Overcoming Machining Productivity Challenges with Aerospace Components

Overcoming Machining Productivity Challenges with Aerospace Components

The demand for air travel is back. And so is the demand for new aircraft. The volume of production demand has reached 2019 levels much sooner than many aerospace component manufacturers anticipated. As the industry looks for ways to ramp up production, aerospace machining operations are grappling with numerous challenges to meet deliveries on time.

Skilled workers that were furloughed during the slowdown went into new industries, while veteran experts retired early. Now there’s a serious skills gap in everything from programmers to engineers to operators.

Meanwhile, supply chain shortages are causing delays for scarce materials that machine shops need to get the job done. With longer lead times and higher costs for materials, aerospace component manufacturers have little room for error. A scrapped component could interrupt production and cause havoc on a workshop’s bottom line.

Machine shops need to find new ways to manufacture complex aerospace components at volume quickly. The good news is there is a wide range of solutions available to aerospace component manufacturers that can help them reduce risk, optimize throughput and do more with less. Here are five approaches machine shops should consider to meet their productivity challenges.

1. Start With Static Parts Before Investing in Improvements for Dynamic Parts

From specialized cutting tool geometries to data-driven machining, there is a wide range of solutions available to help aerospace component manufacturers reduce risk, optimize throughput and do more with less. (Image: Sandvik Coromant)

For any operation looking to make process changes that can maximize productivity, it’s best to start with the low-hanging fruit. Dynamic, moving components like turbine discs or blisks need to have impeccable surface integrity and are more complicated to machine. Changing machining processes on these parts will need to be proved out to OEMs with more documentation, analysis and cutting samples. That can take extra time and resources.

Instead, reevaluating techniques to make static parts like casings or structural components is more efficient. For instance, reconfiguring the machining process for a fan case will not require nearly as much validation. If you can improve efficiencies on static parts first, you’ll be in a better position to make larger investments in new processes for dynamic parts later.

2. Optimize Tools and Techniques on the Machines You Already Have

While many operations are turning to new machine investments to boost throughput, it’s important not to overlook ways shops can improve productivity with the machines they already have. There is an ever-increasing variety of dedicated cutting tools for difficult materials like titanium or heat-resistant super alloys (HRSAs) that can be used to optimize machining processes.

The old way of standardizing tools — using the same tool to plow through a variety of materials and cutting operations — is not a formula for success. Aerospace components are built to withstand intense heat, which means the material will transfer heat back into the cutting tool. This can lead to premature tool failures, poor surface quality, scrapped components and more downtime.

Effectively machining these materials requires precise setup conditions, the right machining method and dedicated tool insert grades and cutting geometries. Using tools optimized for a specific material can yield dramatic gains in productivity, thanks to better chip breaking and evacuation, more predictable tool wear and better surface finish.

Using tools optimized for specific materials can yield dramatic gains in productivity, thanks to better chip evacuation, more predictable tool wear and better surface finish. (Image: Sandvik Coromant)

There are also grades and geometries available for specific cutting operations and features in aerospace components. For example, end mill geometries designed for light, radial cuts in dynamic, trochoidal tool paths in engine and frame components enable light and fast cutting action to avoid heat buildup in the tool. Using specialized tools like these will improve tool life, predictability and performance.

Another critical way to avoid heat buildup in tools is making sure your coolant solution is optimized for the application. When you’re dealing with titanium or HRSAs, use precise high-pressure coolant (at least 1,000 psi) to reach the high-heat area of the cutting zone. That means incorporating tools with precision coolant nozzles that deliver coolant to the tip of the tool. Creating a parallel hydro laminar flow with high velocity not only helps remove the heat but also assists in breaking chips. With the amount of heat generated from machining HRSAs, coolant sprayed or flooded from traditional nozzles can evaporate before it ever reaches the cutting zone. It also helps to increase the concentration of your coolant to 12 percent or more, which can improve coolant life, add more lubricity and reduce heat more effectively.

