Spatial phase structure and oxidation process of Al-W alloy powder with high sphericity

doi:10.1016/j.jmst.2021.10.004

Abstract

Abstract:

In this study, Al-30W (wt.%) alloy powder was prepared by Aluminothermic reduction and high-temperature gas atomization. We then studied the phase composition, surface morphology, spatial phase structure, and thermal oxidation process using XRD, SEM/EDS, TEM, DSC, and DTA/TG analysis. The results showed that the Al-30W alloy powder exhibited high sphericity, and the interior presented a special spatial phase structure in which the Al/W amorphous alloy phase and the metastable Al/W intermetallic compound phase were distributed in the pure Al matrix. When the Al-30W alloy powder was stabilized in a vacuum tube furnace, the spatial phase structure of the alloy powder changed, and a small amount of pure Al was embedded in the Al₁₂W matrix. The resulting Al-30W alloy powder products, treated in air at different temperatures, were collected in situ and characterized. The results presented that with an increase in temperature, the types and morphologies of the Al/W intermetallic compounds in the Al-30W alloy powder changed. Furthermore, the Al-30W alloy powder began to undergo intense oxidation reactions at about 900 °C, accompanied by a concentrated energy release and rapid weight gain. The volatilization of WO₃ produced in the oxidation process promoted the complete oxidation of the Al-30W alloy powder, and the Al-30W alloy powder was completely oxidized at 1300 °C. At this stage, all W atoms were transformed into gaseous WO₃, and only a large number of small Al₂O₃ fragments remained in the oxidation product. Thus, the Al-30W alloy powder exhibited excellent thermal reactivity and oxidation integrity, and may offer excellent application prospects in the field of energetic materials.

Key words: Aluminothermic reduction, High-temperature gas atomization, Al/W amorphous alloy phase, Metastable Al/W intermetallic compound phase, Thermal oxidation process

Aobo Hu, Shuizhou Cai. Spatial phase structure and oxidation process of Al-W alloy powder with high sphericity[J]. J. Mater. Sci. Technol., 2022, 114: 62-72.

Figures/Tables 21

Fig. 1. SEM photographs of the Al-30W alloy powder prepared by high-temperature gas atomization ((b) is the magnification of the area selected in (a)).

Fig. 2. XRD pattern of the Al-30W alloy powder.

Table 1. Atomic ratios of the elements contained in the Al-30W alloy powder.

Al	W	Mo	Cu	Y	Co	Fe
94.0581	5.7615	0.0840	0.0321	0.0229	0.0227	0.0187

Fig. 3. SEM photograph and EDS spectra of single particle cross section of the Al-30W alloy powder (backscattered electron image).

Fig. 4. TEM low-magnification morphology and SEAD/HRTEM images of the Al-30W alloy powder.

Fig. 5. SEM photographs of the Al-30W* alloy powder ((b) is the magnification of the area selected in (a)).

Fig. 6. XRD pattern of the Al-30W* alloy powder.

Fig. 7. SEM photograph and EDS spectra of single particle cross section of the Al-30W* alloy powder (backscattered electron image).

Fig. 8. TEM low-magnification morphology and SEAD/HRTEM images of the Al-30W* alloy powder.

Fig. 9. EDS surface scan images of the area selected in Fig. 7.

Fig. 10. DSC curves for the Al-30W and Al-30W* alloy powders in pure argon.

Fig. 11. DTA/TG curves of the Al-30W alloy powder in air.

Fig. 12. XRD patterns of the heat-treated products of the Al-30W alloy powder at different temperatures in air.

Fig. 13. SEM photographs and EDS spectra of single particle cross section of the Al-30W alloy powder (backscattered electron image, (a) is the intermediate state from Al12W to Al5W, (b) is the 750 °C heat-treated product).

Table 2. EDS point scanning results for the phases located at four different positions in Fig. 13.

Position number	1	2	3	4
Atomic ratio (Al : W)	92.52 : 7.48	83.09 : 16.91	99.81 : 0.19	82.36 : 17.65

Fig. 14. SEM photographs and EDS spectra of single particle cross section of the Al-30W alloy powder (backscattered electron image, (a) is the intermediate state from Al5W to Al4W, (b) is the 900 °C heat-treated product).

Table 3. EDS point scanning results for the phases located at four different positions in Fig. 14.

Position number	1	2	3	4
Atomic ratio (Al : W)	79.61 : 20.39	83.52 : 16.48	99.56 : 0.44	80.18 : 19.82

Fig. 15. XRD patterns of the oxidation products of the Al-30W alloy powder at different temperatures in air.

