Owning a business of CNC machining is complicated and expensive because the productivity of any given machining process is based on every tool working as programmed. It is necessary to keep everything in tip-top shape, replacing any broken or otherwise malfunctioning tools in the system.
This process surely includes carbide end mills, which must be sharp to be fit for ideal performance. But what you do when your carbide end mill begins to dull and therefore loses a good deal of its productivity? And how can you delay that process for as long as possible?
We completely understand that in today’s competitive market, enhancing the productivity of your tools is most important. And if you can maintain well and extend the life of your cutting tools, you can reduce your costs. All cutting tool manufacturers understand this and keep looking for recent developments to extend the life of a cutting tool. Here in this article, we are going to share some insights on how you can increase the life of your carbide end mill. What trick can save your tome, cost, and life of your carbide end mill?
Prepare the Edge
Tool edge preparation, which involves removing material from a cutting tool, is critical to extending carbide end mill life as it strengthens the edge and lowers the possibility of edge chipping, which can lead to tool failure. The tool manufacturers use different methods to prepare the edges of a tool, such as a radius, and waterfall hone shapes including brush or nylon filament brush honing.
Preparing tools edges is a balancing act between hardness and toughness. When you look at a carbide end mill for heavy roughing and interrupted cuts, then get heavy edge prep with a chip breaker. But when preparing for the heavier edges, it will require more forces and that is the rival in a less rigid setup where you may have a thin-walled part because it will cause chatter.
Control the Heat
Do you know, what is the biggest factor that contributes to lessening your tool life? That is heat.
To reduce the heat generation in the cut, you need to get new carbide grades and substrates for inserts, new coatings, and chip formers.
When we cut into metal by a cutting tool, heat is produced according to the speed of the cutting tool and that has a direct correlation to tool life. As speed increases, the tool’s life goes down in the same proportion. This phenomenon is true with any material you are cutting and with any carbide end mil you are employing an insert.
There is also a way for cutting tool manufactures to improve the overall process by improving the basic tool body. If there is a consistent effort on the part of the tool manufacturer to bring more and more practicality to the process including both the tool body and the basic material it is made of. Then the heat treatment processes can be used to enhance the life of the tool.
Reducing the heat metal cutting process should be the main focus of tool manufacturers. They should work on ways of removing as much heat from the metalworking process as possible.
The heat produced by the friction of chip removal will eventually begin to degrade the cutting elements. If you can apply the CO2 directly on the cutting interface, you can also extend the life of the tool. The application of CO2 to the machining makes special tools necessary, however, these special tools also use standard inserts.
Control the chips
Another important tip to increase carbide end mill life is controlling the flow of chips during the cutting process. It will minimize tool failure. Manufacturers with two ways cutting tools are addressing this is by way of through-the-tool coolant designs and chip formers or chip breakers for specific cutting processes. Both the chip-formers and chip-breakers will help direct chips away from the cutting edges and that can extend tool life significantly. This is because of the design of chip-breakers as it will help to keep the heat in the chips only and the life of the carbide end mill will be extended.
Earlier in the market, the chip-formers were generic for all types of materials, but now there are chip-breaks of a variety of material groups such as chip-formers for finishing medium and rough turning of steel with reinforced cutting edges and positive rake angles. This helps to optimize the chip form, and how the chip is directed to keep it away from curling in front of the cutting edge and keep its cutting away from that edge.
Design the tool
Another important factor that contributes to a tool’s life is how it is designed. A tool must be able of achieving higher metal removal rates while exerting less stress on the spindle. A tool must be enabling of running in various spindle applications where rigidity and horsepower may be challenged. A cutting tool must endure the additional stress of simultaneous, multi-directional movements.
The utilization of both sides of a tool that has multiple cutting edges is the approach prefer by many manufacturers to increase the tool’s life.
A double-sided carbide end mill might have eight cutting edges, four on each side, to extend tool life. Another important factor is the negative or dovetail profile design of a tool that can decrease the tool life. An carbide end mill tool with double-sided inserts featuring a significantly positive cutting edge inclination offers a smooth and easy cut.
Another important factor to extend a tool life is a double-sided positive carbide end mill that also employs a dovetail design. A conventional positive carbide end mill sits in a pocket and the screw head is the only factor that can hold the carbide end mill in place. As when the carbide end mill is flipped over, the obtuse angle becomes a positive relief angle while in the cut.
Coat end mills
Like all type of material requires different amounts of heat to be machined, but you also can’t have too much heat because of the damage that your cutting tool might get and its impact on the cutting process. A recommended way to combat heat is to apply coatings on each tool such as you can apply CVD and PVD coatings.
CVD coatings are typically thicker than PVD coatings and protect the carbide end mil from heat. It is also good to wear resistance. Whereas it is thicker in coatings, it doesn’t adhere well to sharp edges, so with CVD coating, you have to be honed for better edge prep. On the other side, PVD coating is thinner and very easy to apply on sharp edges. If you want to get the best of both worlds, develop multi-layer coatings of materials this will makes the surface slippery and smooth so chips fly off.
By applying all the tips given above, you can surely extend your end mil life and increase the productivity of process.