3. Get More From New 5-Axis Machine Investments

When dealing with titanium or HRSAs, use precise high-pressure coolant to reach the high-heat area of the cutting zone. Creating a parallel hydro laminar flow with high velocity not only helps remove the heat but also assists in breaking chips. (Image: Sandvik Coromant)

For operations that have invested in new equipment like five-axis machines, it’s also a great time to reevaluate their machining approach. Milling a component feature using a traditional three-axis machine, for example, might require a point milling technique with a ballnose-style cutting tool. The traditional constant back and forth and very light step-overs of this process can become incredibly time-consuming. However, with the ability to rotate the tool — or part, depending on the type of machine — around the y or x plane, you might be able to do the same operation with a conical ballnose-style or optimized square shoulder-style tool in one radial cut across the part. This can greatly increase the speed of roughing and semi-finishing operations, not only because it helps avoid lengthy setups, but also because it puts tools in an optimal position to perform more effectively.

Unfortunately, many shops that have invested in new machines continue to rely on old techniques because they don’t have the resources or time to change their process. This is where the tool provider can help with engineering support for everything from CAM to machinability trials. They can do testing on complex component features from their labs or visit on-site to help customers find the most productive process.

The tool provider can also recommend optimized tools that are specially designed for five-axis functionality in aerospace applications. For example, turning detailed features like C-style grooves in a blisk is more efficient with L-shaped inserts that get into hard-to-reach areas. These come in 90-degree or 45-degree angles and are designed specifically to work with five-axis tool paths.

4. Make Data-Driven Decisions With More Robust Digital Machining Solutions

With the high-cost and high-risk nature of aerospace components, workshops increasingly need to rely on digital solutions to ensure quality and improve productivity. Today, there is a broad range of solutions that make it possible to optimize everything from metal cutting efficiency on a single machine to throughput and maintenance across the entire production.

Running dynamic tool paths in five-axis machines takes more upfront planning to be sure the cutting operation goes smoothly. Using smart verification software, shops can model the operation and verify there won’t be a collision during machining. There are also physics-based software systems that can analyze the cutting force of your process and adjust cutting data to optimize efficiency. If you’re working a dynamic tool path on a corner, for example, the software will determine where the peaks and valleys are in the forces of your cut and make adjustments.

Machining operations can also take advantage of new sensor-equipped turning adaptors and driven tool holders to improve predictive maintenance and metal cutting efficiency. Smart tool holders can gather and transmit data via Bluetooth to a computer or tablet. Operators can now monitor temperature, vibration and rpm in real time, giving them information to optimize cutting speeds and make better decisions about proactive maintenance planning.

Using the light and fast cutting action of trochoidal milling is an effective way to avoid heat buildup and tool failure when working with HRSAs. (Image: Sandvik Coromant)

When machining deep bores, sensorized, dampened turning adaptors provide similar real-time data to improve setup times and machine utilization. For example, a digital center-height indicator lets operators set up their boring bar faster and more precisely. And during the cut, real-time data on temperature, vibration and tool load via Bluetooth can be leveraged in manned and unmanned operation to improve metal removal rates and overall productivity.

Data from these solutions can also tie into a plantwide system for overall production efficiency. Some tool providers offer advanced data analytics software that can aggregate and analyze real-time machine data and provide actionable insights for more strategic decision making. This type of software can be used by everyone from operators to production managers to optimize manufacturing processes, increase machine utilization and improve profitability.

5. Leverage the Expertise of Your Tool Provider

The final piece of advice for aerospace workshops today is to remember that you are not on your own. Like many shops, if you’re struggling to find skilled resources, leveraging a partnership with a tool provider can be an effective way to fill the gaps. The right provider can offer expert guidance in everything from workforce training and CAM support to application engineering and machining trials.

When considering new partnerships, look for tool providers who know the aerospace industry inside and out and who have the engineering background to prove out better manufacturing processes. Some providers have invested heavily in their own manufacturing environments so they can run advanced machining trials and support research and development for customers. A provider who knows the industry will also be able to offer more useful training. Look for training programs that focus on complete aerospace component solutions rather than specific tools. Your team will extract far greater value from an application-specific course that covers everything from tooling strategy to techniques to materials.

Working with a global supplier that’s committed to advancing aerospace manufacturing will give you the support and service you need to optimize your processes moving forward. They’ll have the experience and know-how to help you solve your toughest aerospace challenges.

This article was written by Bill Durow, Global Project Manager, Aerospace, Space and Defense, Sandvik Coromant. For more information, visit here .