The high performance material titanium poses a chip removing machining challenge. Also, not all titanium is alike. Depending on whether it is pure titanium or alloyed titanium, the chip removing process behaviour differs.
For these challenges, Mikron Tool says it has developed drills perfectly tailored to the respective titanium grades, which can machine titanium safely, with higher cutting performance results, longer tool lives and excellent hole quality.
Titanium is highly demanding
Machining the unruly titanium is highly demanding. One of the reasons is the combination of its properties of high elasticity and tensile strength. Because of the high toughness, chip breaking is difficult to realise.
Due to its low thermal conductivity, heat is not dissipated from the cutting area through the chip. In addition, titanium tends to form built-up edges. This all leads to higher wear and reduces process reliability during drilling.
When drilling, the challenge is even greater
And drilling in titanium is much more challenging than milling. The viscoelastic property of titanium causes the drill to stick, and the pressure on the cutting edges increases. This usually leads to uncontrolled drill breakage. Material sticking on cutting edges and guide chamfers increase cutting forces, as a result of which the cutting edges can break out.
Moreover, the chip shape is also problematic. This is because the titanium chips tend to compact in the head area and prevent further chips from flowing in. The high temperature load on the cutting edges is an additional complicating factor.
Cool the tool
To reduce the heat in the cutting area, the cooling lubricant must reach the machining area directly. The two cooling channels with very large cross-sections carry massive amounts of coolant to the drill tip and guarantee constant cooling including lubrication of the cutting edges. At the same time, the massive coolant jet flushes the chips through the polished flutes and prevents chip jams.