Microstructure and sliding wear behavior of pseudo-alloy PS45/CuAl8 composite coating sprayed by HVAA technique

A pseudo-alloy PS45/CuAl8 composite coating was sprayed on steel substrate by high-velocity activated arc spraying (HVAA) process. Its sliding wear behavior at room temperature was evaluated by M-2000 wear tester. For comparison, a single CuAl8 coating was also prepared and tested under the same conditions. It is found that the pseudo-alloy composite coating consists of α-Cu and γ-Ni metallic matrix phases together with homogenously distributed minor Al 2 O 3 , Cr 2 O 3 oxide phases. Moreover, pseudo-alloy coating possesses much better sliding wear resistance than CuAl8 coating due to the enhanced hardness and microstructural homogenization. Fatigue wear and abrasive wear are responsible for the wear-down mechanism of the pseudo-alloy coating.

PS45/CuAl8伪合金复合涂层高温循环氧化行为

采用超音速活性电弧喷涂技术在Q235钢基体表面制备PS45/CuAl8伪合金复合涂层,将该涂层在600℃和800℃进行循环氧化,采用XRD、SEM和精密天不等手段对涂层的显微结构进行表征,研究了涂层的循环氧化性能。结果表明:PS45/CuAl8伪合金复合涂层主要由Al_2O_3、Cr_2O_3、α-Cu和γ-Ni固溶体组成,组织致密,颗粒成扁平状且扁平化程度高、分布均匀。经高温循环氧化后在涂层表面形成了一层致密的Al_2O_3+Cr_2O_3+Ni(Al,Cr)_2O_4薄膜,避免了Al_2O_3薄膜的剥落,从而降低了涂层氧化速率,提高了基体的抗高温循环氧化性能。

基体温度对PS45-CuAl8伪合金复合涂层性能的影响

采用超音速活性电弧喷涂技术在Q235钢基体上制备PS45-CuAl8伪合金复合涂层,采用万能试验机和维氏硬度计等手段对涂层的组织结构及物理性能进行表征,并研究了基体温度对PS45-CuAl8伪合金复合涂层性能和结构的影响。结果表明,随着基体温度由30℃提高到270℃,喷涂粒子扁平化程度加大以及表面吸附水膜的挥发使得涂层沉积率由40%提高到50.3%,涂层与基体的结合强度则从33.1 MPa增加到40.3 MPa。