical copoition of Inconel 713C pecien. (a%) Cr Mo Al Nb Ti Zr C B Copreed air ( MPa) Ti-47Al Ni Balance Ti-47Al (ol%) Spray gun Treating poder (W,WO3) Scheatic draing of urface treatent uing hot-blat equipent.

3 1.8k 2 90k180k 1223K 18k X SEM (AES) W WO 3 SB Ti-47Al1173K SB WO 3 720k 2g/ K 1 Cycle (3.6k) 1223K WO 3 SB 1223K 360k 0.4MPa 0.4MPa SB WO 3 -SB Ti-47Al WO 3 -SB 1223K Inconel 713C WO 3 -SB Inconel 713C 1223K 90k Ma gain, W / 10-3 kg Ti-47Al 1173K in air 90 k or 180 k cycle W WO Oxidation tie, t / 3.6 k Heating (1.8k) Ma gain due to cyclic oxidation of Ti-47Al pecien by SB treatent ith W or WO 3 poder. 373K Teperature veru tie curve of hort-ter oxidation tet. Copoition of odel exhaut ga for oxidation tet. O 2 CO 2 NO CO C 3 H 6 SO 2 H 2 O N vol.% 7.4 vol.% 0 pp 760 pp 600 pp 300 pp 3.5 vol.% Balance Ma gain, W / 10-3 kg Ti-47Al 1223 K-360 k in air 90 k or 180 k cycle WO 3 -SB treated Pneuatic preure, MPa 0.8 Relation beteen pneuatic preure in hot blat and a gain of the WO 3 -SB treated pecien oxidized at 1223K for 360k in air.

4 WO 3 -SB 1800k WO 3 SB Ti-47Al 1223K Inconel 713C Ti-47Al WO 3 -SB 1223K SEM 7.2k 180k 720k SB WO 3 ( Fig. 7(a) ) ( Fig. 7(b) ( Fig. 7(c) ) 0.5 1µ ( Fig. 7(d) ) 180k ( Fig. 7(e) ) 5µ µ ) 720k ( Fig. 7(g) (h) ) 1µ ( Fig. 7(h) ) Ti-47Al WO 3 -SB 1223KX SB TiAl Ti 3 AlWO 3 0 WO 3 Ti-47Al, 1223 K in air 720k 1.8k 1.8 k cycle 2Al 2 O 3 5WO 3 Al 2 O 3 TiO 2 2Al 2 O 3 5WO 3 36k 36k Al 2 O 3 TiO 2 10 WO 3 -SB treated Inconel 713C SBAES W O Oxidation tie, t / 3.6 k Ma gain due to cyclic oxidation of Ti-47Al pecien by WO 3 -SB treatent at 1223K. 720k W (1) O Al Ti (2) O AlTi (3) Ti Al O SEM X AES (1) WO 3 -SB TiAl WO 3 (2) WO 3 TiAl Al WO 3 TiAl 2Al 2 O 3 5WO 3 Al 2 O 3 (3) WO 3 Al 2 O 3 (a) ( after 180 k ) (b) WO 3 -SB treated ( after 1800 k ) Al 2 O 3 Appearance of (a) and WO 3 -SB treated (b) Ti-47Al pecien oxidized at 1223K in air after the hort-ter cyclic WO 3 -SB oxidation tet. Ma gain, W / 10-3 kg -2

5 SEM of the outer urface and the fractured ection of Ti-47Al pecien by WO 3 -SB treatent, before oxidation (a and b), after oxidation at 1223K for 7.2k (c and d), after oxidation at 1223K for 180k (e and f), and after oxidation at 1223K for 720k (g and h).

