Advancements in Hardness Testing

Interview conducted by G.P. ThomasFeb 14 2014

AZoM talks to Richard Wismer, Sales Manager of Newage Testing Instruments, about the new MT91 Microhardness Testing System.

Could you please provide a brief introduction to Newage hardness testing?

Newage is a leader in the field of hardness testing. Founded in 1954 selling portable press and read instruments, we now cover virtually every hardness testing application. Newage sells and services testers for both ferrous and non-ferrous Metals and also for Plastics and Rubbers.

Some of the highlights in Newage history include:

• Introduced the Versitron, the first and still only test surface referencing full load hardness tester in 1974
• Introduced the MT-90 the first and still only test surface referenced microhardness tester in 1981
• Introduced the Lab Boss, a truly portable Brinell Scanning Instrument in 1991
• Introduced the PB-7000, the first load cell controlled Brinell tester in 2001
• Introduced the newly redesigned AB-9000N, the direct reading Auto-Brinell Hardness tester in 2005

How does the Newage® MT91 Microhardness Testing System build on its predecessor, the MT90?

The MT-91 uses the same Newage Testing Instruments C.A.M.S.^® Computer Assisted Measurement System software as the MT-90. This software is the most intuitive and powerful case depth measurement in the marketplace.

The MT-91 updates the mechanical system to make it more reliable while retaining the test surface referencing that made the MT-90 so accurate.

New electronics incorporate more powerful controls that are also easier to maintain in the constant changing electronics and operating systems environment

The Newage® MT91 System uses Rockwell method of hardness testing. Could you give a brief overview of this method?

The Rockwell method measures the permanent depth of indentation produced by a force/load on an indenter. First, a preliminary test force (commonly referred to as preload or minor load) is applied to a sample using a diamond indenter.

This load represents the zero or reference position that breaks through the surface to reduce the effects of surface finish. After the preload, an additional load, call the major load, is applied to reach the total required test load.

This force is held for a predetermined amount of time (dwell time) to allow for elastic recovery. This major load is then released and the final position is measured against the position derived from the preload, the indentation depth variance between the preload value and major load value. This distance is then converted to a hardness number.

What are the benefits of this method compared to optical systems?

By using the Rockwell Test Method, the MT-91 offers increased speed compared to a traditional optical system in two ways; first, measurements can be made as quickly as one every 6 seconds, as compared to 15 to 25 seconds when measured optically.

Second, because the impression is not measured optically, the surface prep can be as simple as a polish with 400 grit paper. By eliminating the optical read, errors caused by the operator, uneven lighting, and poor surface finish are gone.

The MT91 test cycle is very fast – how might this benefit high-volume test applications?

The MT-91 gives the opportunity to have measurements done quicker, so that processes can be controlled closer to real time. The short cycle times of the MT-91 allows large number of samples to be measured with fewer operators.

What application areas can the MT91 Microhardness Testing System be utilised in?

While a large number of these testers are used for the measurement of such common case hardened parts as gears, bearings, and crankshafts, we have found a number of applications in the medical field, electronic components, thin metal samples, and weld affected zone testing.

How has reduced sample preparation been achieved for the MT91?

Because the measurement is done by depth of penetration using the Rockwell method, a highly polished surface is not needed. The savings in prep time can be substantial, and the cost of consumables will also be reduced.

Could you outline what is integrated into the modular Newage MT91 System?

The system is comprised of the testing system which includes the Test Head, X/Y table, video camera used for locating test points, and integral frame. The tester is controlled by the C.A.M.S.^®. software running on the latest Windows O.S. and a digital motion controller.

How does the C.A.M.S. software work and what are the primary benefits of this?

The C.A.M.S.^® Computer Assisted Measurement System controls all functions of the system. An easy, intuitive program that guides the operator through single measurements, the creation of traverses comprised of multiple measurements, and the execution of those traverses. The software also allows the operator to save all results and display or print those results in several different formats.

All data is saved in .CSV format, so transfer to other quality programs is easy. Another very important point to make about this software is that it is owned by Newage Testing Instruments and written and maintained by Newage employees. It is not a third party software package that is modified to do hardness testing. This third party software is unfortunately not uncommon in the industry, but suffers from being difficult to use and often is not supported.

What does the future hold for Newage hardness testing? Is there any new equipment on the horizon?

Newage Testing Instruments is always looking at ways to improve and expand their line of hardness testing equipment. We recently introduced a new version of our Vickers / Knoop tester for that market. Later in 2014 we will be introducing updated versions of two of our other systems.

One area of hardness testing that Newage Testing Instruments specializes in is design and build of custom testing system. We have installed stand alone system and inline system, including part handling, surface preparation, testing and sorting. We currently have several projects under construction and view this as an area of strong growth for Newage in the future.

About Richard Wismer

Richard Wismer, has been involved in the sales and service of testing equipment for over 25 years.

Previous to becoming Sales Manager of Newage Testing Instruments, he owned a Manufacturer’s Representative company in Cleveland Ohio.

He has been involved in several standards committee and currently sits on the ASTM E-18 and E-10 committee pertaining to hardness testing