Purchase Order NNC08VA24P

MOLYBDENUM/CARBON ON WIRE CO-SPUTTER MOLYBDENUM/CARBON ON WIRE MESH [CONTACT AT GRC IS JAMES SOVEY, (216) 977-7454, JAMES.S.SOVEY@NASA.GOV] 1. CONTRACT SUMMARY: CO-SPUTTER MOLYBDENUM/CARBON COATINGS ON NON-GRIT BLASTED WIRE MESH AND GRIT BLASTED/SPOT-WELDED WIRE MESH COUPONS TO THICKNESSES IN THE 15 M TO 20 M RANGE WITHOUT CRACKING OR SPALLING OF THE COATINGS. COUPONS WILL BE MOUNTED ON A PALLET. THE CARBON IN THE COMPOSITE COATING IS TO BE 1% TO 5% BY WEIGHT (OR 7 TO 35 ATOM PERCENT), AND THE REMAINDER OF THE COATING IS MOLYBDENUM. 2.0 CONTRACT REQUIREMENTS 2.1. ONCE THE COUPONS ARE CLEANED BY NASA GRC, SUBSEQUENT CLEANING SHOULD ONLY INVOLVE INERT GAS DUSTING. THERE SHOULD BE NO ION ETCHING BEFORE THE SPUTTER DEPOSITION. (WE WANT TO SIMULATE THE ION THRUSTER COATING ENVIRONMENT AS BEST WE CAN. OBVIOUSLY THE DEPOSITION RATES ARE MUCH HIGHER THAN THAT EXPERIENCED BY THE ION THRUSTER.) COUPONS MOUNTED ON A PALLET WILL BE SPUTTERED (BY THE CONTRACTOR) IN A RF OR DC SPUTTERING SYSTEM SUCH THAT THE CARBON IN THE FILM IS 1% TO 5% BY WEIGHT (OR 7 TO 35 ATOM PERCENT), AND THE REMAINDER OF THE FILM IS MOLYBDENUM. COATING THICKNESS SHALL BE IN THE 15 M TO 20 M RANGE. 2.2. THE PALLET SHALL BE HANDLED USING CLEANED TWEEZERS OR UN-POWDERED LATEX OR NITRILE GLOVES. IT IS ANTICIPATED THE CONTRACTOR WILL NOT NEED TO REMOVE THE COUPONS FROM THE PALLET. COUPONS, MOUNTED TO A PALLET, WILL BE STORED AND SHIPPED IN A PLASTIC CONTAINER PROVIDED BY NASA GRC. 2.3. OIL FREE PUMPING SHALL BE USED. 2.4. IT IS PREFERRED THAT THE COATING SHALL BE ACCOMPLISHED WITHOUT BREAKING VACUUM. 2.5. THE CONTRACTOR SHALL DOCUMENT THE SPUTTERING SET-UP GEOMETRY, CALIBRATION DATA, PROPOSED PROCEDURES, AND COATING CONDITIONS INCLUDING NUMBER AND MAGNITUDES OF TEMPERATURE CYCLES, EXPOSURE TO ATMOSPHERE, AND ANY INCIDENTS THAT MIGHT COMPROMISE THE INTEGRITY OF THE COATING PROCESS. BEFORE STARTING THE COATING PROCESS THE CONTRACTOR SHALL SUBMIT TO GRC A LIST OF NON-PROPRIETARY PROCEDURES THAT WILL BE USED IN THE COATING PROCESS SO GRC CAN BE AWARE OF THE CONTRACTOR S APPROACH, CLEANLINESS, AND QUALITY CONTROL EFFORTS. 2.6. A LOG SHALL BE KEPT PROVIDING THE COATING TIMES, VOLTAGES, CURRENTS, VACUUM FACILITY PRESSURE, EXPOSURE TO ATMOSPHERE, AND VISUAL EVIDENCE OF FILM SPALLING DURING OR AFTER THE COATING PROCESS. 3.0 COUPON DEFINITION AND PROCESSING BY NASA GRC 3.1 THE COATING PROCESS WILL USE STAINLESS STEEL WIRE MESH COUPONS PROVIDED BY GRC. WIRE MESH IS IDENTICAL TO THAT USED IN THE NEXT ION THRUSTER AND IS DIFFUSION BONDED TO A 90 M THICK STAINLESS STEEL BACKING. 3.2 STAINLESS STEEL WIRES ARE CONFIGURED IN A 165 X 800 MESH DUTCH WEAVE. 3.3 COUPON DIMENSIONS WILL BE ABOUT 2 CM X 2 CM X 0.25 MM 3.4 THE COUPONS WILL BE MOUNTED BY GRC ON A PALLET (STAINLESS STEEL OR TITANIUM). 3.5 THE PALLET ENVELOPE WILL BE ABOUT 4 INCH X 4 INCH X 0.2 INCH. THE COUPONS WILL BE MOUNTED WITHIN A 3 INCH X 3 INCH AREA. (SUBJECT OF DISCUSSION WITH CONTRACTOR) 3.6 AT LEAST 4 COUPONS WITH NON-GRIT BLASTED WIRE MESH. (COUPONS MAY BE INTENTIONALLY SCRATCHED BY NASA GRC OR HAVE FORMING IMPERFECTIONS. THE FINAL SHAPE OF THE COUPON WILL BE AS FLAT AS POSSIBLE.) 3.7 AT LEAST 4 COUPONS THAT ARE GRIT BLASTED, CLEANED AND HAVE MULTIPLE SPOT WELDS. (COUPONS MAY BE INTENTIONALLY SCRATCHED BY NASA GRC OR HAVE FORMING IMPERFECTIONS. THE FINAL SHAPE OF THE COUPON WILL BE AS FLAT AS POSSIBLE.) 3.8 ONE COUPON WITH GRIT BLASTED WIRE MESH WILL SERVE AS A CONTROL COUPON. (WE HAVE SUCCESSFULLY COATED THIS TYPE OF SUBSTRATE TO 130 M OF MOLYBDENUM IN THE PAST.) 3.9 THE GRIT BLASTING PROCESS (DONE BY NASA GRC) USES NOMINALLY 50 M ALUMINA GRIT. THE CHARACTERISTIC DIMENSIONS OF MICROSTRUCTURES PRODUCED ON THE WIRE MESH ARE NOMINALLY 10 M. 3.10 WIRE MESH COUPONS WILL BE CLEANED (BY NASA GRC) IN ACETONE AND THEN ETHYL ALCOHOL.