Aerothermodynamics of Aircraft Engine Components

1985 ◽  
Keyword(s):  
Aircraft Engine ◽  
Engine Components

scholarly journals Repair of Precision Castings Made of the Inconel 713C Alloy

2017 ◽  
Vol 17 (3) ◽  
pp. 210-216
Author(s):  
K. Łyczkowska ◽  
J. Adamiec
Keyword(s):  
Model Test ◽  
Aircraft Engine ◽  
Casting Defects ◽  
Exhaust Gas ◽  
Plasma Arc ◽  
Nickel Based Superalloy ◽  
Melted Zone ◽  
Base Materials ◽  
Inconel 713C ◽  
Engine Components

Abstract Inconel 713C precision castings are used as aircraft engine components exposed to high temperatures and the aggressive exhaust gas environment. Industrial experience has shown that precision-cast components of such complexity contain casting defects like microshrinkage, porosity, and cracks. This necessitates the development of repair technologies for castings of this type. This paper presents the results of metallographic examinations of melted areas and clad welds on the Inconel 713C nickel-based superalloy, made by TIG, plasma arc, and laser. The cladding process was carried out on model test plates in order to determine the technological and material-related problems connected with the weldability of Inconel 713C. The studies included analyses of the macro- and microstructure of the clad welds, the base materials, and the heat-affected zones. The results of the structural analyses of the clad welds indicate that Inconel 713C should be classified as a low-weldability material. In the clad welds made by laser, cracks were identified mainly in the heat-affected zone and at the melted zone interface, crystals were formed on partially-melted grains. Cracks of this type were not identified in the clad welds made using the plasma-arc method. It has been concluded that due to the possibility of manual cladding and the absence of welding imperfections, the technology having the greatest potential for application is plasma-arc cladding.

Probabilistic Fretting Fatigue Assessment of Aircraft Engine Disks

2009 ◽  
Author(s):  
Michael P. Enright ◽  
Kwai S. Chan ◽  
Jonathan P. Moody ◽  
Patrick J. Golden ◽  
Ramesh Chandra ◽  
...  
Keyword(s):  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Gas Turbine ◽  
Crack Growth ◽  
Stress Gradient ◽  
Random Variables ◽  
Aircraft Engine ◽  
Fretting Fatigue ◽  
Turbine Engine ◽  
Engine Components

Fretting fatigue is a random process that continues to be a major source of damage associated with the failure of aircraft gas turbine engine components. Fretting fatigue is dominated by the fatigue crack growth phase and is strongly dependent on the magnitude of the stress values in the contact region. These stress values often have the most influence on small cracks where traditional long-crack fracture mechanics may not apply. A number of random variables can be used to model the uncertainty associated with the fatigue crack growth process. However, these variables can often be reduced to a few primary random variables related to the size and location of the initial crack, variability associated with applied stress and crack growth life models, and uncertainty in the quality and frequency of non-deterministic inspections. In this paper, an approach is presented for estimating the risk reduction associated with non-destructive inspection of aircraft engine components subjected to fretting fatigue. Contact stress values in the blade attachment region are estimated using a fine mesh finite element model coupled with a singular integral equation solver and combined with bulk stress values to obtain the total stress gradient at the edge of contact. This stress gradient is applied to the crack growth life prediction of a mode I fretting fatigue crack. A probabilistic model of the fretting process is formulated and calibrated using failure data from an existing engine fleet. The resulting calibrated model is used to quantify the influence of inspection on the probability of fracture of an actual military engine disk under real life loading conditions. The results can be applied to quantitative risk predictions of gas turbine engine components subjected to fretting fatigue.

S0405-2-4 Strength evaluation of CMC aircraft engine components

2009 ◽  
Vol 2009.1 (0) ◽  
pp. 321-322
Author(s):  
Yuki NONAKA ◽  
Hiroshige MURATA ◽  
Takeshi NAKAMURA
Keyword(s):  
Aircraft Engine ◽  
Strength Evaluation ◽  
Engine Components

New Arc Wire Approvals for Aircraft Power Plant Overhaul

2000 ◽  
Author(s):  
E.R. Sampson ◽  
P. Sahoo
Keyword(s):  
Aircraft Engine ◽  
Historical Background ◽  
Spray Process ◽  
Arc Spray ◽  
Auxiliary Power ◽  
Auxiliary Power Units ◽  
Plasma Sprayed Coatings ◽  
Plasma Sprayed ◽  
Engine Components ◽  
Aircraft Overhaul

Abstract Arc spray systems are increasingly used in the overhaul of aircraft engine components and auxiliary power units. The increasing use of arc spray over plasma for metallic coatings has created a demand for new wire approvals. The chemistry is already established as a powder and it is a matter of conversion to a wire and the arc spray process. The increasing popularity of the arc spray process is due to its superior bond strength and microstructure that exceed those of plasma. In one case, there is a two and one-half percent porosity requirement for the arc spray and up to 15% is allowed for plasma. This density approaches HVOF quality requirements. This paper will discuss some historical background of the process, what is approved and then move on to the new materials that are submitted for approval. Microstructures and bond strengths will be presented and some information about a proprietary method to solve a coating problem in the aircraft overhaul industry of long standing. The paper will also discuss new advances in arc spray systems and materials, which makes these systems amenable to replacing plasma sprayed coatings.

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