Not withstanding the recent reductions in fuel prices, and in anticipation of inevitable future price increases, many of the world’s major car manufacturers are reducing their engine sizes. Even though smaller engine capacities deliver the welcome benefit of lower fuel consumption, through the use of a range of technologies, not least advanced turbocharges, no loss of performance is experienced.
Indeed, many smaller capacity, economical engines now out-perform their much larger predecessors.
From the start of the 2014 season, even Formula 1 joined this trend by specifying 1.6i V6 engines which provide over 800 PS with the help of turbochargers.
Although they can be regarded as a relatively mature technology, relentless technical advancements in the area has made turbocharges an invaluable tool in the quest for ever greater fuel economy and continued high performance.
The machining and mass production of highly complex, extremely precise turbocharger components requires outstanding process reliability and high levels of productivity. A test case conducted in Germany, shows that ISCAR supports producers with innovative tools which provide economical and process-safe machining. For any common materials, e.g. 1.4849, 1.4848 or 1.4837, ISCAR offers optimal a customized tool systems. Each individual material has different machining characteristics and creates special demands for the cutting material and its coating.
Due to the continuously unstable cost of nickel (between 2005 and 2013 price fluctuations varied between 5 - 13€ per kilo), producers of turbochargers developed, and now use materials with low nickel elements. In order to react to these turbocharger industry changes, 3 independent ISCAR technology centers have been working on the development of advanced new cutting materials, designing innovative insert geometries and creating efficient new coatings. The fruits of this in-depth R&D are the newly developed S845 SNHU 1305 ANR-MM MS32 ISCAR tools, that are able to achieve up to 25% longer tool life compared to currently available tools.
For many years ISCAR engineers have investigated the machining of turbocharger components, this research was intensified in 2013. Turbine housings, rotor shafts, turbines, as well as compressor wheels, are of paramount importance in terms of ISCAR’s component focus. At ISCAR Germany, all turbocharger projects and requests, for participation in undertakings, such as turn-key projects with MTBs or producers and their suppliers, are supported by ISCAR specialists in the turbocharger field.
As a leading metal cutting tool innovator, ISCAR has developed special tooling solutions for the complex V-band machining of turbine housings. Here ISCAR provides a plunge operation with tangential inserts. This robust system is characterised by its high stability, in addition to its soft cutting geometry. Picture 2 shows such a plunging tool. The tool consists of an insert type fitting that fits into any insert pocket and hence is very user-friendly. ISCAR offers a wide product range which includes different standard geometries.
Turning proved to be the most economic machining strategy for the V-band contour as the component lends itself to this method, also no collisions occur. For this machining operation, ISCAR offers the most economic tool solution currently available; the 5 cutting-edged PENTA insert. This star-shaped insert is available in two standard sizes, depending on the depth of the V-band groove. A major advantage of the PENTA system is its broadly diversified product portfolio, which offers a large amount of various standard geometries, chipformers, and coatings, as well as solid carbide substrates which were especially developed for this particular application. Picture 3 shows a tool especially designed for interpolation turning operations. This advanced tool can be adjusted radially and axially, so that narrow tolerances of the V-band contour can be realised. ISCAR offers a customized end-users solution for contour turning by means of U-axis or radial face sliding unit, as well as for interpolation turning.
ISCAR even offers a customer-orientated, economical solution related to the bushing bore for the butterfly valve in the turbine housing. In this case, the modular drilling system with exchangeable head, - SUMOCHAM and the modular reaming system - BAYO T-REAM are ideal. As with SUMOCHAM, the BAYO T-REAM system provides exchangeable reaming heads. Designed for reaming high heat resistant cast steels, ISCAR has developed a reaming head which achieves up to 20% longer tool life when compared to currently used tools. This is largely due to the precise delivery of coolant to the cutting zone.
In 2013 ISCAR Germany GmbH intensified its activities in the area of metal cutting research focusing specifically on machining turbine housings. In addition to many other related activities, successful tests were completed in cooperation with the KSS manufacturer Blaser Swisslube at the company’s Swiss headquarters.
A customised benchmark in solid carbide drilling was performed. By means of the tool designed for each machining task and by applying an optimal coolant strategy with Blaser’s “Liquid Tool”, tool life was increased up to 1,200 holes at the customer’s premises and 2,000 holes at Blaser’s own Tech Center. In the field of face mill roughing, tool life improvements of up to 25% were achieved, when compared to the customer’s previously used tools. Even face mill finishing efficiency was increased by 45%.
