The development of tailored tool coatings plays an especially key role in increasing cutting speeds, raising productivity and lowering costs for demanding gear-cutting processes. The amazing performance dimensions that can now be achieved are demonstrated in customer tests of Oerlikon Balzers’ BALINIT ALTENSA.
Modern wear protection coatings increase tool service life and, thereby, also ultimately reduce setup costs. Their strengths are, however, above all displayed in cutting applications, in which they enable significantly higher cutting speeds. Oerlikon Balzers has decisively shaped the development of TiN coatings for gear cutting tools since their first introduction in the 1980’s. “Today, more than 60 percent of all hobs worldwide, which are used first and foremost in the automotive industry, are coated with our AlCrN coating BALINIT ALCRONA PRO,” said Dr Wolfgang Kalss, Head of Marketing and Product Management Tools.
For good reason: with coatings such as these, cutting speeds go up – and costs go down. An example calculation based on test with the new BALINIT ALTENSA coating demonstrates this: if the speed of gear cutting can be increased from 200 to 300 m/min, machining time (primary and secondary times) goes down from 0.56 to 0.42 minutes per gear. This reduces machining costs by about 25 percent, based on the machine-hour rate. If one considers the overall costs of producing a gear, this represents a cost saving of about 10 percent. It thus pays to invest in new substrate materials or coatings.
BALINIT ALTENSA is the newest product from Oerlikon Balzers successful AlCrN-family to excel, above all, in terms of wear resistance, thermal shock stability and hot hardness. In light of market demand for ever increasing processing speeds, coating properties were specifically further optimized for high temperatures. “In essence we further reduced thermal conductance and improved the hot hardness of the coating by a good 20 percent,” explained Wolfgang Kalss. This produced even greater crater wear resistance, which can, in particular, occur at high service temperatures and reduce tool service lifetime.
Abrasive wear resistance was, moreover, optimized by about 35 percent, as was oxidation resistance. This reduces flank wear at moderate and high cutting speeds and extends tool service life, even with dry machining.
The bottom line is that the numerous improvements in layer development enable considerable productivity gains with longer tool lifetimes, significant performance boosts at the highest cutting speeds for all substrates (PM-HSS, MC90, carbide), as well as higher cutting speeds and feeds.
Renowned European vehicle manufacturers and suppliers have tested BALINIT ALTENSA in different applications – PM HSS hobs and carbide hobs, carbide stick blades and HSS shaper cutters. The result: not only up to 50 percent higher cutting speeds, but also significantly higher tool service life, with both wet and dry machining. “This shows that BALINIT ALTENSA sets new performance standards for gear cutting and makes it possible to achieve previously unknown tool service lifetimes, as well as a significantly improved level of process reliability at higher cutting speeds. For the user this means: more performance and reduced manufacturing costs,” summed up Wolfgang Kalss.