One hardness tester any material
One hardness tester – any material
Keyword: Hardness testing
The Zwick Roell Group has introduced the UK's first hardness-testing system capable of establishing the hardness of any material from rubber and plastics to metal and glass. Designed for the universality of hardness testing, the patented system determines hardness to Pr DIN ISO EN 14577-1 standard by continuously measuring the depths of indentation impressions under test loads.
The company says that the technique is superior to conventional test methods because it eliminates errors and improves repeatability by removing the necessity for any visual involvement. Recording indentations in finely spaced steps as loads are synchronously applied, the system not only determines hardnesses but also provides additional information on properties such as elastic and plastic deformation, creep and relaxation behaviour, strength,indentation modulus, case depth, etc. It can be incorporated into any Zwick materials-testing machine equipped with the company's "testXpert"digital software for automatic analysis and recording. Fitted to the machine's upper crosshead, the system consists of a hardness-measurement head containing a load cell, a high-resolution depth measurement device, and an interchangeable indenter. Various indenters are available, including Vickers pyramid, Brinell ball, Rockwell cone and steel balls of different diameters. To ensure that test loads are measured free of any friction, the indenter bears directly on the load cell. A travel sensor carried on a transducer sleeve measures co-axial movement between sleeve and indenter. The complete test routine is performed automatically, a high approach speed moderating to test speed as the sensor detects contact with the specimen. Measurement starts when contact with the specimen is detected by the load cell, the indentation zero-point being calculated online so that preselected indentation depths can be achieved with the required precision. When the test load is reached the test reverses automatically until the test load zeroes. Load and indentation curves are shown on screen in real time along with statistical values and identifying data. Suitable for control by standard, master and special programs, the universal hardness test encompasses the spectrum of all other hardness-test methods.
More information is available from: Zwick Testing Machines Ltd, Southern Avenue, Leominster, Herefordshire HR6 0QH, UK. Tel: +44 (0) 1568 615201.
