Cheng-cheng Zhang

AECC Commercial Aircraft Engine Co. Ltd · R&D Center Dept. of Discipline Engineering

This study investigates the influence of two-phase powder feeding spacing on the thermal cycling and CMAS corrosion resistance of the thermal barrier coatings (TBCs). Porous thermal barrier coatings with varying microstructures were prepared using the embedded micro agglomerated particle (EMAP) coating preparation method, which is based on conventi...

In the present work, a new surface mechanical strengthening (SMS) technique named stress ultrasonic rolling (SUR), which is ultrasonic rolling (UR) assisted with a uniaxial tensile elastic stress field, was reported and successfully conducted on 5 % wt TiB 2 /7050Al composite. Based on the experimental analysis and numerical simulation , the effect...

The development of gas turbine technology has led to an increase in the complexity of the geometric shape of the sprayed workpiece. Consequently, it has become more difficult to maintain the perpendicularity of the spraying angle during the spraying process, thereby impacting the structure and performance of the coating. This study uses the atmosph...

The influences of surface integrity on the fatigue performance of in-situ 6 wt% TiB2/2024Al composite treated by ultrasonic deep rolling (UDR) were comprehensively investigated with both experiments and simulations. Results reveal that only a single pass of UDR treatment can impressively reduce the surface roughness of the fine-turned specimens by...

Thermal barrier coatings (TBCs) material has excellent high-temperature resistance and heat insulation performance, which plays a vital role in improving the working efficiency and running life of the engine. During the flight, the engine will inhale dust particles in the air. These particles are mostly from siliceous debris, which are usually call...

Enhancing the high temperature mechanical properties and the thermal stability of aluminum alloys are in urgent demand for the lightweight application scenarios (such as pistons, fan blades, crankshafts) working at elevated temperatures. The fabrication of aluminum matrix composites is a promising solution. In this work, TiB2 nanoparticles were in-...

Residual stresses and strain hardening in GH4169 Ni-based superalloy treated by four different laser shock peening (LSP) configurations and their thermal evolution behaviors under two vacuum annealing conditions were investigated with X-ray diffraction (XRD) and two uniaxial progressive loading tests with two loading rates. Results showed that the...

A micro‐agglomerated particle embedded–thermal barrier coating (TBC) structure was prepared by an improved plasma spray process to withstand the sintering‐induced degradation of TBCs during service. In this study, the sintering resistance and thermophysical and mechanical properties of conventional and novel‐structured TBCs were systematically char...

As a vital component of aero-engine, blade is susceptible to damage from long-term service under cyclic loads. Ultrasonic impact treatment (UIT) can improve the mechanical properties of the material surface. However, applying UIT onto aero-engine blade remains a challenge due to the complex structure. This study investigates robot-assisted ultrason...

Stress distribution has a significant effect on crack nucleation and propagation in thermal barrier coatings (TBCs). The stress distribution of different types of double-layer plasma-sprayed coatings, such as YbYSZ/YSZ (YbYSZ: Yb2O3-Y2O3 co-stabilised ZrO2; YSZ: Y2O3 stabilised ZrO2) and YbYSZ/EMAP-YSZ (EMAP-YSZ: embedded micron-agglomerated partic...

Residual stresses are one of the main factors determining the failure of aircraft engine materials. It is not possible to reliably and accurately predict the remaining service life of aircraft engine components without properly accounting for the presence of residual stresses. The absolute level and spatial distribution of the residual stress is un...

Many high-temperature rotating components are always subjected to complex loading waveforms, arising the concerns for multi-damage driving crack initiation. In this paper, a series of strain-controlled low cycle fatigue (LCF) and creep-fatigue interaction (CFI) tests as well as the novel creep-fatigue combined with high-low cycle (CF-HL) tests were...

Gadolinium zirconate (GZ) has become a promising thermal barrier coating (TBC) candidate material for high-temperature applications because of its excellent high-temperature phase stability and low thermal conductivity compared to yttria-stabilized zirconia (YSZ). The double-ceramic-layered (DCL) coating comprised of GZ and YSZ was confirmed to pos...

Waterjet peening has emerged as a potential surface treatment technology, which is gradually being used to improve the surface integrity and mechanical behavior of metal materials. Submerged abrasive waterjet peening, which combines cavitation peening and abrasive waterjet peening and called cavitation abrasive integrated waterjet peening (CAI-WJP)...

Solution precursor plasma spray (SPPS) can prepare thermal barrier coatings (TBCs) with nanostructures, which can modify the adhesion and wettability of molten silicate environmental deposits (CMAS) on the surface of TBCs, thereby improving the resistance of TBCs to CMAS corrosion. In this study, SPPS layers with micro-nano double scale structures...

