JIA Xiao-hui,HU Ya-bao,SONG Xin-ling,FANG Yan,LEI Jian-bo.Microstructure and Wear Performance of WC/Inconel 718 Composites by Laser Melting Deposition[J],51(12):329-339
Microstructure and Wear Performance of WC/Inconel 718 Composites by Laser Melting Deposition
  
View Full Text  View/Add Comment  Download reader
DOI:10.16490/j.cnki.issn.1001-3660.2022.12.034
KeyWord:laser melting deposition  Inconel 718  tungsten carbide  microstructure  wear mechanism
              
AuthorInstitution
JIA Xiao-hui Laser Technology Institute, Tiangong University, Tianjin , China
HU Ya-bao Laser Technology Institute, Tiangong University, Tianjin , China
SONG Xin-ling Laboratory of Mechanics Gabriel Lamé LaMé, University of Orleans, Orleans 45072, France
FANG Yan Laser Technology Institute, Tiangong University, Tianjin , China
LEI Jian-bo Laser Technology Institute, Tiangong University, Tianjin , China
Hits:
Download times:
Abstract:
      As one of the most widely used nickel-based alloys in the aerospace field, Inconel 718 alloy has good strength and mechanical properties at high temperature and room temperature, and has been widely used in military applications, aerospace aircraft and various parts and components. However, after long-term service in harsh working environments, aircraft engine components often face problems such as blade wear, and serious failures will reduce the performance of the components, thereby affecting the service life of the components. The work aims to solve the wear failure of Inconel 718 alloy in engineering application, and explore the mechanism of WC in enhancing the wear resistance of Inconel 718 alloy. The Inconel 718 and WC/Inconel 718 coatings were prepared by laser melting deposition technology. The microstructure evolution mechanism, hardness, friction and wear properties and WC strengthening mechanism of WC composite Inconel 718 alloy were studied. The WC/Inconel 718 composite powders were mixed uniformly by a mixer. Before the laser melting deposition experiments, the Inconel 718 and WC/Inconel 718 powders were dried in a drying oven at 110 ℃ for 2 h to remove the internal moisture. The substrate was A3 steel plate, the surface of the substrate was cleaned with sandpaper and a laser cleaning machine to remove oxides and rust on the surface to prevent affecting the experimental results. The powders and the laser enter the molten pool together through the laser working head, and were melted on the A3 steel substrate under the action of the laser. The whole cladding experiment was carried out under the protection of an argon gas chamber. The processing parameters were:the laser scanning speed was 16 mm/s, the laser power was 2 000 W, and the overlap rate was 50%. According to the metallographic preparation standards, the prepared Inconel 718 and WC/Inconel 718 cladding blocks were cut, ground and polished, and the samples were corroded with a corrosive solution of HCl:HF=1∶1, the German ZEISS-Sigma 300 field Scanning electron microscopy (SEM) was used to observe the microstructure and morphology of the cross-section of Inconel 718 alloy and WC/Inconel 718 composite, and then the equipped energy dispersive spectrometer (EDS) was used to analyze the element distribution in specific positions of the samples. The phases of Inconel 718 and WC/Inconel 718 samples were detected by D/MAX-2500 X-ray diffractometer, respectively. Using a microhardness tester (HV-1000 Vickers hardness tester) with a load of 0.2 kg and a loading time of 10 s, the cross-section of the sample was measured from the coating surface at a certain distance along the deposition direction. Friction and wear experiments were carried out on Inconel 718 alloy and WC/Inconel 718 composite specimens at room temperature using M-2000 type test block-pair grinding ring wear tester and the wear debris was collected. The microstructure of the coatings were mainly composed of columnar crystals and cellular crystals. The phase composition of Inconel 718 alloy mainly consists of γ-(Ni, Fe), γ′-Ni3 (Al, Ti) and Fe3Ni2, the phase composition of WC/Inconel 718 mainly consists of γ-(Ni, Fe), γ′-Ni3(Al, Ti), AlCoCrW, CrNi15W and Cr-Ni-Fe-C; The hardness test and friction and wear test were carried out on Inconel 718 alloy and WC/Inconel 718 composite materials. The experimental results showed that WC slightly increased the hardness of the alloy, and the wear rate was reduced to 65.3% of that of the alloy without WC. This is because the WC particles play a role of strengthening the hard particles in the Inconel 718 matrix, and the dissolution of a small amount of WC particles increases the hardness of the alloy matrix. In addition, the generated high-hardness metal compound and undissolved spherical WC particles have a pinning effect that hinders the movement of the grain boundary, which is very helpful to improve the wear performance of Inconel 718 alloy.
Close