• MMS Youtube
  • MMS Facebook
  • MMS Linkedin
  • MMS Twitter
8/11/2011 | 1 MINUTE READ

How Effective is MQL for Drilling Titanium/Aluminum Stacks?

Facebook Share Icon LinkedIn Share Icon Twitter Share Icon Share by EMail icon Print Icon

Titanium expert Mark Larson describes how coolant properties affect the cut. MQL might work, but water-based coolant is typically best in titanium.

Related Suppliers

A reader recently used the “Ask an Expert” feature of our Titanium Machining Zone to ask a question about MQL in titanium.

What is your opinion of the efficacy of using minimum quantity lubrication (MQL) to drill a total of 308 holes through a sandwich stack of titanium and aluminium where the hole diameters range from 2.4 mm to 15.8 mm and the stack thickness ranges from 7.5 mm to 60 mm?
Response from Mark Larson, manager of titanium process development for Makino
My first rule is that anytime you have a closed feature such as a milled pocket or drilled hole, through-tool delivery is going to give you the best result. Evacuation of chips is critical for tool life and productivity.
Other factors are these: The better the lubricity, the better the life. The better the cooling, the faster you can run.
So, if you are “cooling” only, then life may suffer. If lubricating, cooling may suffer. Higher speeds create higher heat in titanium (Watch your surface speeds on these varying diameters to control heat buildup), and only a very tiny amount of that heat goes into the titanium chip. Therefore, cooling the tool is important. The fluid with the best “heat removal” parameter is water. That means use a water-based system if possible.
If you do use an MQL system, make sure it can deliver through the tool. Even at 3:1 L:D, through-tool will help.
As for the “stacked” material condition, make sure there is no possibility for movement or slippage of the layers. Tool geometries from cutting tool companies often share geometry between aluminum and titanium. Check with the tool supplier first to make sure the cutting geometry is applicable for both materials.


  • The Case For Supplementary Fire Suppression

    Systems designed to put out fires inside machine tools can provide a level of protection that external systems such as overhead sprinklers cannot. They cost a small percentage of the investment represented by today’s CNC machines and certainly far less than repairing major damage caused by a fire. 

  • Doing Away With Coolant Disposal

    This shop installed a series of improvements that eliminated spent coolant waste.

  • Long-Lasting Coolant Reduces Costs, Downtime

    This shop provides a case in point of the substantial savings that can be realized with the proper coolant formulation. Rustlick Ultracut Pro, available from ITW Rocol North America, lasted twice as long in the sump than the shop’s previous coolant, leading to significant operating and maintenance cost savings.