Draft JTP for Hydraulic & Pneumatic Actuators National Technical Systems / Elwin Jang / December 2000

Overview of Joint Test Protocol Entire JTP Consists of 3 Parts –Part I – Material Testing –Part II – Component or Rig Testing –Part III – Flight Testing This JTP Comprises of Parts I & II

Part I – Significant Information WC/Co-Cr Selected as Primary Coating for Actuators –WC/Co Can Be Used in Less Corrosive Environment –Tribaloy T-400 as Sliding Wear Coating Primary Substrates: PH15-5 SS & 4340 Steel –Secondary Substrates: Ti Titanium & HP Steel

Part I – Significant Information (cont.) Finishes for WC/Co-Cr –Low Stress Grinding: 2-8 Ra (optimum: 2-4 Ra) –Superfinish: 4 Ra /= 90% at 0.2 micron Finish for T-400 –8-16 Ra: Unable to Make It Smoother Due to Softness & Porosity

Part I – Material Testing Includes All Tests of Landing Gear JTP –Don’t Need to Repeat Tests Which Same Coating/Substrate Combinations are Finished or Being Conducted New Tests: Functional Hydraulic, Immersion, Stripping Includes All Quality Control Tests –Excludes Tests for Same Coating/Substrate Combinations That are Finished

Part I – Tests to be Conducted Fatigue Corrosion – Neutral Salt Fog, 500 Hours Functional Hydraulic Rod/Seal – Superfinish, Side Load, Temp. Extremes, Several Vendors’ Seals Immersion –Potentiometric testing of coating in fluids (?)

Part I – Tests to be Conducted (cont.) Bond Strength Bend by Mandrel 4-Point Bend (?) Piston & Bushing Wear (?)

Part II – Recommended Tests Endurance – Withstand cyclic loads & pressure of anticipated operational life Rapid Warm Up Leakage Test: from –40 deg. F to 225 deg. F for 50 Cycles Temperature Shock: from –65 deg. F to 275 deg. F Salt Fog, MIL-STD-810, Method 509.1, 48 Hours Sand & Dust: MIL-STD-810, Method Vibration: MIL-STD-810, Method 514.2, Procedure 1A

Part II – Recommended Tests (cont.) Friction: Measure force required to pull lubricated piston rod in the assembled actuator Humidity: MIL-STD-810, Method 507.1, Procedure 1, 100% Impulse Cycling: SAE ARP 1383 Withstand 200,000 pressure impulse cycles