ISCAR USA's National Product Manager for Turning and Threading explains the aerospace turning application.
ISCAR's new ceramic materials IS35 and IS25 have proved very successful in many difficult-to-machine materials in aerospace turning applications. The JETCUT tool (JHP tool) is another area where ISCAR continues to improve. For finishing applications, a new chipbreaker (F3S) and a new cemented carbide grade (IC804) have been introduced to provide enhanced chip control and higher wear resistance. Finally, all companies involved in turning should understand the innovative LOGIQ4TURN tool series.
The high-temperature materials used in jet engines are designed to withstand heat and require extreme processing temperatures to plasticize the material (ie chip control) when chips are generated.
Iscar's new JHP turning tool can provide high-pressure coolant at the precise location of the cutting zone, improve cutting parameters, increase tool life and manage chips.
When using typical carbide inserts, high-temperature materials usually need to be processed at a lower surface speed and feed rate. Iscar’s new IS35 and IS25 ceramic grades are a combination of silicon nitride-based ceramics (SiAlON) with aluminum, oxygen and nitrogen. These Sialon ceramics have excellent heat resistance and mechanical strength when processing aerospace materials, and can achieve higher material removal rates during roughing operations.
In most aerospace applications, the dimensional tolerances are very small, so heat or stress cannot be introduced during finishing, as this will cause the material to move or deform. Some companies use cemented carbide inserts for low-speed precision turning, and Iscar has developed a new F3S chipbreaker with cemented carbide grade IC804. Even at small finishing depths, this type of chip breaker can maintain controllable chip formation. The hard aluminum nitride titanium coating of IC804 hard alloy grade is an excellent combination for fine turning of aerospace materials.
ISCAR's mantra is "innovation never ends", which is reflected in the recently launched very innovative and distinctive turning line/blade. The LOGIQ4TURN product line includes a new type of insert (CXMG) that has better performance than traditional turning tools, such as those using CNMG inserts. The neutral or negative inclination of traditional turning tools and corresponding insert geometries (such as CNMG) can introduce unnecessary stress and pressure in turning applications. Iscar's CXMG is a free-cutting positively positioned insert with 4 cutting edges. Another feature of the LOGIQ4TURN blade is the dovetail clamping mechanism, which can firmly and accurately fix the blade in the slot. This allows positive CXMG inserts to achieve feed rates and cutting depths that normally only negative (stronger) inserts can achieve. The innovative blade design with new materials and chip formers proved extremely successful in turning materials used in the production of aerospace components.
More information: https://www.iscarusa.com
How to select pressure control components for oxygen-enriched aerospace applications.
If it can be ignited, it can burn. In mission-critical aerospace applications, even the smallest sources of pollution can cause dangerous combustion. This threat increases in oxygen-rich environments, where a steady supply of oxygen can easily support the ignition and continuous combustion of certain materials. These risks are minimized by selecting pressure control components that are proven clean and designed with materials compatible with oxygen. This combination will ensure the safety of high-pressure oxygen equipment in applications such as astronaut breathing support and rocket engine fuel pressurization.
Oxygen is highly reactive in nature, so any component or system operating in the presence of liquid or gaseous oxygen must be verifiable clean. Careful cleaning is the basis for ensuring the safe operation of the oxygen system, which can remove foreign body debris (FOD) and combustible residues that may be the source of ignition in the equipment.
ASTM G93 (ASTM International's current cleanliness standards for equipment in oxygen-enriched environments) and Compressed Gas Association (CGA) G-4.1 (outlining the cleaning methods of oxygen service equipment) are recognized industry standards, and the basic level must meet oxygen cleaning. However, many mission-critical aerospace applications involving high-pressure oxygen and other oxidants require enhanced and verifiable cleanliness.
For these critical applications, TESCOM offers enhanced cleaning options, including IEST-STD-CC1246E, which is the industry standard for enhanced cleaning for critical cleaning applications. The standard is issued by the Institute of Environmental Science and Technology (IEST) to specify and determine the cleanliness level of products that pollute key products by focusing on pollutants that affect product performance. It also includes stainless steel, high-strength alloys, specialty metals, brass, aluminum, plastics and elastomers.
The current IEST-STD-CC1246E standard is a revised version of MIL-STD-1246, designed to extend its use beyond military applications. Unlike the MIL standard, the IEST specification defines the cleanliness level of products containing various components and fluids.
Just because the material is oxygen-purified and free of combustible residues and FOD does not mean that it cannot be ignited. Choosing the right material is as important as a thorough cleaning process. For pressure control components, it is important to consider the material's oxygen index, auto-ignition temperature, and heat of combustion.
