CAJ | 학술논문

目的：研究等离子喷涂NiCoCrAlY/Al2 O3高温固体润滑耐磨涂层在850℃时的高温抗氧化性能和抗氧化机理。方法采用喷雾造粒、化工冶金包覆技术制备NiCoCrAlY/Al2 O3复合粉体,并采用等离子喷涂技术在45#钢表面制备NiCoCrAlY/Al2 O3复合涂层。采用SEM和XRD研究粉体和涂层的显微结构和物相组成,并采用马弗炉研究复合涂层在850℃的恒温氧化动力学曲线,通过研究氧化96 h以后涂层表面的组织形貌,探讨NiCoCrAlY/Al2 O3复合涂层的抗氧化机理。结果 NiCoCrAlY合金层均匀致密地包覆在Al2 O3颗粒的表面,包覆层厚度约为3~5μm。复合粉体的主要组成为Al2 O3相和NiCoCrAlY合金相,没有其他杂质相的存在。等离子喷涂NiCoCrAlY/Al2 O3复合涂层氧化动力学曲线分为大斜率直线、抛物线和系数几乎为0的抛物线等3个阶段。氧化96 h以后,涂层的氧化质量增量为4.9 mg/cm2左右,表面形成了一层连续的氧化物保护膜,经EDX分析,氧化膜层主要由Al,O,Cr和Ni组成。结论等离子喷涂NiCoCrAlY/Al2 O3复合涂层具有良好的高温抗氧化性能,涂层中Ni,Cr,Al的氧化以及硬质相Al2 O3的加入是涂层抗氧化的主要原因。
목적：연구등리자분도NiCoCrAlY/Al2 O3고온고체윤활내마도층재850℃시적고온항양화성능화항양화궤리。방법채용분무조립、화공야금포복기술제비NiCoCrAlY/Al2 O3복합분체,병채용등리자분도기술재45#강표면제비NiCoCrAlY/Al2 O3복합도층。채용SEM화XRD연구분체화도층적현미결구화물상조성,병채용마불로연구복합도층재850℃적항온양화동역학곡선,통과연구양화96 h이후도층표면적조직형모,탐토NiCoCrAlY/Al2 O3복합도층적항양화궤리。결과 NiCoCrAlY합금층균균치밀지포복재Al2 O3과립적표면,포복층후도약위3~5μm。복합분체적주요조성위Al2 O3상화NiCoCrAlY합금상,몰유기타잡질상적존재。등리자분도NiCoCrAlY/Al2 O3복합도층양화동역학곡선분위대사솔직선、포물선화계수궤호위0적포물선등3개계단。양화96 h이후,도층적양화질량증량위4.9 mg/cm2좌우,표면형성료일층련속적양화물보호막,경EDX분석,양화막층주요유Al,O,Cr화Ni조성。결론등리자분도NiCoCrAlY/Al2 O3복합도층구유량호적고온항양화성능,도층중Ni,Cr,Al적양화이급경질상Al2 O3적가입시도층항양화적주요원인。
ABSTRACT:Objective To study the oxidation resistance and oxidation-resistance mechanism of atmospheric plasma-sprayed NiC-oCrAlY/Al2 O3 wear-resistant coatings at 850℃. Methods The NiCoCrAlY/Al2 O3 composite powder was prepared by the technolo-gy of spray granulation, chemical and metallurgical coating and solid state alloying. The NiCoCrAlY/Al2 O3 composite coating was prepared by atmospheric plasma-spray technology using the prepared powder on the surface of 45# steel. The microstructure and phase composition of the powder and coating were studied by SEM and XED. The oxidation kinetic curve at constant 850 ℃ was explored with muffle furnace and the oxidation resistance mechanism of the APS sprayed NiCoCrAlY/Al2 O3 composite coatings was investigated through analysis of morphology of the coating surface after 96 h of oxidation. Results The Al2 O3 was evenly and closely coated with NiCoCrAlY alloy and the thickness of NiCoCrAlY alloy was 3 ~5 μm. The phase compositions of composite powder were mainly NiCoCrAlY and Al2 O3 without other impurities. The oxidation kinetics curves of the coatings can be divided into three stages:severely sloping, parabolic and slightly parabolic stages. The value of oxidation weight gain was about 4. 9 mg/cm2 after 96 h of oxidation. The oxide film was formed and the phase compositions of oxide film were Al,O, Cr and Ni according to the EDX a-nalysis. Conclusion The NiCoCrAlY/Al2 O3 composite coating exhibited excellent oxidation resistance property. The reason of oxi-dation resistance of the coating was the oxidation of Ni, Al and the addition of Al2 O3 .