TaeguTec Shapes Aerospace
Industry to Increase Productivity
In ancient Greek mythology, Daedalus and his son Icarus escaped King Minos’s imprisonment on Crete using feathers bonded together by wax. Tragically, Icarus, intoxicated by the ability to fly, ignored his father's warning not to fly too close to either the sun or water and fell to his death. While a myth, this story ironically justified the importance of materials and their tolerance for the ability to fly safely.
Today, planes like the Boeing 787 Dreamliner, which are made from composite materials, require cutting tools that meet the realities of shaping components that are made from a variety of metals ranging from simple-to-cut to very difficult-to-cut and shape.
“Regardless of the material used in the industry, most tier one and two customers we serve, find the challenge of machining isn't the material itself; it is productivity that turns out to be the issue,” said TaeguTec’s Aerospace Project Manager Han Seong-sik.
Titanium alloy is an example he used, “there is big demand for cutting tools as machine shops need to remove 80-90 percent of the material to meet the final dimension and tolerance criteria demanded by the aerospace industry.”
Considering the challenges posed by machining exotic materials used in aerospace, Han understands customers’ needs and looks for answers that will benefit the company's bottom line.
“Quite a few aerospace industry suppliers are also used to machining for the automotive or wind mill sector where machining speeds can reach 400 meters per minute and feed rates of 0.4 or 0.5 millimeters per revolution,” he said.
Yet, the aerospace sector is not so easy “as the metals used are super alloys such as Inconel 718 where the average machining speed is 50 m/min with a feed rate .15 mm.” This means low productivity when compared to normal alloys.
For his team, increasing productivity does not only mean recommending new generation cutting tool lines such as Chase2Feed, ChaseMold end mills or poly crystalline diamond type cutting tools, but it requires a close relationship with the customer to ensure their optimal tooling solution. TaeguTec aerospace engineers examine a company's machines, cutters and inserts as well as the speed and feed rates used in order to make recommendations that would result in the fastest material removal rate.
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Han cites one customer who received a contract to supply blisks (mono turbine disks) for aero turbine engines to a major aerospace engine manufacturer. Even though they had been producing aerospace components for some time, it was the first time this company, who wished to remain nameless, machined blisks.
He was approached by this customer and initially he believed that for an oversized component the ChaseMold line of inserts, a tough carbide grade with soft cutting edges and cutters, would be required to address the weak fixture issue.
However, after closely examining the fixtures for super alloy machining of oversized components, it turned out that a “tough carbide grade with a strong cutting edge would be more effective in compensating for the chattering that occurred during machining,” Han said.
After conducting tests at the TaeguTec Tech Center in South Korea, the aerospace team confirmed this assessment – a tough carbide grade with strong cutting edges on super alloy compensated for the chattering effect stemming from the weak fixture.
“Initially, it was taking 120 hours to produce one blisk. After adopting our solution, it took only 87 hours to complete one blisk” he said. “We also reduced the number of tools used to 198 from 248.”
The win-win situation offered the TaeguTec aerospace team a proud moment while the customer enjoyed a huge productivity increase.
Yet, this isn't the only case where the TaeguTec aerospace team improved a customer's productivity.
In the United Kingdom, the TaeguTec office was contacted by a customer that was awarded a Ministry of Defense contract to machine composite materials. The customer was experiencing burrs and delamination resulting from the hole-drilling and milling processes rendering the material useless.
After closely reviewing the demand of both the client as well as the Defense Ministry's specifications, the team hit upon a solution. They took TaeguTec’s standard ChaseMill line and installed a polycrystalline diamond chip on the end mill's cutting edge which not only eliminated burrs but solved the delamination issue as well. Again, a huge productivity increase and another satisfied customer.
The TaeguTec aerospace project team is continually seeking out opportunities to test the demanding characteristics of all materials used in this challenging field. From Malaysia to India, the team is involved in projects globally and, as Han states “the fun is solving problems and to increase productivity while reducing the client's costs.”
In India, Han had a customer who was machining Titanium 6Al-4V components, a particularly difficult to cut material; the client was experiencing a metal removal rate averaging 40-55 m/min.
“We introduced our ChaseMold series of cutters and inserts and now they're achieving a speed of 90 to 100 m/min. with a feed rate of 0.4 millimeters per revolution,” Han said.
Again, for Han and the aerospace team, this was a perfect example of productivity increase translating into significant cost reduction.
Nowadays, Han and his team are testing super alloys based on elements ranging from cobalt and iron to titanium and nickel.
“If you know the characteristics of the material, then managing it becomes easier as well,” he noted.
So, customers machining super alloys like Inconel 600, 800H or A286 can achieve higher speeds with carbide tools. On the other hand, companies that machine Inconel 718 and Rene 41 can achieve higher speeds with ceramic tools or carbide tools combined with a higher coolant pressure system.
“We are always pleased when we tell customers machining super alloys, who are used to speeds of less than 50 meters per minute, that we can increase it up to 180 meters per minute and increase tool life as well,” Han said.
Han and the TaeguTec aerospace team are always ready for the challenge of newer materials such as CFRP or other composite materials.
“CFRP while lighter, has drawbacks as well; it is difficult to shape so aluminum will still be around for a while,” said Han.
Moreover, the aluminum industry, he points out, has responded with additives such as lithium, making aluminum lighter yet denser and closer to CFRP.
TaeguTec has solutions meeting all materials used in the industry.
“If we consider Aluminum, we offer the ChaseAlu line designed for very high feed, high speed machining – over 20,000 rpm – yet it has the versatility to be used in lower powered machine set-ups,” he said. “Our tools don't produce run out in high speed, feed applications.
“We have a wide selection of tools, inserts and grades including carbide, ceramics and CBN such as the GoldRush series including the TT8080 or TT9080 coated grades; their PVD layers are the perfect match for heat resistant alloys for low to medium cutting speeds yet offer the appropriate high toughness required for these difficult to cut alloys.
“Or, our AS20 and TC430 ceramic grades adapted to high speed machining conditions for Nickel based metals which offer high hardness and high fracture toughness as well as good chemical stability,” Han said. “If we consider turning of Inconel, the KB90, our CBN grade is optimally designed with high hardness and high fracture toughness for precision, high feed turning.
“So whether it's less challenging alloys or super alloys, customers can use our tooling solutions more economically or they can adapt them to high power machining with high feed and high speed machine set ups.”
The Aerospace Project Team at TaeguTec is very confident in its range of lines available for the aerospace industry.
“Whether it's the Chase2Feed or ChaseMold on super alloys and titanium alloys, or the ChaseAlu on aluminum, we provide solutions that the industry needs,” he noted.
This article appeared in the April 2013 edition of
“International Metalworking News for Asia”
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