FORD FLTM BV 061-01-2014 ALUMINUM RESISTANCE SPOT WELDING FLAMMABILITY TEST FOR WELD THROUGH ADHESIVES AND SEALERS.pdf

1、 FORD LABORATORY TEST METHOD BV 061-01 Date Action Revisions Rev. 0 2014 04 01 Released E. Hetrick / W. Moision / K. Lazarz, NA Controlled document at www.MATS Copyright 2014, Ford Global Technologies, Inc. Page 1 of 5 ALUMINUM RESISTANCE SPOT WELDING FLAMMABILITY TEST FOR WELD THROUGH ADHESIVES AND

2、 SEALERS Application This procedure is used to determine the flammability characteristics of adhesives and sealers when exposed to a spot welding cycle as described in this test. The procedure outlined herein is specific to a given aluminum alloy + pretreatment + lubricant + heat treatment + adhesiv

3、e system from a specific supplier(s). The aluminum alloy and gauge + pretreatment + lubricant + heat treatment system employed for this flammability assessment must have already been pre-qualified using FLTM BB 117-01. Chemicals, materials, parts, and equipment referenced in this document must be us

4、ed and handled properly. Each party is responsible for determining proper use and handling in its facilities. Equipment Required Resistance Spot Welder This test shall be conducted using a Medium Frequency Direct Current (MFDC) inverter. A standard single point press type welder having a low inertia

5、 head or equivalent shall be used. Welder shall be operated in constant current mode. Welding Electrodes Two Ford standard male, ”, “hi water flow” electrode caps, with 6.4 mm face diameter and 45o truncated cone nose (Ford part number WC11A26B), as specified in WC1-002, shall be used for all tests.

6、 The electrode caps must be made from RWMA Class 2 material (ISO Type A2/X). Knife Edge Caliper Mitutoyo Absolute Digimatic Model No. CD-6”CSX, or equivalent is required to measure weld button diameter. Instrumentation A calibrated current meter and force gage is required to document weld schedules.

7、 Test Panels Test panels shall be 1.0 mm 5754-O aluminum. The supplier + pretreatment + lubricant + heat treatment material system submitted shall exactly match that pre-qualified using FLTM BB 117-01. The material shall be sheared into 5 test panels measuring 38 mm x 450 mm and 5 test panels measur

8、ing 16 mm x 450 mm. All panels shall be clean and free from burrs or ragged edges that might cause localized heating at the edges of the test panel. Test setup strips shall be sheared to 25 mm x 300 mm. FORD LABORATORY TEST METHOD BV 061-01 Copyright 2014, Ford Global Technologies, Inc. Page 2 of 5

9、Conditioning and Test Conditions All test values indicated herein are based on material conditioned in a controlled atmosphere of 23 C +/- 2 C and 50% +/- 5% relative humidity for not less than 24 hours prior to testing and tested under the same conditions unless otherwise specified. Procedure Equip

10、ment Setup The electrode caps shall be installed in the machine so that they are in precise alignment in the vertical plane and their welding faces are parallel under the electrode force requirement for the thickness of the material under test. Test Setup Procedure The following procedural details s

11、hall be followed during the test setup: (1) Dress or replace electrodes prior to commencing setup and after every 5 setup strips. Top and bottom electrode cap faces shall be dressed to clean, fresh copper at each dress interval. (2) For setup, adjustments shall be made to obtain the weld schedule sp

12、ecified in Table 1: Electrode force 2500 N Weld time 83 ms Table 1. Weld schedule for setup of button diameter (3) Using 25 mm x 300 mm test strips, make six welds on the centerline approximately 35 mm50 mm apart, as shown in Figure 1. Figure 1. 25 mm x 300 mm test strip with 6 welds at 35 mm spacin

13、g (4) Do not measure the first weld on each test strip (the “shunt weld”). (5) Measure the minimum and maximum diameter of the remaining five weld buttons using a knife-edge calipers in a destructive test as shown in Figure 2 and Figure 3. The teardown weld diameter is the average of the smallest (d

