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Hardness Testing: Quality and Process Control—Quick and Easy

It is said that the heart of the automobile is the motor. However, without the drive train, it is unable to move. Clutch, gearbox, drive shaft—all important components that deserve the same attention in development and manufacturing processes as the motor components. To be able to quickly and easily verify the quality and manufacturing process, the automotive industry uses hardness testing. For this, a tier one supplier in the automotive industry has put their complete trust in a hardness testing machine from ZwickRoell.

Case hardening of components

After soft turning and machining, shafts and gears of the drive train are heat-treated in the pusher furnace. The shafts are hardened and tempered and the gears are case hardened. When case hardening components, the material is first enriched with carbon in the surface layer and then hardened. This increases the surface hardness of the component,which results in increased wear and compression resistance, and the endurance limit is enhanced. The core of the component remains tough with relatively high strength and is therefore unbreakable under impact. These properties are of vital significance in the area of drive technology. The tempering process is carried out following the hardening process. The hardening and tempering is intended to slightly reduce the hardness and substantially improve the yield point (toughness).

For quick and easy quality and process control, the hardness of one component from the batch must be tested immediately after the heat treatment. Depending on the production line, the component variation is very high.A wide variety of geometries and sizes are tested. The large number of employees who perform the hardness test, make easy operation of the hardness tester a requirement. In addition, the process speed must be maintained. To accomplish this, while at the same time minimizing operator influence, the highest possible level of automation is desirable.A high documentation standard is also required. All data must be assigned to the correct batch and automatically saved.

Rockwell single measurement

All production lines encounter a lack of space, which is why the hardness testing machine has to be compact and not take up very much room. These requirements are met by the DuraJet. It does not occupy a lot of space in the hardening plant and with the high-precision test unit, a wide variety of components can be clamped and tested. With the rapid Rockwell single measurement, the surface hardness can be checked directly at the production line. Due to the customized database connection, the user only has to scan the barcode supplied with the component and the test can be started. All test related data is already set up and the result is exported back to the QA system without operator influence. This way none of the data is lost and seamless data management is ensured.