The oxygen index is the minimum oxygen concentration required for a material to continue to burn itself after being ignited under atmospheric pressure. Materials with a high oxygen index are the first choice for oxygen service; the higher the oxygen index, the lower the propensity of the material to ignite and burn. Conversely, the lower the oxygen index, the higher the tendency of the material to ignite and burn. Soft products such as Teflon, polychlorotrifluoroethylene (PCTFE) and fluoroelastomer (FKM) are generally accepted due to their high oxygen index.
Auto-ignition temperature is the temperature at which a material ignites spontaneously in the presence of pressurized oxygen. Materials with high auto-ignition temperature are the first choice for oxygen service. Materials such as Teflon and PCTFE are preferred because of their high auto-ignition temperature.
The heat of combustion is the energy released when a material burns in oxygen. Preference is given to materials with low heat of combustion, such as Teflon, PCTFE, and Vespel SP21.
For metals, the minimum combustion pressure is critical because it is the lowest oxygen pressure at which the metal will continue to burn on its own after being ignited. Flame-retardant metals such as Monel and brass are the first choice for oxygen service. The minimum combustion pressure of stainless steel and aluminum is very low, and it is generally not recommended for use in an oxygen-rich environment, even at relatively low pressures. The materials used in the oxygen system flow—lubricants, threaded seals, and even unintended materials such as compressor oil—should not be overlooked in minimizing the risk of oxygen fires.
In addition to using only oxygen-cleaned and oxygen-compatible pressure parts in the application, another benefit is to cooperate with suitable suppliers who can provide oxygen-compatible parts and deliver parts according to cleanliness specifications.
Compared with internal cleaning processes or third-party services, suppliers with internal basic or enhanced cleaning capabilities can save time and costs significantly, which may extend delivery times by weeks or months. Many third-party cleaning services may not have the technical expertise to correctly reassemble components after cleaning, thereby increasing the risk of product failure.
Choose a supplier that can help you choose the correct pressure control solution made of oxygen compatible materials and provide internal cleaning services to minimize delivery time and costs.
About the author: Ryan Kirchner is the senior regional sales manager for TESCOM, Emerson's automation solution. You can contact him at ryan.kirchner@emerson.com.
Since the birth of the space program more than 50 years ago, Emerson has been providing pressure control for aerospace customers. Its TESCOM brand continues to provide regulators, valves, manifolds and systems in accordance with strict industry standards. TESCOM engineers and technical support teams have received training on the safe use of oxygen and oxygen system design to ensure safe operation in an oxygen-rich environment. In addition, they clean all standard products in accordance with CGA G-4.1 and ASTM G93, and provide enhanced internal cleaning services that meet IEST-STD-CC1246E 100R1 certification for critical applications. They also assemble, clean and functionally test all components to reduce the risk of operational failure. The company jointly provides:
Sandvik Coromant provides tips and advice to stores looking for the ability to add heat-resistant super alloys (HRSA).
Heat-resistant super alloys (HRSA) in aircraft engine components face extreme performance requirements. What makes them very durable under the high pressure and high temperature of the engine also makes them difficult to process. It is vital that the shop knows how to successfully install HRSA engine components (each component can cost tens of thousands of dollars) to avoid costly mistakes.
Ensuring process safety is the key to the success of the store. In order to achieve repeatability and high quality when machining HRSA aerospace engine components, the shop must follow some best practices. Although these are usually related to processing HRSA, each type of HRSA, engine components and features has its own considerations, tools, and techniques.
HRSA is difficult to process because they are heat-resistant, and processing them through shear generates heat. When a piece of steel is processed in the workshop, the falling chips will absorb heat from the processing process. In HRSA, the chips resist rather than absorb heat, sending the heat back to the tool or workpiece. The heat generated will cause the carbide of the tool to become plasticized or sintered, and the blade will break; damage the tool, or worse, damage the engine components.
In order to protect tools and workpieces, it is important that the process of processing HRSA generates as little heat as possible. One method is to use tools that cut and shear HRSA instead of pushing the material away. The other is not to remove too much material too quickly, such as burying the blade deeply in the material and plowing it over. Conversely, a series of lighter and faster cuts are more effective and generate less heat. Most computer-aided manufacturing (CAM) software packages provide this cycloid or dynamic technology to make it easier to apply in stores.
General HRSA cutting best practices apply to different material bases. For aero engines, HRSA can be divided into two basic elements with completely different cutting conditions, nickel-based and titanium-based. In most cases, when turning, use uncoated tools to process titanium because titanium is chemically reactive, especially at high temperatures. Since most coatings contain titanium as well as oxygen, nitrogen and carbon, the titanium in the coating may react with the workpiece. If this happens, the titanium in the workpiece can pull the coating off the blade through adhesion wear, or weld the material to the blade.
