Tool life increased by around 80%
The developers at Walter had field-tested the new Tiger·tec® Gold WKP35G grade extensively before its launch. As expected, tests showed significant improvements in three areas in particular, which are now also confirmed under real conditions: The tools coated with WKP35G stand out thanks to significantly higher wear resistance on flank faces, lower rate of hairline crack formation and improved resistance to plastic deformation.
Intialfield test results showed a tool life that was on average 80% longer, however users in today’s market report performance increases averaging between 100% and 200%. “At peak levels, we even achieved a 300% longer tool life, not just for some particularly exotic application but with different components and materials – from structural, alloy and stainless steel to grey cast iron, compacted and spheroidal graphite,” explains Wolfgang Vötsch.
An application engineer from one of Walter customer stated: “The new grade ran far better than the previous one in compacted graphite iron.” Another engineer was also quite astonished: “The wear is so low, you cannot see anything. I was starting to wonder whether the inserts had been replaced, but no, they had not.”
The significantly increased performance of the new generation of cutting tool materials is mainly due to the unique coating properties: TiAlN, with its very high aluminium content of around 85%, stands out due to its high level of hardness and especially because of its compressive residual stress.
Still one of a kind on the global market.
The engineers at Walter developed an entirely new manufacturing process to support the deposit TiAlN in series production: ULP-CVD technology – a combination of ultra-low pressure (ULP) methods and chemical vapour deposition (CVD). So far, this process is the only one of its kind on the entire global market.
In addition to TiAlN as the main coating, the new indexable inserts also use titanium nitride (TiN): It is applied both as a link between the carbide base substrate and the TiAlN main coating and as the top layer above the main coating. It is the golden glow of TiN from which the new generation of cutting tool materials takes its name. A welcome side effect: It is much easier to identify tool wear compared to black or grey top layers.
While the hardness of the new coating leads to the previously mentioned higher wear resistance on flank faces and the improved resistance to plastic deformation, the new manufacturing method also significantly lowers the rate of hairline crack formation. Unlike the CVD coatings subjected to tensile residual stress, which have previously been commonplace across the sector, the Tiger·tec® Gold TiAlN layer is “the first coating subject to compressive residual stress manufactured with the CVD method,” according to Wolfgang Vötsch.
In addition, the new coating technology is suitable for both dry and wet machining. “Dry machining has further advantages: It is environmentally friendly, significantly lowers costs for coolants and additionally increases the tool life, because the smaller changes in temperature put much less strain on the tool.”
As one enthusiastic customer states, all in all, Tiger·tec® Gold “significantly improved both the process reliability and the tool life. In my opinion, Walter has achieved a quantum leap.”
In addition to the Tiger·tec® Gold WKP35G grade, Walter will launch further grades of the new cutting tool material generation. According to Wolfgang Vötsch, the entire range of indexable inserts for milling will also be available with the Tiger·tec® Gold WKP35G grade by early 2018.
{www.walter-tools.com Tel. 02 687 0388}