1、GM DAEWOO Auto & Technology EDS Engineering, GM DAEWOO Auto & Technology Standards METHOD OF POROSITY, OIL CONTENT AND RADIAL CRUSHING STRENGTH CONTENT MEASUREMENT FOR SINTERED ALLOYS EDS-T-7162 ISSUED DATE: 1994. 04. 15 REVISED DATE: 2006. 06. 19 VERSION: 2 EDS-T-7162METHOD OF POROSITY, OIL CONTENT
2、 AND RADIAL CRUSHING STRENGTH CONTENT MEASUREMENT FOR SINTERED ALLOYS PAGE: 1/4 ISSUED DATE: 1994. 04. 15 REVISED DATE: 2006. 06. 19 VERSION: 2 GM DAEWOO Auto & Technology 1. PURPOSE This standard aims at helping test personnel perform the test in an appropriate method by describing porosity, oil co
3、ntent and radial crushing strength of sintered alloys, oil impregnated. 2. SCOPE This standard specifies a test method for determination of porosity, oil content and radial crushing strength of sintered alloys, oil impregnated (hereinafter referred to as the “test piece“). 3. DEFINITION 3.1. Porosit
4、y: Total ratio of open porosity and close porosity existing in the test piece. 3.2. Oil content: Maximum ratio of oil existing in the test piece. 3.3. Radial crushing strength constant: A quotient derived from the product, which is the difference between the outside diameter and thickness of the tes
5、t piece multiplied by the radial crushing strength, divided by the product obtained from the length of the test piece multiplied by the square of its thickness. 3.4. Radial crushing strength: When the bearing is placed between two parallel plates and undergo compression perpendicular to its longitud
6、inal axis, the load which brings about the first crack shall be defined as the radial crushing strength. 4. TEST PIECE 4.1. For the test piece, the product as it is shall be used. However, in case special regulations are specified, a test piece specified shall be used. 4.2. The test piece for the fi
7、rst approval shall be at test 3, for the routine quality control at least 1. EDS-T-7162METHOD OF POROSITY, OIL CONTENT AND RADIAL CRUSHING STRENGTH CONTENT MEASUREMENT FOR SINTERED ALLOYS PAGE: 2/4 ISSUED DATE: 1994. 04. 15 REVISED DATE: 2006. 06. 19 VERSION: 2 GM DAEWOO Auto & Technology 5. APPARAT
8、US 5.1. Soxhlet extractor: The apparatus as shown in Fig. 1 shall be used. Fig. 1. Soxhlet Extractor 5.2. Oil impregnation device: A device to serve shall be capable of reducing the internal pressure of the vessel to 30X Hg (4 Kpa) or below and maintaining the temperature of oil at 805. 5.3. Balance
9、: A balance with a sensitivity to weigh 0.01% of the mass of test piece under measurement shall be used. 5.4. Drier: A device capable of maintaining the temperature inside the furnace at 1055 shall be used. 5.5. Radial crushing strength constant tester: The testing machine for determination of radia
10、l crushing strength constant shall be a tensile testing machine specified in KS B 5521. In the cases where the parallelity of two loading plates has been modified or the tester has been overhauled, reassembled or subjected to modification of its main part or reinstallation, the tester shall be verif
11、ied for accuracy at certain intervals in proportion to the frequency of use. 6. TESTING METHOD 6.1. Testing method of porosity 6.1.1. Measure the sintered density according to the method of sintered density measurement for sintered materials(EDS-T-7114). 6.1.2. Obtain the element content of each ele
12、ment by an element analyzer. 6.1.3. Examine the density of each element to record. 6.1.4. Calculate the porosity as follows. 1001 =SPBP EDS-T-7162METHOD OF POROSITY, OIL CONTENT AND RADIAL CRUSHING STRENGTH CONTENT MEASUREMENT FOR SINTERED ALLOYS PAGE: 3/4 ISSUED DATE: 1994. 04. 15 REVISED DATE: 200
13、6. 06. 19 VERSION: 2 GM DAEWOO Auto & Technology Where, P : Porosity expressed in volume percent B : Density, oil removed SP : Actual density (SP = each element proper density) 6.2. Measuring method of oil content 6.2.1. Weigh the mass of test piece, as oil impregnated(when the mass of a test piece
14、is not more than 10g, however, gather some test piece so that their mass becomes the nearest 10g and then weigh them). 6.2.2. In order to remove the oil from the test piece (EDS-T-7114), put it into a soxhlet extractor and keep it there for 3 hours or more to extract the oil using the solvent such a
