1、 Manufacturing StandardsFord Motor Company199112 IMPREGNATION OF CASTINGS - MS4-59THERMO CURE ACRYLIC POLYESTER WET VACUUM METHODEngineering Standards & Printed copies are uncontrolled.Systems Engineering (ESSE) Page 1 of 51. SCOPE: This standard outlines an approved procedure for impregnatinggray i
2、ron, zinc aluminum, and magnesium castings, and also powderedmetal components with ESE-M4G17-B (Sealer, Thermo-Cure Acrylic Polyester- Vacuum Impregnation) utilizing a vacuum (batch immersion) method.This procedure shall be used for structurally sound castings containingonly microscopic porosity and
3、 not for castings that contain visible blowholes, cracks or other similar defects.2. MATERIALS USED:2.1 IMPREGNANT: ESE-M4G17-B (Sealer, Thermo-Cure)2.2 CATALYST: Used to control resin activity ofimpregnant.2.3 DETERGENT: Some approved sealers do not require(Optional) detergents, or are compatible w
4、ith alkalinecleaners. See manufacturers recommenda-tion. If a non-alkaline cleaner isrequired, then use M99B99A(E) NonionicSurfactant: 0.5-3% concentration with roomtemperature water. (Optional Material: Anynonyl phenol polyethylene glycol ether with9-10 moles of ethoxylation.)2.4 RUST INHIBITOR: An
5、y water soluble rust inhibitor (exceptnitrate) containing basic or strongalkaline compounds, 2% by volume withwater. Some sealers are incomparable withalkaline compounds. See manufacturersrecommendations. (Rust inhibitor recommen-ded when processing ferrous parts.)NOTE: Qualified sources for materia
6、ls not specified by an ES or Mnumber shall be provided by the impregnant supplier.3. EQUIPMENT: The equipment for the impregnation process shall consist ofthe following:3.1 VACUUM CHAMBER: Impregnation chamber may be teflon coated and becapable of maintaining 29.00 in Hg (25.0 Torr) minimum.Option -
7、 This chamber may also be a pressure vessel in which casethe chamber shall conform to ASME Code Vessel Section 8, Division1, capable of maintaining 100 psi absolute pressure and 29.88 in Hg(3 Torr) vacuum.Manufacturing StandardsFord Motor Company199112 IMPREGNATION OF CASTINGS - MS4-59THERMO CURE AC
8、RYLIC POLYESTER WET VACUUM METHODEngineering Standards & Printed copies are uncontrolled.Systems Engineering (ESSE) Page 2 of 53.2 VACUUM PUMP: Vacuum pump capable of attaining 29.00 in Hg (25.0Torr) when blanked off.3.3 PROCESSING TANKS:(1) Tank for water rinse, 23.9 C +/- 5 C (75 F +/- 5 F)(1) Tan
9、k for rinse/cure water drainage, ambient temperature, minimum10 C (55 F)(1) Tank for hot water cure, 90.6 C +/- 5 C (195 F+/- 5 F)Option: Water rinse tank can be a detergent rinse tank if required.A roller platform which will rotate the submerged basket ofcastings during the cleaning cycle or an osc
10、illating platformwasher may be used to improve cleaning efficiency.4. IMPREGNATION INFORMATION:4.1 CASTING CLEANLINESS: Casting must be clean, dry and free fromgrease, oil and corrosion preventatives to assure optimum results.4.2 SOLVENT WASH (DO NOT USE ON ALUMINUM): If iron castings have beenpress
11、ure tested with oil, it is necessary that the oil be removedfrom the porosity prior to impregnation. This may be accomplishedwith a vapor degreaser containing trichlorethylene orperchlorethylene for 30 minutes. Then bake castings in an oven at233 C - 260 C (450 F - 500 F) for 4 to 6 hours to carboni
12、ze anyresidual oil. Allow castings to cool to room temperature beforeimpregnation.4.3 AQUEOUS WASH: If castings require normal cleaning, it may beaccomplished in a parts washer utilizing cleaner and hot water 71 C- 79 C (160 F - 175 F) for 10 minutes with agitation. Remove fromwash solution and imme
13、rse castings in clean hot water for 2-5minutes. Water should be hot enough so residual heat will drive offabsorbed moisture. If baking is required to remove moisture, placecastings in an oven 116 C - 127 C (240 F - 260 F) for 45 minutes.Allow to cool before placing in sealant.CAUTION: Alkaline clean
14、ers may be incompatible with some sealers inwhich case use of a 5% nonionic surfactant is suggested. Seemanufacturers recommendations.4.4 GENERAL PRE-IMPREGNATION INFORMATION: Impregnation shall beperformed after heat treatment. Normally parts are impregnatedafter all repairs and machining operation
15、s have been completed.Impregnation may be performed on castings either before or aftersurface treatments, such as anodizing or dichromating. Ifimpregnation is performed after these treatments, the castings areto be thoroughly cleaned to assure that these treatments will notadversely affect resin per
16、formance or impede resin penetration.Manufacturing StandardsFord Motor Company199112 IMPREGNATION OF CASTINGS - MS4-59THERMO CURE ACRYLIC POLYESTER WET VACUUM METHODEngineering Standards & Printed copies are uncontrolled.Systems Engineering (ESSE) Page 3 of 5Powder metal parts shall be impregnated a
17、fter sintering and/or heattreatment and before any secondary operations such as machining orgrinding.5. GENERAL IMPREGNATION PROCEDURE:5.1 Place clean, dry castings into basket, align if necessary so thatany cavities and/or blind holes face outward to facilitate removalof excess surface sealant duri