The novel surface nano-crystallization ultrasonic rolling process (USRP) technology is used to improve the surface integrity of Al-based TiB2/Al composite and widen potential applicability in this work. Based on self-developed two generations of USRP devices, the basic attempts to processing parameters are conducted to qualitatively link up with th...

Quench-induced S(Al2CuMg) phases are generally formed in Al-Zn-Mg-Cu alloys. The precipitation and relative crystallographic relationships of η-type (MgZn2) precipitates at the interfaces between the quench-induced S phases and Al matrix were studied in an Al-Zn-Mg-Cu alloy by coupling Cs-corrected scanning transmission electron microscopy (STEM) w...

Complex effects of reinforcements on the fatigue crack growth behavior in a wrought Al matrix composite were quantificationally studied by hierarchical characterizations in consideration of particle bands. The results show that crack growth mechanisms of the composite does not only inherit the effect of matrix microstructures, but also significantl...

Ultrasonic surface deep rolling (USDR), oxygen boost diffusion (OBD), and their combination (USDR-OBD) were all used to improve the surface hardening of pure titanium. The microstructure, microhardness, and fatigue life of pure titanium treated by USDR, OBD, and USDR-OBD methods were analyzed. USDR treatment induced a severe deformation area, while...

A new creep–fatigue damage cumulative model is proposed under multiaxial thermomechanical random loading, in which the damage at high temperature can be divided into the pure fatigue damage and the equivalent fatigue damage from creep. During the damage accumulation process, the elementary percentage of the equivalent fatigue damage increment is pr...

As crucial parts of an aeroengine, blades are vulnerable to damage from long-term operation in harsh environments. The ultrasonic surface rolling process (USRP) is a novel surface treatment technique that can highly improve the mechanical behavior of blades. During secondary machining, the nominal blade model cannot be used for secondary machining...

Security and performance of aircraft engines are extremely affected by the blades’ surface quality. Ultrasonic surface rolling process (USRP) can improve material surface properties effectively and increase the alloys’ service life. However, applying USRP onto blades remains a challenge due to the free-form surface with thin-walled leading/trailing...

A fatigue–oxidation–creep damage model that can take into account the effect of multiaxial cyclic feature on the damage mechanism is proposed under axial-torsional thermo-mechanical fatigue loading. In the proposed model, the effects of non-proportional additional hardening on fatigue, oxidation, and creep damages are considered, and the variation...

A crystal plasticity model is developed to predict the cyclic plasticity during the low cycle fatigue of GH4169 superalloy. Accumulated plastic slip and energy dissipation as fatigue indicator parameters (FIPs) are used to predict fatigue crack initiation and the fatigue life until failure. Results show that fatigue damage is most likely to initiat...

GH4169 at 650 °C in atmosphere was investigated by using single edge notch tensile specimens. The number of main cracks and crack initiation mechanisms at the notch surface strongly depended on the grain size. The crack initiation life accounted for more percentages of the total fatigue life for the alloy with smaller grain size. The fatigue life g...

The multiaxial thermomechanical fatigue properties for nickel-based superalloy GH4169 in aeroengine turbine discs are investigated in this paper. Four types of axial–torsional thermomechanical fatigue experiments were performed to identify the cyclic deformation behavior and the damage mechanism. The experimental results showed that the creep damag...

Titanium and its alloys are widely used in aerospace, biomedicine, chemical industries, and other fields due to the excellent properties as high specific strength, strong corrosion resistance, and superior biocompatibility. With the development of mechanical industry, especially of aerospace, the higher fatigue performance of titanium alloys is dem...

The microstructural evolution of pure nickel treated by deep rolling (DR) technique with different indent depths was investigated by means of optical microscopy and transmission electron microscopy. The surface roughness, hardness and residual stress distribution along the depth from surface were measured. Moreover, the DR-treated sample was anneal...

The aim of this paper was to investigate the effect of thermal annealing on the microstructure, mechanical properties, and residual stress relaxation of deep rolled pure titanium. The microstructure and mechanical properties of the surface modified layer were analyzed by metallographic microscopy, transmission electron microscope and in-situ tensil...

A dovetail fixture for fretting fatigue test was designed. Fretting fatigue experiments were performed for Ni-based single crystal (NBSX) superalloys at 600 and 700 °C in two secondary orientations, [110] and [010]. The influence of secondary orientation and temperature on fretting fatigue behavior was investigated. The crystal plasticity finite el...