14、min) and the largest (dmax) diameter of fused material, ( 2 maxmin dd + ). The ratio between dmax and dmin is not to exceed 2:1. Note that only button / plug diameter is to be measured during setup. Partial thickness and interfacial fracture areas are not to be included in averages. Only a trained a

15、nd certified operator shall characterize and measure weld buttons. FORD LABORATORY TEST METHOD BV 061-01 Copyright 2014, Ford Global Technologies, Inc. Page 3 of 5 dmaxdminWeld buttonFigure 2. Measurement of button size Figure 3. Teardown strip with five buttons (6) Setup is achieved when the averag

16、e button diameter of the five measured welds on the strip is 5*GMT, with no single weld falling below (5*GMT 0.5 mm). Weld current shall be incremented until setup is achieved. (7) Governing metal thickness (GMT) for double panel welding is defined as the thickness of the thinnest sheet. (8) Record

17、setup button diameters as well as weld controller set points and actual delivered values of secondary current, weld time, and electrode force. Preparation of Test Panels Prepare five test panel assemblies with a 6.4 +/- 0.8 mm bead of adhesive / sealer as shown in Figure 4. Welding Test The followin

18、g procedural details shall be followed during the test: (1) Welding shall commence within 5 minutes of application of adhesive / sealer to the test panels. (2) The weld schedule specified in Table 2 shall be employed during the test, with weld controller set points and actual delivered values of sec

19、ondary current, weld time, and electrode force documented: Electrode force 2500 N Weld time 200 ms Secondary current 1.1 * setup current achieved in step (6) of “Test Setup Procedure” Hold time 0 ms Welding rate 20 welds per minute Table 2. Weld schedule for flammability test Note that these paramet

20、ers are intended to provide a severe welding condition for aluminum, comparable to the severe condition employed for steel spot weld flammability testing, as specified in BV114-01. Current is increased 10% and time 140% relative to standard aluminum schedules. Electrode force is not increased relati

21、ve to standard aluminum schedules in order to maximize resistance and expulsion. (3) During welding, the anode (+) electrode shall be in contact with the narrower (i.e. 16 mm x 450 mm) strip of material. (4) Place 17 spot welds along the center line of the test panel assembly, starting 25 mm from on

22、e end and at 25 mm spacing, as shown in Figure 5. Note that welds 1 and 2 are placed at opposite ends of the assembly in order to avoid “walk” of the top coupon during the test. Welding shall be at a rate of 20 welds per minute. (5) At the completion of the first 17 spot welds, immediately return to

23、 12.5 mm from the starting end of the panel and place 18 additional spot welds on 25 mm centers midway between the previous spot welds, as shown in Figure 5. FORD LABORATORY TEST METHOD BV 061-01 Copyright 2014, Ford Global Technologies, Inc. Page 4 of 5 (6) During welding, it is anticipated that ed

24、ge welds may occur. This condition is acceptable and any flammability response should be included in the test report. (7) All tested panels are to be documented, including any panels run beyond the requisite 5. Possible causes for the preparation of additional test panels include: (a) Incomplete adh

25、esive / sealer squeeze-out along length (b) Adhesive / sealer contamination of electrode (c) Accidental extinguishment of any flames (including that attributed to exhaust hood or cooling fans) Acceptance Requirements As the result of the above weld test procedure, the adhesive / sealer adjacent to t

26、he spot welds may ignite. If ignition occurs, the number of ignition events and the duration of burning in seconds shall be documented and evaluated against the relevant Engineering Specification. Approval requires that neither of the following occur: (1) The adhesive / sealer acts as an insulator,

27、and current cannot be passed. (2) The number of ignition events and / or their duration prior to self-extinguishment exceeds that allowed in the appropriate Materials Engineering Specification. FORD LABORATORY TEST METHOD BV 061-01 Copyright 2014, Ford Global Technologies, Inc. Page 5 of 5 11 mm38 mm1 mm1 mm16 mm 6.4 mm 0.8 mm19 mmFigure 4. Preparation of test panels X X XX X X X X X X X1 3 4 17 218 19 20 34 35212512Weld sequenceAll dimensions in mm25 2525 25 25 25 12252516 3811Figure 5. Welding sequence