Cold Spray Landing Gear Repair

In by Chris Garville

Image

Cold Spray Landing Gear Repair

F5/T38 Repair & Overhaul

Download Hard Copy
Image
COC Aerospace - Proprietary and Confidential Company Information

AS9100D

COC Aerospace has developed a repair for F-5 landing gear components

F-5 landing gears have tight tolerances with regards to repairs.

Example is the Main Landing Gear Cylinder and Nose Landing Gear Cylinder.

  • Tight tolerances for the main upper cylinder bore diameter are from 3.000 to 3.004.
  • Scratches and gouges need to be removed.
  • Some gouges exceed 3.004 requiring the cylinder honed until it is oversized.
  • Hard anodizing with will not provide enough build-up to achieve a bore of 3.004 or less.
Image

Cold Spray Defined

Is an Additive Manufacturing Process.

Does not induce thermal stresses into the parent or deposited material.

Image

Metallurgical testing the Cold Spray of Main Landing Gear Cylinder; P/N 14-40602

Test coupon of main landing gear cylinder gun-drilled, cold sprayed, cut into sections and tested every 2-3 inches for molecular adhesion, hardness, macro-micro inspections.

Image
Image
Image

Preparing cylinder for Cold Spray.

Cylinder is gun drilled (honed) .005 – 008” to remove all damage to inside walls.

Image
Image

Cold Spraying inside of MLG Cylinder

Using COC-developed long-reach nozzle and ‘turntable’ that rotates the cylinder at the correct speed for the Cold Spray application.

The powder has a bond strength of 6,000 psi (ASTM-C633). Porosity >1% (MIL-STD-3021, Hardness: 91 HR-15Y, AI02 content 8-16%.

Image
Image
Image

Inner bore of MLG Cylinder is then re-honed back to the newly manufactured tolerances

Image
Image

Nickel-based Spraying

Cylinders are sprayed with a nickel-based material that is more durable than the 7075 aluminum.

Surface finish of the cylinder walls are 12-14, twice as smooth as T.O. requirement of 32.

Image
Image

Cylinders are honed after cold spray to 3.000-3.001”, back to original specifications

Image
Image

Inspection and Preparation

Cylinders are penetrant inspected, anodized and prepared for painting.

Dimensions are checked with digital bore gauge.

Image
Image

Outer Surface Finish

Outer cylinder Cold Spray is used to repair damage to outer surfaces of MLG Cylinder.

The areas are blended back to original dimensions.

Image
Image

COC’s Cold Spray MLG Cylinder Repair saves over 70% of new production and turn-around is as short as 90 days.

Image
Image

COC’s Cold Spray MLG Cylinder Repair saves over 70% of new production and turn-around is as short as 90 days.

Image
Image

Thank You

The COC F-5 Team

EXPERIENCE - OVER 5 DECADES YEARS SUPPORTING LEGACY AIRCRAFT
CUSTOMER SERVICE - OVER 50 YEARS SUPPORTING THE SAME CUSTOMERS
TRUST - ABOVE ALL, WE ALWAYS DO THE RIGHT THING

Image
COC Aerospace - Proprietary and Confidential Company Information

AS9100D