6 Ma gain, W / 10-3 kg -2 Ti-47Al WO 3 -SB 1223KInconel 713C SB Inconel 713C SB (1) (2) Ti-47Al ( ) WO 3 -SB 1223K 180k WO 3 -SB Suary of XRD data for WO 3 -SB treated Ti-47Al pecien oxidized at 1223K. Oxidation tie After SB treatent 1223K-1.8k 1223K-3.6k 1223K-7.2k 1223K-36k 1223K-180k 1223K-720k Intenity of detected peak TiAl Ti 3 Al WO 3 2Al 2 O 3 5WO 3 Al 2 O 3 TiO 2 AES depth profile near the urface of the WO 3 - SB treated Ti-47Al pecien after oxidation at 1223K for 720k Ti-47Al, 1223K in exhaut ga Inconel 713C WO 3 -SB treated Oxidation tie, t / 3.6k =trong, =ediu, =eak, =nothing Ma gain due to cyclic oxidation in exhaut ga of Ti-47Al pecien WO 3 -SB treated at 1173K. (a) ( after 180k ) (b) WO 3 -SB treated ( after 720k ) AES depth profile near the urface of the WO 3 -SB treated Ti-47Al pecien. Appearance of (a) and WO 3 -SB treated (b) Ti-47Al turbine heel oxidized at 1223K in exhaut ga atophere.

7 720k WO 3 -SB SB MoSi 2, NbSi 2 WSi 2 SBTi ( Tietal 1 ) 1073K SB MoSi 2 720k 15g/ K MoSi 2, CrSi 2 ZrSi 2 SB SUS K CrSi 2 ZrSi 2 SB SUS310S Ti (1) WWO 3 Ti-47Al WO 3 WO 3 -SB 1223K Inconel 713C (2) WO 3 -SB WO 3 WO 3 TiAl WO 3 TiAl Al Ma gain, W / 10-3 kg SUS304,1223K in air k k or or 180 k cycle SUS310S CrSi 2 ZrSi 2 MoSi Oxidation tie, t / 3.6 k Ma gain due to cyclic oxidation of SUS304 pecien by SB treatent ith ZrSi 2, CrSi 2 or MoSi 2 poder. TiAl Ma gain, W / 10-3 kg Tietal K-720k in air 90k or 180k cycle WSi 2 NbSi 2 MoSi 2 5 SB treated (a) ( after 180k ) (b) ZrSi 2 -SB treated ( after 720k ) Ma gain due to cyclic oxidation of Ti alloy by SB treatent ith WSi 2, NbSi 2 or MoSi 2 poder. Appearance of (a) and ZrSi 2 -SB treated (b) SUS304 pecien after the cyclic oxidation tet at 1223K.

8 2Al 2 O 3 5WO 3 Al 2 O 3 Al 2 O 3 (3) WO 3 -SB (4 SB Ti 1) Nihiyaa, Y., Miyahita, T., Iobe, S. and Noda, T. : "Developent of Titaniu Aluinide Turbocharger Rotor", High Teperature Aluinide and Interetallic, Ed. by Whang, S. H., Liu, C. T., Pope, D. P., and Stiegler, J. O., (1990), 557, The Mineral, Metal & Material Society 2) Doling, W. E. Jr., Allion, J. E., Sank, L. R., Sheran, A. M. : "TiAl-Baed Alloy for Exhaut Valve Application", SAE Tech. Pap. Ser., No , (1993) 3) Maki, K., Ehira, A., Sayahi, M., Saaki, T., Noda, T., Okabe, M. and Iobe, S. : "Developent of a High-Perforance TiAl Exhaut Valve", SAE Tech. Pap. Ser., No , (1996) 4) Taniguchi, S. and Shibata, T. : "Influence of Additional Eleent on the Oxidation Behaviour of TiAl", Interetallic, (1996), S85 5) : 1023K 1073K TiAl",, -12(1997), ) TiAl,, (1991), 274 7) : WO 3 TiAl, 101 (1994), 28 8) Brady, M. P., Brindley, W. J., Sialek, J. L. and Locci, I. E. : The Oxidation and Protection of Gaa Titaniu Aluinide, JOM, -12(1996), 46