Aero-engine quality appraisal

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aerospace engine uses the synergy of high-temperature and high-pressure aerodynamics and advanced materials as its core principles. By optimizing the temperature in front of the turbine, compressor boost ratio and combustion efficiency, it achieves high thrust-to-weight ratio, low fuel consumption and ultra-long life. It is widely used in commercial airliners, military fighters, helicopters, drones and other fields. In wide-body passenger aircraft, it is used for continuous thrust output on transoceanic routes; in the field of fifth-generation fighters, it meets the dynamic needs of supersonic cruise and vector thrust; in civil aviation, it ensures the reliability of takeoff at high altitude airports. Compared with traditional engines, modern aero engines have the characteristics of single-crystal turbine blades, ceramic matrix composite materials and intelligent health management, and are the core driving force for aircraft safety and performance.

Zhongke Testing is a product quality appraisal service organization registered with the court. It can provide aero-engine quality appraisal services. It has a professional appraisal team and advanced instruments and equipment to provide fair and accurate appraisal results for aero-engine quality appraisal.

With the upgrade of aviation safety standards, related dispute cases have increased significantly. The judicial dispute focuses on:

1, performance index dispute: thrust-to-weight ratio does not meet the standard, turbine blade cooling efficiency is insufficient;

2, material defects: single crystal blade miscellaneous crystal defects, CMC coating peeling strength;

3, process problems: the residual stress of the high-pressure turbine disk exceeds the standard, and the floating wall of the combustion chamber is deformed after welding;

4, contract performance dispute: key materials (such as the replacement of third-generation powder metallurgy high-temperature alloys with second-generation) or software (such as FADEC control logic version) are not consistent with the technical agreement.

0 Such cases need to pass high temperature simulation testing, microstructure analysis and full life cycle verification to clarify the ownership of quality responsibility.

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Aviation engine quality identification technical methods include:

1. Appearance inspection: Check whether there are defects, corrosion or deformation marks on the engine surface.

2. Disassembly inspection: Disassemble the engine and check whether the internal parts are damaged, worn or deformed.

3. Performance test: Conduct performance test on the engine on the test bench to evaluate its thrust, speed, fuel consumption and other key parameters.

4. Durability testing: The engine is run for a long time to evaluate its fatigue resistance and vibration resistance.

05. Experimental data analysis: Analyze the test data to evaluate whether the engine performance meets the standard requirements.

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The applicant, an airline company, and the respondent, an engine manufacturer, signed a "LEAP-1A Engine Procurement Contract", stipulating that when the temperature in front of the turbine is 1,700°C, the blade life is ≥ 30,000 cycles. The blade broke prematurely during operation, and the manufacturer argued that it was caused by over-temperature operation.

Identification analysis results:

The quality analysis expert group discussed and comprehensively analyzed the relevant information of the "aeroengine", the contract technical agreement, the on-site inspection case materials and other data, and made the following quality analysis opinions:

The aerospace engine blade involved in the case had a processing deviation of cooling holes of ±0.05mm (agreed ±0.02mm), and the film cooling efficiency dropped by 30%; the local density of single crystal blades reached 8% (agreed ≤5%), resulting in a reduction in the creep life to 20,000 cycles; the PHM system did not promptly warn the metal of over-temperature (delay ≥5 seconds).

The appraisal conclusion determined that manufacturing process and material defects were the main reasons for the failure.

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The aerospace engine quality appraisal report should include:

1, the purpose of the appraisal (such as attribution of life disputes, airworthiness compliance verification) and cited standards (FAA AC 33-2, EASA CS-E, etc.);

2, engine model, serial number, maintenance records involved;

3, detection methods and equipment list (such as CT scanner, high temperature fatigue testing machine);

4, test data and failure correlation analysis (such as the impact of cooling efficiency on blade temperature);

05, clarify the quality responsibility determination conclusion and technical basis;

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26, signature of the appraiser, aerodynamic engineer qualification certificate and official seal of the organization.

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