Wang Le

Bio: Wang Le is an academic researcher from Nanchang University. The author has contributed to research in topics: Coating & Thermal barrier coating. The author has an hindex of 2, co-authored 17 publications receiving 19 citations.

Effect of Lanthanum Zirconate on High Temperature Resistance of Thermal Barrier Coatings

Abstract: Thermal barrier coatings (TBCs) typically have low thermal conductivity and high resistance to oxidation at elevated temperatures. TBCs are used to protect the turbine blades of aircraft engines op...

Effect of TGO on the tensile failure behavior of thermal barrier coatings

Abstract: Thermally grown oxide (TGO) may be generated in thermal barrier coatings (TBCs) after high-temperature oxidation. TGO increases the internal stress of the coatings, leading to the spalling of the coatings. Scanning electron microscopy and energy-dispersive spectroscopy were used to investigate the growth characteristics, microstructure, and composition of TGO after high-temperature oxidation for 0, 10, 30, and 50 h, and the results were systematically compared. Acoustic emission (AE) signals and the strain on the coating surface under static load were measured with AE technology and digital image correlation. Results showed that TGO gradually grew and thickened with the increase in oxidation time. The thickened TGO had preferential multi-cracks at the interface of TGO and the bond layer and delayed the strain on the surface of the coating under tensile load. TGO growth resulted in the generation of pores at the interface between the TGO and bond layer. The pores produced by TGO under tensile load delayed the generation of surface cracks and thus prolonged the failure time of TBCs.

Speckle marking method and coating material damage detecting method

Abstract: The invention discloses a speckle marking method and a coating material damage detecting method. The speckle marking method comprises steps: a type of a coating material is determined according to theroughness of the surface of the coating material; a speckle marking mode is selected according to the type of the coating material; and the selected speckle marking mode is adopted to mark nano-scalespeckles in a to-be-measured area of the coating material. According to the speckle marking method and the coating material damage detecting method disclosed in the invention, the nano-scale specklescan be marked in the to-be-measured area of the coating material, a basis is provided for measurement of a scanned image by a digital image correlation method at a nanometer level, and thus, the damage mechanism of the coating material can be inferred more accurately.

In-situ stretcher for coating material in-situ stretching observation system

Abstract: The invention discloses an in-situ stretcher for a coating material in-situ stretching observation system. The in-situ stretcher comprises a worktable, a movable object stage, a fixed object stage anda driver, wherein the movable object stage is movably arranged on the worktable, and is suitable for fixing one end of a sample substrate coated with a to-be-detected coating; the fixed object stageis mounted on the worktable and is fixed relative to the worktable, the movable object stage is moved to adjust the distance with the fixed object stage, and the fixed object stage is suitable for fixing the other end of the sample substrate coated with the to-be-detected coating; the driver is mounted on the worktable and in transmission connection with the movable object stage. The in-situ stretching machine for the coating material in-situ stretching observation system of the embodiment has a smaller size while realizing stretching of the to-be-detected material, and can be placed in a scanning electron microscope for observation accordingly, and initiation and growth mechanisms of cracks and the damage mechanism of the material in the stretching process of a coating material can be analyzed conveniently.

Fatigue test method for coating material

Abstract: The invention discloses a fatigue test method for a coating material, which comprises the following steps: selecting a sample matrix; spraying a coating material to be observed on the sample matrix; carrying out speckle marking on the coating material; sending the sample matrix sprayed with the coating material into a scanning electron microscope; intermittently stretching the sample substrate andthe coating material thereon; and continuously shooting images or carrying out whole-process video recording on the coating material by using the scanning electron microscope. According to the fatigue test method for the coating material, the practical application environment of the coating material can be simulated more closely, the cracking process of the coating material can be observed in detail, and the crack initiation and expansion mechanism of the coating material in the stretching process and the damage mechanism of the material can be analyzed conveniently.

Laser cladding process of Cobalt and Nickel based hard-micron-layers on 316L-stainless-steel-substrate

Abstract: In the present study, two different types of coatings such as Cobalt (Co-Cr-W-C) and Nickel (Ni-Cr-B-Si-C) based layers have produced using a high power of Ytterbium-doped yttrium aluminum garnet (...

Enhancing the thermal insulating properties of lanthanum zirconate porous ceramics via pore structure tailoring

Abstract: The potentially useful role of lanthanum zirconate (La2Zr2O7, LZO) porous bulk ceramics has been rarely explored thus far, much less the optimisation of its pore structure. In this study, LZO porous ceramics were successfully fabricated using a tert-butyl alcohol (TBA)-based gelcasting method, and the pore structures were tailored by varying the initial solid loading of the slurry. The as-prepared ceramics exhibited an interconnected pore structure with high porosity (67.9 %–84.2 %), low thermal conductivity (0.083–0.207 W/(m·K)), and relatively high compressive strength (1.56–7.89 MPa). The LZO porous ceramics with porosity of 84.2 % showed thermal conductivity as low as 0.083 W/(m·K) at room temperature and 0.141 W/(m·K) at 1200 °C, which is much lower than the counterparts fabricated from particle-stabilized foams owing to its unique pore structure with a smaller size, exhibiting better thermal insulating performance.