On the contrary, nickel-based materials usually require tool coatings. They are more difficult to machine, so the surface footage per minute (sfm) needs to be 40% to 50% slower than titanium.
Understanding how titanium and nickel HRSA bases react to other materials can reveal additional processing advantages. Although it is increasingly becoming the industry standard, some workshops may not know that it is possible (and beneficial) to use tools made of materials other than traditional cemented carbide to optimize roughing and finishing processes and increase productivity. For example, shops can use ceramics to roughen nickel materials at a higher speed. (However, do not process titanium together with ceramics. It will cause a fire that is extremely difficult to extinguish). For finishing, the workshop can use polycrystalline diamond (PCD) to process titanium and cubic boron nitride (CBN) to process nickel-based materials for high-speed processing.
HRSA produces more machining force than aluminum or steel, so in order to save a lot of setup, time and fixtures, the key is to choose the right machine for different operations.
Although the store may not be able to purchase all the new machines at once, please consider upgrading the machines with the most impact. Traditional machines, such as vertical lathes, can be used for external roughing. In some cases, the internal can be used to remove rough scales on forgings or castings. Therefore, it is wiser to invest in new machines optimized for feature-based finishing. .
The complex parts in an aero engine must be perfect. Fortunately, tool companies such as Sandvik Coromant provide standard aero engine tools and blades that can accurately machine every groove, groove and groove.
One popular machined engine component, the turbine disc, has different types of undercuts. The optimized bevel blade can accurately process every complex feature. Most discs have sharp small peaks called sealing fins. Standard sealed fin inserts have built-in gaps to carefully machine these precise features. Using sealed fin inserts, it is possible to perform a technique in which the insert rises, sweeps, and then returns in the opposite direction to avoid burrs or pushing peaks past.
If machining parts with grooves and grooves is not challenging enough, there are some factors that need to be considered for blisks. The blade geometry and depth, material, and machine all affect programming and tools. Plunge milling strategies can make the machining of narrow and deep grooves faster and more cost-effective. Some unique solid carbide end mills have specially designed geometries for cutting materials in deep and narrow grooves. Solid carbide end mills with a deeper processing range can always finish machining these geometric shapes.
The valve core, combustion chamber and shaft are common engine components. When shops purchase tools to process these components, they should look for certain product portfolio features that can improve process safety. Optimized materials can improve reliability, wear resistance, increase machining accuracy, and extend tool and blade life. Choosing a tool grade is particularly important for improving process safety; no one wants to scrap a component because the insertion fails during the finishing process. The optimized geometry is sharp and can withstand high edge pressures, and damping tools can improve stability, process safety and component quality.
Each optimized tool has its own machining technology, so it is important to cooperate with experts who can teach them. Some tool suppliers, such as Sandvik Coromant, have a dedicated engineering team to support the workshop and its aerospace projects, visit the workshop and share the best methods of handling materials, features and components, as well as make machine tool recommendations, select tools, and complete CAM programming and help fix.
Some suppliers also provide in-house machining, which is very suitable for small shops with a small number of machines but great development ambitions. They can send a new HRSA material that they are not familiar with to the supplier's machining laboratory, which can conduct experiments and recommend the best tools, techniques, and cutting data. For example, Sandvik Coromant has a training center and a processing application and development center in Mayban, North Carolina, near Raleigh-Durham, dedicated to customer testing and education.
When looking for an expert, choose an expert who offers a comprehensive aerospace product portfolio. This ensures quick access to tools and techniques specific to their needs and operations, from roughing to finishing, or from complete components to specific features.
With the advancement of aerospace machining research and development (R&D) work and the emergence of more optimization tools, new best practices and technologies will emerge to provide more projects for workshops of all abilities and sizes.
Processing aerospace engine components is not a panacea. Have the opportunity to carefully consider every detail, from basic materials to components, features, processes and individual tools. Every opportunity includes decisions that can improve process safety, increase workshop productivity, and the quality of engine components it can provide.
About the author: Bill Durow is the manager of Sandvik Coromant's Office of Aerospace, Aerospace and Defense Global Programs. His contact information is contact.coromant.us@sandvik.com.
Our ability depends on our core values and commitment to quality.
We manufacture the project-specific machine tools you need. In addition to CNC vertical machining centers and lathes, Campro's comprehensive product line also includes large turning centers, double-column machining centers above 5m, horizontal machining centers, five-axis machining centers, etc. Guided by customer needs, each machine tool is uniquely customized and produced to meet customer requirements.
