The characteristics of heat treatment of aerospace parts are: strict temperature uniformity requirements (common Class 1–3 furnaces), the process must be strictly implemented according to specifications, each link is traceable, and data integrity and confidentiality requirements are high. The industry generally follows AMS2750 (pyrometry), AMS2759 series (heat treatment of steel, nitriding, etc.), and Nadcap special process certifications. Process control systems require high-precision measurement, automatic control, complete recording and tamper-proof data management.
- Temperature: strict furnace classification and uniformity, TUS/SAT
- Atmosphere: Carburizing and nitriding are automatically controlled according to specifications (such as AMS2759/10)
- Records: complete curve of each furnace, samples shipped with the furnace, inspection report
- Data: integrity, tamper resistance, permissions and confidentiality
- Certification: Nadcap Heat Treatment Special Process Audit
Characteristics of heat treatment of aviation parts
Once key parts such as aero engine shafts, gears, landing gear, and structural parts fail, the consequences will be serious. Therefore heat treatment requirements:
- process fixed: Execute strictly in accordance with the approved process specifications, and changes need to be reviewed;
- High precision temperature control: High requirements for furnace temperature uniformity and measurement accuracy;
- Comprehensive records: The process data and inspection results of each furnace and each batch can be traced;
- Personnel qualifications: Operation and inspection personnel need to be trained and qualified.
Main specifications
| Specification | Effect |
|---|---|
| AMS2750 | High temperature measurement: thermocouples, instruments, TUS, SAT, furnace classification |
| AMS2759 series | General requirements for heat treatment of steel parts and special specifications for carburizing, nitriding, nitrocarburizing, etc. |
| AMS2759/10、/12 | Gas nitriding and nitrocarburizing automatically controlled by nitriding potential (and carbon potential) |
| Customer specifications | OEMs often have stricter requirements for suppliers. |
| Nadcap | Certification of special processes run by industry organizations, heat treatment being an important category |
Process control requirements
temperature - Furnaces are classified by uniformity (common Class 1–3 for critical processes); - Conduct TUS and SAT at the specified frequency; - Thermocouple life and calibration are strictly managed.
atmosphere - Chemical heat treatments such as carburizing and nitriding use automatically controlled carbon potential and nitriding potential; - Atmosphere measuring instruments are calibrated regularly to ensure clear traceability.
Record - The temperature, atmosphere, time and load thermocouple data of each furnace are completely saved; - The test results of the samples shipped with the furnace are related to the furnace; - Records of handling exceptions and deviations.
Data integrity and confidentiality
Aerospace and defense related customers have additional data requirements:
- The original data cannot be tampered with, and revisions will leave traces;
- User permission classification and operation log;
- Data backup and long-term storage;
- Network isolation and access control when it comes to confidential projects.
Frequently asked questions
What does it take to enter the aerospace heat treatment supply chain?
It is usually necessary to meet quality management system requirements (such as aviation quality systems), pass customer audits, and obtain relevant special process certifications. The specific requirements are subject to customer requirements.
What are the difficulties in converting an automotive heat treatment plant into aerospace parts?
The main difficulties lie in temperature accuracy and instrument configuration, record integrity, documentation system and personnel qualifications. Equipment may need to be upgraded, and management systems may need to be rebuilt.
Is controlled nitriding necessary for aviation nitriding?
Many aviation regulations require automatic control of nitriding potential, and the traditional method of controlling only the decomposition rate often cannot be met.