18、ng centrifuge operation.5.2 Lower basket into vacuum chamber so that the castings arecompletely submerged in the impregnation sealant. Close cover.5.3 Start vacuum pump and attain vacuum of 29.00 Hg (25 Torr) for atime period sufficient to evacuate air from castings and sealant.Recommended cycle tim
19、e: 10 minutes. Where a vacuum of 28.5 (36Torr) is being maintained, extend the vacuum cycle to 15 to 20minutes.5.4 As the completion of the vacuum cycle, system will automaticallyrepressurize to atmospheric pressure. Open Cover.OPTION: If the impregnation chamber is a pressure vessel conformingto th
20、e provisions of Section 3.1 of this specification, then anoptional pressure cycle may be incorporated into the impregnationprocess. After the vacuum cycle has been completed and the sealanthas covered the parts, a pressure cycle of 5-10 minutes of 90 to100 psi of dry air may be applied. After comple
21、tion of the pressurecycle, the pressure in the chamber is vented to atmospherecompleting the impregnation cycle.5.5 Raise basket above sealant level and drain for 30 seconds minimum.Centrifuge for approximately 1.5 to 2 minutes to remove excessresidual surface sealant. As an alternate method, basket
22、s can berotated horizontally on rollers mounted over a drip station.5.6 RINSE WATER TANK: Immerse basket of parts into rinse water.Activate air agitator and wash for 3 minutes minimum or until partsare clean. Oscillate basket of parts up and down using overheadhoist, then drain for 30 seconds minimu
23、m. An oscillating platformwasher is recommended for most applications. As an alternatemethod, baskets can be rotated on rollers submerged in the rinsetank.OPTION: Some impregnants may require a second clear water rinsetank. In which case immerse the basket of parts into clear water ordetergent rinse
24、 solution. Using a hoist, oscillating platform, orrollers to agitate parts rapidly for at least 30 second minimum.Manufacturing StandardsFord Motor Company199112 IMPREGNATION OF CASTINGS - MS4-59THERMO CURE ACRYLIC POLYESTER WET VACUUM METHODEngineering Standards & Printed copies are uncontrolled.Sy
25、stems Engineering (ESSE) Page 4 of 55.7 RINSE/CURE WATER DRAIN TANK: Remove basket from rinse water tankand place it in the rinse/cure water drain tank allowing excesswater to drain from castings. Basket may be tipped or placed onrollers in the tank and rotated horizontally to facilitate maximumdrai
26、nage of rinse water. Parts and basket may be sprayed with cleanrinse water to remove dirty rinse water. If detergent is used inthe rinse tank solution, parts and basket should be rinsed withclean rinse water prior to placing in hot water cure tank.5.8 CURE TANK: Immerse basket of parts in hot water
27、cure tank for aminimum of 10 minutes at 90 C (195 F). Basket may be oscillatedbriefly (30 seconds) minimum) if desired. Air agitation may also beused during cycle.OPTION: After cure cycle the basket may be returned to therinse/cure water drain tank to allow the excess hot water to drainfrom the cast
28、ings.5.9 Unload basket of parts into a suitable ventilated drying table.After parts have dried, they can be transferred to the nextoperation.NOTE: Processing times may change dependent on impregnation equip-ment type, part configuration and plant location.6. SEALANT CONTROLS:6.1 Temperature of the s
29、ealant bath to be maintained at sealantmanufacturers recommended temperature.6.2 Gel time of the sealant to be maintained at sealant manufacturersrecommended time and temperature.6.3 Viscosity of the sealant to be maintained at sealant manufacturersrecommended viscosity using manufacturers recommend
30、 apparatus.6.4 Items 1, 2, and 3 should be checked twice per week and appropriaterecords maintained. Depending on sealant manufacturersrecommendation, Items 1, 2, and 3 may be required once each shift.NOTE: Some thermo-cure resins may have different gel times and ZahnCup readings. See suppliers reco
31、mmended times.6.5 Sealant tank in the vacuum method only must be aerated with dry airfor a minimum of 45 minutes a day. Alternately, dry atmospheric aircan be drawn through the resin by means of pulling a vacuum on theresin and allowing atmospheric air to come up through the resinfrom the bottom of
32、the chamber.Manufacturing StandardsFord Motor Company199112 IMPREGNATION OF CASTINGS - MS4-59THERMO CURE ACRYLIC POLYESTER WET VACUUM METHODEngineering Standards & Printed copies are uncontrolled.Systems Engineering (ESSE) Page 5 of 57. GENERAL INFORMATION:7.1 Parts may be plated, painted, and/or as
33、sembled immediately upondrying.7.2 Parts can be pressure tested immediately after curing.7.3 Impregnated parts will exhibit a fluorescent resin glow on aninternal fractured surface.7.4 APPLICABLE MILITARY SPECIFICATIONS:MIL-I-17563B Impregnants for aluminum magnesium,iron and brass alloys.MIL-I-STD-276 Military Standard - Impregnation ofporous non-ferrous metal castings.7.5 Rust inhibitor to be used in all aqueous rinse tanks whenprocessing ferrous parts.
