ASTM D3115 Test Method for Explosive Reactivity of Lubricants with Aerospace Alloys Under High Shear
6. Apparatus
6.1 Fluted Ball-End End Mills, two, 12.7 +/- 0.025 mm (0.500 +/- 0.001 in.) in diameter with a 6.35 +/- 0.025-mm (0.250 +/- 0.001-in.) radius tip, finished to 0.203 to 0.406 µm (8 to 16 µin.) rms.
6.2 Drill Press, capable of rotating at 1760 rpm under a 6.89-MPa (1000-psi) load.
6.3 Drill Chuck, capacity 12.7-mm (1/2-in.) end mill.
6.4 Loading Device, capable of putting a pressure of 6.89 MPa (1000 psi) on the dowel test pin.
6.5 Force Gage, 1112 N (250-lbf) force.
6.6 Drill Press Vise, capable of holding the test block in position.
6.7 Surface Texture Standards, conforming to American National Standard for Surface Texture (ANSI B46.1).
6.8 Transparent Safety Shield.
6.9 Thermocouple and Potentiometer, optional, for measuring hole-bottom temperature.
6.10 Desiccator, maintained at 50 +/- 5 % relative humidity. Water saturated with Ca(NO3)2•4H2O at 294 K (70°F) is satisfactory.
7. Materials
7.1 Blocks, of the appropriate alloy, 25.4 mm (1 in.) thick by 38 mm (1.5 in.) wide by 165 mm (6.5 in.) long. Unless otherwise specified, use metal conforming to Specification B 209, Grade 2024-T4.
7.2 Dowel Pins, of the appropriate alloy, 6.35 +/- 0.025 mm (0.250 +/- 0.001 in.) in diameter by 76 +/- 2.5 mm (3.0 +/- 0.1 in.) long and the end having a hemispherical surface with a 6.35 +/- 0.025 mm (0.250 +/- 0.01-in.) radius and an 0.203 to 0.406 µm (8 to 16-µin.) finish. Unless otherwise specified, use metal conforming to Specification B 221, Grade 2024-T4.
NOTE 1 - Both ends of each dowel pin may be so prepared and each considered a new test pin under 9.8 provided that the dimensions are maintained as required.
7.3 Acetone, reagent grade.
7.4 Test Lubricant, sufficient for at least one test series (that is, 6 mL).
8. Test Specimen
8.1 Prepare the block, as shown in Fig. 1, by drilling six holes with the 12.7 mm (0.500-in.) ball-end end mill to a depth of 12.7 mm +/- 0.254 mm (0.500 +/- 0.100 in.) measured to the tip of the hole. The hole centers shall not be less than 12.7 mm (0.500 in.) from the edge of the block or another hole. The ball end mill will create the correct surface finish in the hole when driven at 500 to 600 rpm with no lubricant.
8.1.1 If it is desired to determine the temperature attained during the test, a thermowell shall be cross-drilled to a point directly under the hole tip +/- 0.127 mm (+/- 0.005 in.) with a metal thickness between holes of 0.127 +/- 0.025 mm (0.005 +/- 0.001 in.), using a No. 80 0.343 mm (0.135 in.) drill. A bare-tipped thermocouple made from iron and constantan wires of No. 40 B & S gage (0.0114 mm (0.00315-in.) shall be inserted to full depth and tack-welded by discharging a condenser from the thermocouple to the hole bottom. An electrolytic condenser of 300 µF charged to 45 V has proved satisfactory with many metals, but some experimentation is necessary with aluminum alloys. The temperature is only a relative indication of the frictional heat generated.
8.2 Wash the specimens with acetone by dipping and airdrying and store them in a desiccator at 50 +/- 5 % relative humidity, unless the room meets this requirement and is fume-free. Do not use until at least 24 h after cleaning.