Fig. 16. In-situ SEM photographs of the oxidation product of the Al-30W alloy powder at 1100 °C ((b) is the magnification of the area selected in (a)).

Fig. 17. EDS surface scan images of the area selected in Fig. 16(b).

Fig. 18. In-situ SEM photographs of the oxidation product of the Al-30W alloy powder at 1300 °C ((b) is the magnification of the area selected in (a)).

References 54

[1]	B. Palaszewski, R. Powell, J. Propul. Power 10 (1994) 828-833. DOI URL
[2]	D. Hu, Z.M. Sun, Combust. Flame 105 (1996) 428-430. DOI URL
[3]	A. Ingenito, C. Bruno, J. Propul. Power 20 (2004) 1056-1063. DOI URL
[4]	A.M. Ismail, B. Osborne, C.S. Welch, J. Br. Interplanet. Soc. 65 (2012) 61-70.
[5]	F. Maggi, S. Dossi, C. Paravan, L.T. DeLuca, M. Liljedahl, Powder Technol 270 (2015) 46-52. DOI URL
[6]	C. Fang, S.F. Li, Propellants Explos. Pyrotech. 27 (2002) 34-38. DOI URL
[7]	B.C. Terry, T.R. Sippel, M.A. Pfeil, I.E. Gunduz, S.F. Son, J. Hazard. Mater. 317 (2016) 259-266. DOI URL
[8]	H. Zou, L.F. Li, S.Z. Cai, J. Propul. Power 32 (2015) 32-37. DOI URL
[9]	Y.L. Shoshin, E.L. Dreizin, Combust. Flame 145 (2006) 714-722. DOI URL
[10]	A.B. Hu, H. Zou, W. Shi, A.-m. Pang, S.Z. Cai, Propellants Explos. Pyrotech. 44 (2019) 1454-1465. DOI URL
[11]	A. Ilyin, A. Gromov, V. An, O.F. Faubert, C. de Izarra, A. Espagnacq, L. Brunet, Propellants Explos. Pyrotech. 27 (2002) 361-364. DOI URL
[12]	S. Hasani, M. Panjepour, M. Shamanian, Oxid. Met. 78 (2012) 179-195. DOI URL
[13]	M.A. Trunov, M. Schoenitz, E.L. Dreizin, Combust. Theory Modell. 10 (2006) 603-623. DOI URL
[14]	A.P. Il’In, A.A. Gromov, G.V. Yablunovskii, Yablunovskii, Combust. Explos. Shock Waves 37 (2001) 418-422. DOI URL
[15]	V.A. Babuk, V.A. Vassiliev, V.V. Sviridov, Combust. Sci. Technol. 163 (2001) 261-289. DOI URL
[16]	Y.C. Feng, Z.X. Xia, L.Y. Huang, X.T. Yan, Acta Astronaut 129 (2016) 1-7. DOI URL
[17]	J.T. Moore, S.R. Turns, R.A. Yetter, Combust. Sci. Technol. 177 (2006) 627-669. DOI URL
[18]	M. Schoenitz, E.L. Dreizin, J. Mater. Res. 18 (2003) 1827-1836. DOI URL
[19]	Y. Aly, M. Schoenitz, E.L. Dreizin, Combust. Flame 160 (2013) 835-842. DOI URL
[20]	Y. Aly, E.L. Dreizin, Combust. Flame 162 (2015) 1440-1447. DOI URL
[21]	K.T. Lu, C.C. Yang, Propellants, Explos., Pyrotech 33 (2008) 403-410. DOI URL
[22]	E. Shachar, A. Gany, Propellants Explos. Pyrotech. 22 (1997) 207-211. DOI URL
[23]	P.G. Luo, Z.C. Wang, C.L. Jiang, L. Mao, Q. Li, Mater. Des. 84 (2015) 72-78. DOI URL
[24]	X.F. Zhang, A.S. Shi, L. Qiao, J. Zhang, Y.G. Zhang, Z.W. Guan, J. Appl. Phys. 113 (2013) 083508.
[25]	X.B. Zhang, J.X. Liu, L. Wang, S.K. Li, S. Zhang, J. Lan, Y.J. Wang, Rare Met. Mater. Eng. 47 (2018) 1723-1728. DOI URL