Campro's corporate culture is based on its philosophy, including five core values: quality first, service first, integrity, professional team and innovative technology. These values constitute our vision and serve as the highest guiding principle of our company's management.
Compro R&D employees have more than 30 years of experience in machine tool research and development. 5% of our annual turnover is used to enhance our independent research and development capabilities and to continuously improve the accuracy and functions of our CNC machine tools. Whether it is a 2-axis turning center or a complex 5-axis machining unit, we can customize it according to customer needs.
We can analyze tool wear or tool chatter data and send them directly to the central monitor or send an alert message to the manager. For customers who are just starting Industry 4.0, we can help build a visual factory management system. For customers looking for more functions, we can help build a machine-flexible production system to digitally manage the entire factory.
Our machines are inspected throughout the production process, and our employees have undergone rigorous training to comply with the ISO-certified service process.
Campro implements strict inspection and supervision of all materials provided in the supply chain. The incoming material inspection station uses high-precision testing equipment for 100% quality control; all defective and unqualified materials are returned. We carry out strict inspections on dimensional tolerances, geometric accuracy, hardness, surface treatment and other aspects in accordance with the standards specified in the design drawings.
From surface scraping to assembly, all finished products meet the VDI3441 inspection standard to ensure the best processing performance. The 6 points of our 100% quality commitment include:
These steps are in addition to checking: machine positioning accuracy, 2-axis synchronous motion compensation, spindle vibration and cutting parameters.
All machine sales, after-sales parts and service support for American customers are handled by Campro USA's office in Bethlehem, Pennsylvania. We welcome customers to our office to watch our machine demonstration or contact our team via Zoom phone.
Learn more at https://www.camppro-usa.com
Sensors and software intelligence capture key ingot quality throughout the melting process.
Commercial air travel is safer than ever. But mechanical failures can and still occur. Flight UA 328 left Denver, Colorado on February 20, 2021, and suffered a catastrophic engine failure four minutes after the flight. Fortunately, the plane returned to the airport and landed safely. Although the Federal Aviation Administration (FAA) continues to improve safety regulations, there is still much work to be done to prevent serious engine failures.
Improvements can be made at the beginning of manufacturing in the primary metal processing process. The material must be able to withstand the intense stresses and extreme temperatures experienced by the components, such as turbine disks holding turbine blades together while rotating at >10,000rpm and temperatures up to 1,700°C. As demonstrated by the UA 328 flight, the fan blades are also easily affected. The National Transportation Safety Board (NTSB) determined that the cause was fan blade failure-two fan blades fractured due to metal fatigue, which is usually the result of macroscopic and microscopic discontinuities in primary metal processing.
Today’s manufacturing process will not produce tomorrow’s aircraft engine components. Meeting these standards requires a revolution in the field of parts manufacturing, where impeccable craftsmanship and precision equipment give people confidence in the material's ability to achieve the best performance.
Ampere Scientific and Consarc Corp. teamed up to apply sensors and software intelligence to revolutionize part manufacturing. Their current task is to detect conditions that may cause defects in key engine components during the vacuum arc remelting (VAR) process. They will use this technology to predict the conditions that cause defects and prevent them from occurring.
VAR furnaces remelt and refine special alloys, which can be made into key aero engine parts for commercial and military aircraft. Current VAR furnaces rely on electrical signals for process control and ingot quality evaluation, rather than direct evaluation and real-time visualization of growing ingots.
Ampere Scientific is determined to change this situation with its VARmetric arc positioning sensing technology, which provides a view of the melting process. VARmetric combines advanced electromagnetic field sensing with Consarc's VAR furnace measurement to capture, record and display furnace operating characteristics that were previously undetectable during the melting process. It uses Consarc controls to monitor the furnace current, voltage, vacuum, load cell, plunger position/speed, and electromagnetic stirring. Then, VARmetric integrates the magnetic field measurements at multiple locations throughout the VAR to image the arc position inside the VAR.
The result is a real-time data display:
This data can be used by operators when producing ingots and can be used as part of the chain of custody record for any qualified alloy ingots. As part of the digital twin, this information can calculate the probability of solidification defects during operation. This gives metal producers, engine original equipment manufacturers (OEMs) and regulatory agencies more confidence that the materials they use are consistent in production and can withstand the harsh environments they expect to face in extreme environments.
With such guidance, solidification defects will be reduced and confidence in the quality of the ingot will increase. Higher-quality ingots produce higher-quality components, helping the next generation of aircraft to be lighter, faster, stronger, and safer.
About the author: Paul E. King is the President and CEO of Ampere Scientific. You can contact them at paul@amperescientific.com. Andrew J. Elliott is the Vice President of Technology at Consarc Corp. and you can contact him at aelliott@consarc.com.