15、s petroleum benzene, petroleum ether or carbon tetrachloride. After the extraction, put the test piece into the dryer, heat it at 1055 for 30 minutes to remove the residual solvent in the test piece, cool to room temperature, and weigh again the mass of test piece. 6.2.3. Repeat extraction and dryin
16、g to remove the oil until the difference in mass between before and after drying falls within the range of 0.1%. 6.2.4. Subject the test piece having been removed of the impregnated oil to water-proof treatment specified in EDS-T-7114, and weigh it. 6.2.5. Weigh the mass in water of the water-proof
17、treated test piece mentioned above. 6.2.6. Calculate the oil content as follows. ()100=SDCBAP Where, P : Oil content expressed in volume percent A : Mass of test piece, oil impregnated(g) B : Mass of test piece, oil removed(g) C : Mass of water-proof treated test piece(g) D : Reading of the balance
18、when the mass of water-proof treated test piece is weighed in water(g) S : Specific gravity of oil at the test temperature(1)Note 1) The test temperature shall be the room temperature. 6.3. Testing method of radial crushing strength constant 6.3.1. The accuracy of reading radial crushing strength sh
19、all be 1% or finer. (However, for the radial crushing strength under 100kgf the accuracy of reading may be moderated to 1kgf.) 6.3.2. Measure the length of the test piece directly or assume half the difference between the outside and inside diameters. In the case of direct measurement, the thickness
20、 shall be the mean of two values measured on two points symmetrical about the longitudinal axis of the test piece and approximately 3X inside the respective end. The outside diameter shall be the mean of each two values measured in two directions at approximately 3X inside each end right angles to e
21、ach other. The measurement of the inside diameter for determination of thickness shall be made in the same way as mentioned above. (However, exception shall be made of the case where the inside diameter is measured only with a limit gauge. The length shall be the mean value of EDS-T-7162METHOD OF PO
22、ROSITY, OIL CONTENT AND RADIAL CRUSHING STRENGTH CONTENT MEASUREMENT FOR SINTERED ALLOYS PAGE: 4/4 ISSUED DATE: 1994. 04. 15 REVISED DATE: 2006. 06. 19 VERSION: 2 GM DAEWOO Auto & Technology measurements made on two points symmetrical about the longitudinal axis of the test piece.) 6.3.3. Measure th
23、e thickness, outside diameter and length of the test piece with appropriate measuring devices to the accuracy of 0.5% or finer. (However, for thickness of 2X or below and for outside diameter or length of 10X or below, the accuracy may be moderated to 0.01X and 0.05X , respectively.) When the thickn
24、ess is determined from the difference between the outside and inside diameters, accuracy of 0.01X shall be required of each of the diameters. 6.3.4. Place the test piece between two loading plates amply admitting the entire length of test piece and arrange that the load perpendicular to the plates s
25、hall be applied to the test piece as shown in Fig. 2. Fig. 2. Example in Case of Measuring Radial Crushing Strength Constant 6.3.5. Determine the loading speeds appropriately so that the indications of loading gradually increase for each kind of the test piece. 6.3.6. Calculate the radial crushing s
26、trength as follows. ()2TLTDPK= Where, K : Radial crushing strength constant(kg/mm2) P : Radial crushing strength(kg) D : Outside diameter of test piece(mm) T : Thickness of test piece(mm) L : Length of test piece(mm) 7. INDICATION METHOD The values of porosity, oil content and radial crushing streng
27、th shall be calculated to the second decimal place and then rounded off to the first decimal place according to KS A 0021 to be taken as the radial crushing strength constant. 8. REFERENCE EDS-T-7114 Method of sintered density measurement for sintered materials KS A 0021 Rules for rounding of numerical value KS B 5521 Tensile testing machines