[26]	C. Ge, W. Maimaitituersun, Y.X. Dong, C. Tian, Materials (Basel) 10 (2017) 452. DOI URL
[27]	M.I. Alymov, S.G. Vadchenko, I.V. Saikov, I.D. Kovalev, Inorg. Mater.: Appl. Res. 8 (2017) 340-343. DOI URL
[28]	L. Wang, J.X. Liu, S.K. Li, X.B. Zhang, AIP Adv 5 (2015) 117142.
[29]	L. Wang, J.X. Liu, S.K. Li, X.B. Zhang, Mater. Des. 92 (2016) 397-404. DOI URL
[30]	N. Radić, T. Car, A. Tonejc, J. Ivkov, M. Stubičar, M. Metikoš-Huković, Phys. Technol. Thin Films (2004) 101-108.
[31]	H. Habazaki, P. Skeldon, G.E. Thompson, G.C. Wood, K. Shimizu, Philos. Mag. B 71 (1995) 81-90. DOI URL
[32]	T. Car, N. Radi, J. Ivkov, E. Babić, A. Tonejc, Appl. Phys. A 68 (1999) 69-73. DOI URL
[33]	J. Ivkov, N. Radi´c, A. Tonejc, T. Car, J. Non-Cryst. Solids 319 (2003) 232-240. DOI URL
[34]	T. Car, N. Radic, J. Ivkov, A. Tonejc, Appl. Phys. A 80 (2005) 1087-1092. DOI URL
[35]	M. Stubičar, A. Tonejc, N. Radi, Vacuum 61 (2001) 309-316. DOI URL
[36]	H. Yoshioka, H. Habazaki, A. Kawashima, K. Asami, K. Hashimoto, Corros. Sci. 32 (1991) 313-325. DOI URL
[37]	A. Tonejc, J. Mater. Sci. 7 (1972) 1292-1298. DOI URL
[38]	C. Suryanarayana, J. Mater. Sci. 8 (1973) 760-761. DOI URL
[39]	N.I. Varich, R.B. Lyukevich, Izv. Akad. Nauk SSSR Met. 2 (1970) 216-219.
[40]	L.G. Raskolenko, A.Y. Gerul’skii, Inorg. Mater. 44 (2008) 30-39. DOI URL
[41]	M. Tsukada, S. Ohfuji, J. Vac. Sci. Technol. A 13 (1995) 2525-2531. DOI URL
[42]	C. Wang, S.H. Liang, Y.H. Jiang, Vacuum 160 (2019) 95-101. DOI URL
[43]	G. Dercz, J. Piątkowski, Solid State Phenom 163 (2010) 161-164. DOI URL
[44]	C.L. Zhang, P. Lv, J. Cai, Y.W. Zhang, H. Xia, Q.F. Guan, J. Alloys Compd. 723 (2017) 258-265. DOI URL
[45]	C.J. Zhu, X.F. Ma, W. Zhao, H.G. Tang, J.M. Yan, S.G. Cai, J. Alloys Compd. 393 (2005) 248-251. DOI URL
[46]	S. Varam, P.V.S.L. Narayana, M.D. Prasad, D. Chakravarty, K.V. Rajulapati, K.B.S. Rao, Philos. Mag. Lett. 94 (2014) 582-591. DOI URL
[47]	H.Z. Zhang, P.Z. Feng, F. Akhtar, Sci. Rep. 7 (2017) 12391.
[48]	L.F. Li, H. Zou, S.Z. Cai, Mater. Sci. Technol. 32 (2016) 863-870. DOI URL
[49]	H. Fu, H. Zou, S.Z. Cai, Adv. Powder Technol. 27 (2016) 1898-1904. DOI URL
[50]	Q. Luo, Y. Guo, B. Liu, Y. Feng, J. Zhang, Q. Li, K. Chou, J. Mater. Sci. Technol. 44 (2020) 171-190. DOI URL
[51]	Y. Pang, D. Sun, Q. Gu, K. Chou, X. Wang, Q. Li, Cryst. Growth Des. 16 (2016) 2404-2415. DOI URL
[52]	Y. Guo, B. Liu, W. Xie, Q. Luo, Q. Li, Scr. Mater. 193 (2021) 127-131. DOI URL
[53]	T. Xie, H. Shi, H. Wang, Q. Luo, Q. Li, K. Chou, J. Mater. Sci. Technol. 97 (2022) 147-155. DOI URL
[54]	Q. Li, X. Lin, Y.Chen Q.Luo, J. Wang, B. Jiang, F. Pan, Int. J. Miner. Metall. Mater. 29 (2022) 32-48. DOI URL