Based on the isothermal fatigue and creep damage, a life prediction approach under multiaxial thermo-mechanical loading was proposed in this investigation. In the proposed method, the multiaxial thermo-mechanical fatigue damage during one cycle period was divided into the isothermal fatigue damage and the creep damage. In order to evaluate conserva...

The aim of this paper is to investigate different factors, including dwell time, strain range, and strain ratio on creep-fatigue endurances in nickel-based Inconel 718 and GH4169 superalloys. We also summarize classic approaches for life assessments based on the generalizations of Coffin-Manson equation, linear damage summation (LDS), and strain-ra...

Fatigue life prediction Microstructural dissimilitude Nickel-based alloy A B S T R A C T This paper was concerned with an approach to predict fatigue life based on a multi-scale crack propagation model. The expressions of crack propagation rates in microstructurally small crack (MSC), physically small crack (PSC) and long crack (LC) stages were uni...

The low cycle fatigue (LCF) and creep-fatigue behaviors of Ni-based GH4169 superalloy are investigated by uniaxial strain-controlled fully-reversed testing at 650 °C. Compared with LCF tests, the effects of tensile and compressive strain hold times on creep-fatigue lifetimes are experimentally explored with varying total strain ranges in the presen...

The aim of this paper is to investigate different factors, including dwell time, strain range, and strain ratio on creep-fatigue endurances in nickel-based Inconel 718 and GH4169 superalloys. We also summarize classic approaches for life assessments based on the generalizations of Coffin-Manson equation, linear damage summation (LDS), and strain-ra...

The axial-torsional thermo-mechanical fatigue behavior for Ni-based superalloy GH4169 was investigated experimentally in the temperature interval from 360 °C to 650 °C. The experimental results showed that, in the same von Mises equivalent mechanical strain amplitude condition, the fatigue life can be seriously decreased when the axial mechanical s...

Rotary-bending fatigue tests of Ti-6Al-4V alloy at very high-cycle regime were performed in air and 3.5% NaCl solution, respectively. The S-N curves exhibited the characteristic of horizontal asymptote (traditional fatigue limit) in laboratory air, while a lower fatigue limit was shown in 3.5% NaCl solution after around 3 × 108 cycles. The decrease...

The fatigue crack growth behavior of the newly developed GH4169 nickel-based alloy at a maximum stress of 700 MPa and different stress ratios was investigated in the present work employing the specimens with a single micro-notch at a frequency of 129 Hz at room temperature. The results demonstrate a typical three-stage process of fatigue crack prop...

The stages of fatigue crack initiation and small crack propagation usually occupy most part of fatigue life. The multi-scale fatigue crack propagation mechanism of 304 stainless steel using in situ optical microscopy was investigated in this paper. An analytical model was also proposed to predict the multi-scale crack growth rate. Results indicated...

Fatigue crack growth behaviours of the titanium alloy Ti-6Al-4V, with two different microstructures, at different maximum stresses were identified by digital image correlation technique. Full-field strains were monitored around fatigue cracks after consecutive cycles in fatigue crack growth experiments. Results indicated that the Ti-6Al-4V alloy wi...

The effect of volume fraction of δ phase, which was changed through changing the heat treatment conditions, on the strain-controlled fatigue behavior of Nickel-based GH4169 alloys at room temperature was investigated. The δ phase had almost no effect on fatigue life at strain amplitude higher than 0.5%. However, the fatigue life increased with incr...

The purposes of the present work are to extend the previous energy-based model on the basis of strain energy density exhaustion and to estimate creep-fatigue endurance and accumulated damage using cycle-by-cycle concept in tension-hold-only tests. The nickel-based GH4169 superalloy at 650 °C is employed to fit material constants and to verify the p...

The failure of dual-phase alloys under tensile loading conditions is often due to the nucleation, growth and coalescence of voids at the interface between different phases from micromechanical point of view. The aim of this paper is to identify the failure mechanism and mode of dual-phaseTi-6Al-4V alloy in the form of plastic strain localization du...

Current design methodologies for LCF/HCF of aero engine components are based on traditional uniaxial stress/strain methods like strain-life (ε-N), stress-life (S-N) and Goodman / Haigh diagram approaches, often applied with a wide safe factors to account for uncertainties in the understanding of multiaxial loading and other effects. With constantly...

The traditional stress severity factor (SSF) approach is almost unable to obtain the SSF value under complex geometry and loading boundaries. The maximum stress at the edge of a hole can be obtained easily by 3D FEM, but the process is time-consuming if the quality and filling status of the pin-loaded holes are included in the FE model; moreover, t...