Custom High Energy X-Ray Imaging specialists x

Setting a New Reference for Turbine Blade Measurement

  • Industry Served:
    Aerospace / Manufacturing
  • Technology:
    Digital Radiography / Computed Tomography
  • Products & Services:
    Three-dimensional thickness measurement / Detection of cracks and porosity
  • Customer Profile:
    A worldwide supplier of investment cast components for airplanes and industrial gas turbines
  • Business Challenge:
    Need for an effective inspection regimen to measure thickness and detect cracks and porosity in investment cast jet engine turbine blades to ensure they meet minimum thickness requirements and are free of defects
  • Solution:
    A flexible, five-axis system that provides both X-ray and computed tomography imaging, with automated analysis for pass/fail of turbine blades and components providing structural verification
  • Benefits:
    Increased quality of all parts produced, including mission-critical jet engine turbine blades, providing better protection of passengers and crew in the air / Eliminating the lost production time and extra cost of having to re-melt and recast parts after machining / Improved efficiency in the production process as inspections can be done quickly by line technicians using the intuitive system with automated image processing results

An advanced, high-energy X-ray system provides fast, thorough DR and CT inspection of investment cast jet engine turbine blades and other metal components, enhancing production quality and reducing rework

The Challenge

The Customer is a world leader in the investment casting of super alloys, aluminum and titanium components for jet aircraft and industrial gas turbine engines. Investment casting is based on a 5,000-year old metal forming technique known as “lost-wax casting” that relies on a wax form to shape a cast metal part. The technique is especially suited to casting complex shapes that are difficult to achieve with die casting.

With investment casting, there are always some dimensional variations in the cast parts that naturally occur. The Customer was charged with producing turbine blades to be used in the jet engines of one of its major clients, an aircraft manufacturer. After casting, the blades would be machined to refine their shape for use in the turbine engines.

As a component that is mission critical to the operation of the aircraft, the turbine blades have to be produced with absolute consistency. They need to be thin, for lightness, but also strong and durable, with a minimum thickness throughout the entire structure of the blade. The customer was measuring the blades after machining for structural verification before delivery to the aircraft manufacturer, but these inspections were finding that, after machining, some of the blades were now too thin.

Additionally, any cracks or porosity in the cast blades caused them to break during the machining process. The Customer was having to re-melt and recast too many of the parts, resulting in significant extra production time and cost. They needed a more effective pre-machining inspection approach.

The Adaptive Energy Solution

The Customer sought out Adaptive Energy for its expertise in delivering advanced X-ray digital radiography and computed tomography solutions. Adaptive Energy designed and installed a system providing both two-dimensional X-ray digital imaging and computed tomography (three-dimensional) imaging capabilities in a single unit.

The system uses X-rays as powerful as a 450 kV source, offering superior resolution and accuracy. A curved linear array detector optimizes the collection of X-ray images by eliminating the scatter phenomena that typically influence two-dimensional radiographs of blades and other metal parts.

It is a flexible system that can inspect small to large metal parts up to 24 inches (600 millimeters) in diameter and 24 inches in height. The linear detector has a greater than 80 percent quantum detection efficiency. The system has a five-axis fully programmable tray manipulator with precision ball screws and linear slides that allow each part to be positioned for thorough and accurate inspection from all angles.

The system provides fast data capture and produces high-quality, high-resolution digital images. A dedicated, custom-designed software application performs automated data and image processing, yielding pass/fail inspection results on each turbine blade, quickly and efficiently. The system is user friendly, and an embedded safety mechanism enables operation by line technicians—no special precautions are needed.

Results

With this system, the Customer has been able set a new reference for turbine blade measurement and perform non-destructive testing of small- to medium-size high-density metal parts and castings. In X-ray mode, test technicians can perform quick visual inspection of any suspect blade areas. CT mode allows for more in-depth analysis to assess thickness, cracking and porosity.

With the efficiency and automated inspection capabilities provided by the system, the Customer has been able to dramatically reduce rework of the turbine blades, saving time and money. At the same time, the system ensures the quality of these mission-critical jet engine parts, providing reliable operation and protecting the safety of aircraft passengers and crew while in the air.

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