Provided your specimen is flat, a simple test for evaluating it's abrasion or wear resistance is
Contoured Surface Testing
Measure abrasion resistance and other material properties of finished products of any size or shape -
flat, concave or convex.
Instead of using the word "reflector", the ultrasonic operator very often uses the term
This is defined as being an "irregularity in the test object which is suspected as being a flaw".
In reality, only after location, evaluation and diagnosis has been made, can it be determined
whether or not there is a flaw which effects the purpose of the test object. The term "discontinuity"
is therefore always used as long as it is not certain whether it concerns a flaw which means a
Detection of discontinuities
The operator then scans the test object, i.e. he moves the probe evenly to and fro across the
surface. In doing this, he observes an instrument display for any signals caused by
reflections from internal discontinuities, Fig. 2.
The shape of the sound beam plays an important part in the selection of a probe for solving a test problem. It is often sufficient to draw the acoustic axis in order to show what the solution to a test task looks like. A volumetric discontinuity (hollow space, foreign material) reflects the sound waves in different directions, Figs. 4a + 4b.
The portion of sound wave which comes back to the probe after being reflected by the discontinuity
is mainly dependent on the direction of the sound wave; i.e. it does not matter whether scanning is made with a straight-beam probe or an angle-beam probe or whether it is carried out from different surfaces on the test object, Fig. 5. If the received portion of the reflected sound wave from the probe
is sufficient then the detection of the existing volumetric discontinuity is not critical, this means that
the operator is able to detect it by scanning from different directions. A plane (two-dimensional) discontinuity (e.g. material separation, crack) reflects the ultrasonic waves mostly in a certain direction, Fig. 6.
If the reflected portion of the sound wave is not received by the probe then it is unlikely that the discontinuity will be detected. The possibilities of detection only increase when the plane
discontinuity is hit vertically by the sound beam. This applies to discontinuities which are
isolated within the test object.
Improved Rotary Platform Abraser
Taber Abrasers are durable, precision-built instruments designed to perform accelerated wear tests on a variety of specimens. These include solid materials, painted, lacquered, electro-plated surfaces, plastic-coated materials, textiles, metals, leather, rubber and linoleum.
Materials are subjected to the wear action of two abrasive wheels at a known load. This wear action results when the abrasive wheels are rotated in opposite directions by a turntable on which the specimen material is mounted. The abrading wheels travel on the material about a horizontal axis displaced tangentially from the axis of the test material which results in a sliding action. An exclusive feature of the Taber Abraser is an “X” pattern of abrasion, produced by the rotary rub-wear action of the wheels. The wear pattern formed is that of two intersecting areas or a slightly curved herringbone confi guration from the outside to the center, and from the center to the outside of the specimen. An area of 30 square centimeters is subjected to test and a complete circle on the material surface is abraded at all angles of grain or weave.
Wear Testing Paints, Inks & Chemical Coatings
Wear Testing Rubber, Plastics & Films