Y. Fu, Y. Gao, Dalian Maritime University, Dalian, China; Z. Hei, Dalian Maritime University, DaLian, China
The effect of substrate temperature during the low-power plasma spraying (2.5~8.0kW) and after annealing on the phase transformation of Al-Cu-Cr quasicrystalline coatings were investigated. Compared with the original powder mainly composed of icosahedral I-Al
65Cu
24Cr
11 quasicrystalline phase and monoclinic θ-Al
83Cu
4Cr
13, the coatings show an icosahedral quasicrystal
I-Al
65Cu
24Cr
11 and its body-centered cubic approximant α-Al
69Cu
18Cr
13. XRD patterns indicated that for identical spraying condition, the rise of substrate temperature was accompanied by an increase of the I/α peak intensity ratio in the coatings, and the crystalline phases of AlCu
4 and Al
86Cr
14 were observed in the coatings after annealing at 1113K for half an hour.
Key Words: Low-power plasma spray; Al-Cu-Cr quasicrystal; Phase transformation; Substrate temperature; Annealing; Coating
Al-Cu-Cr quasicrystalline coatings were prepared with a special plasma spraying system developed by Dalian Maritime University, Plasma LE-15 with an internally fed-powder system and low power (2.5-8.0kW). Then the effects of substrate temperature during spraying and subsequent annealing on the phase transformation of quasicrystalline coatings were investigated.
