The linear wear test, ASTM G, reproduces the linear reciprocating motion found in many real-world tribology mechanisms. ASTM G – Designation: G – 02 Standard Test Method for Linearly Reciprocating Ball-on-Fla. ASTM G – – Download as PDF File .pdf), Text File .txt) or read online. ASTM G –
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In this test asstm, wear is reported only as the total volume lost after a set period of sliding. The ASTM G test method uses a reciprocating sliding arrangement to simulate the type of oscillating contact that occurs between a piston ring and its mating cylinder bore surface near the top-dead-center position in the cylinder where the most severe surface contact conditions occur Figure 2.
G — 02 friction forces generated during sliding. Pin g1333 measurements may be made by removing the ball specimen holder and placing the wear scar portion under a re?
The ball holder should be rigid enough so that the periodic reversal in the sliding direction does not result in tilting or other misalignment of the contact. If the calculated contact stress exceeds the hardness of either material, there will 1g33 permanent plastic deformation and elastic conditions do not apply. Tests include evaluation of base materials, heat-treated parts, surface coatings, and lubricants. Photomicrographs of the scars should be included, if available.
ASTM G – 05() Standard Test Method for Linearly Reciprocating Ball-on-Flat Sliding Wear
If procedures other than A or B are used, the report should explicitly state so, listing the conditions which are different than those described in 8. During oscillating tests, the normal force may vary slightly about the mean value due to the dynamics of the machine.
Since t133 direction of the friction force changes rapidly during the test, traditional strip-charttype recorders may be too slow to follow these changes at high frequencies of reciprocation.
However, the replacement of the specimens in the machine to continue testing may not produce identical contact conditions to those when the test was interrupted.
Universal Mechanical Testers for Tribology Testing in the Automotive Industry
In full immersion, zstm tests, h133 bath temperature shall be measured and reported. Friction forces are recorded for both forward and backward movements of the stroke. A cycle is de? Either of two sets of testing conditions designated Procedures A and B may be used. Wear volume of the? The friction coefficient data and? Bath temperature shall be controlled to within a maximum deviation of Test Number 1 2 3 4 5 6 7 8 Friction Coefficient,?
If friction never reaches a steady value, its range of values may be reported with appropriate notations as to its behavior.
ASTM G Wear Testing | RFG PETRO SYSTEMS
To compute the sliding distance in metres or number of cycles, use the following: The wear resulting from this mode of movement may differ from that experienced by the same materials sliding continuously in only one direction unidirectional sliding even for comparable durations of contact.
A block holder is used to hold the block. The height of the specimen or mount may require adjustment to ensure that this condition is ful? This test method encompasses both unlubricated and lubricated testing procedures.
Measurement and Calculation of Wear 9. Commercial designations for materials should be given, if applicable. Wear rates for the tip and the sample are calculated from the volume of material lost. Warning—For lubricated tests in which there is minimal wear, it is possible to be misled in reading the apparent wear scar diameter of the ball tip optically because of elastic recovery.
The direction of the relative motion between sliding surfaces reverses in a periodic fashion such that the sliding occurs back and forth and in a straight line. For liquid-lubricated specimens, ultrasonic cleaning in a suitable solvent may be used. This variation is to be expected.
Asstm values given in parentheses are for information only. If a bearing ball is used, it shall be clamped tightly enough to prevent slippage during the test.
For the friction coefficient, the within-laboratory coefficient of variation was A standard ring is installed on the arbor, which 1g33 in the horizontal axis.
The test samples can be of varied shape such as cylindrical as long as there is a flat zone of a certain length in the direction of movement. Piston ring segment holder Comprehensive tribology testing plays an important role in axtm applications. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
Linear Reciprocating (ASTM G133)
If reporting grain size, indicate whether the grain size is nonuniform or duplex. This test is also applicable to addressing tribological concerns for engine valve stems and rollers, including measurement of hardness and modulus of valve material, and wear tests on the valve and cylinder head interface.
Stepper-type motors may also be used provided that the motion is smooth and uniform.
The manner in which the velocity varies with time is determined by the design of the mechanism which drives the ball or? Electronic timers can asym used to terminate the test. It has been estimated that half or more of the friction losses in internal combustion engines occur at that interface, making friction tests of those areas critical. A superscript epsilon e indicates an editorial change since the last revision or reapproval. The wear resulting from this mode of movement may differ from that experienced by the same materials sliding continuously in only one direction unidirectional sliding even for comparable durations of contact.
Summary of Test Method 4. NOTE 2—This procedure requires full-immersion lubrication.
Refer to the following which applies. Test loads and speeds are to be determined by the severity of the proposed application or purpose of the testing.