טכניון מכון טכנולוגי לישראל
הטכניון מכון טכנולוגי לישראל - בית הספר ללימודי מוסמכים  
M.Sc Thesis
M.Sc StudentHarel Orit
SubjectCertification for Heat Treating Process in 'Carmel Forge'
Factory
DepartmentDepartment of Quality Assurance and Reliability
Supervisor Dr. Jacqueline Asscher


Abstract

Carmel Forge Ltd. is a forging house producing disks and rings for the aero engine industry.

Since 1994 the factory is owned by Pratt & Whitney, an international company, building aero engines.

Pratt & Whitney has developed the "achieving competitive excellence ) ACE) standard", a standard dealing with managing quality systems for the aviation industry.

The purpose of this project is to prepare the thermal treatment process for certification according to the ACE standard, by planning and implementing statistical process control (SPC).

The first step was gathering relevant data. The thermal treatment process is critical for setting the metallurgical properties of the parts. The following quality characteristics were examined: 

 temperature, time and transfer time.

Analysis of the measurement results according to the Gage Repeatability and Reproducibility (GR&R) method indicated a problem in the measurement systems of temperature and time.

Statistical process control was carried out for each quality characteristic. Appropriate control charts were constructed and capability indices were calculated. Out of control deviations and trends were investigated.

A proposal for on line SPC was developed and an analysis of the sources of variation was performed in order to improve process quality. The analysis of variance results showed that a majority of the variation originates from natural process variation.

Practical suggestions were made in order to improve the process and the statistical control.

The thermal treatment process was certified to the ACE standard on March 2004.