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Jet Engine Part Production—An Aerospace Industry Challenge

The requirements for materials used in jet engine parts are necessarily very exacting. They must survive extremes of temperature and force, while being as light as possible and ultra-reliable. Contributed by Iscar

Image Source: Iscar

A turbojet engine can be divided simply into three sections – the compressor, the combustor and the turbine. The compressor pressurises the air flowing through the engine before it enters the combustion chamber, where the air is mixed with fuel, ignited and burnt. The compressor components are predominantly made from titanium alloys, while the combustor and turbine components are typically made of a nickel-based superalloy such as Inconel 718.

Nickel-Based Alloys

The excellent physical properties that characterise nickel-based high temperature alloys make them ideal for use in the manufacture of aerospace components.

Properties such as high yield strength and ultimate tensile strength, high fatigue strength, corrosion and oxidation resistance even at elevated temperatures enable the usage of nickel-based high temperature alloys in many applications and over a very wide temperature spectrum.

The aerospace industry accounts for about 80 percent of the nickel-based high temperature alloys used in manufacturing rotating parts of gas turbines, including  disks and blades, housing components such as turbine casing, engine mounts, and components for rocket motors and pumps.

Nickel-based high temperature alloys contain 35-75 percent Ni and 15-22 percent Cr; they constitute about 30 percent of the total material requirement in the manufacture of an aircraft engine and are also used as structural material for various components in the main engine of space shuttles.

The very same properties that make nickel-based alloys such a great choice for jet engine parts also cause substantial machining difficulties.

The cutting forces and temperature at the cutting zone are extremely high due to the high shear stresses developed and the low thermal conductivity. This, coupled with the reactivity of nickel-based high temperature alloys with the tool material, leads to galling and welding of the chips on the work piece surface and cause excessive tool wear, which can limit cutting speeds and reduce useful tool life.

All these characteristics contribute to low material removal rates and short tool life, resulting in massive machining costs.

Titanium-Based Alloys

Due to their high strength to weight ratio and excellent corrosion resistance, titanium alloy parts are ideally suited for advanced aerospace systems. Titanium-based alloys which contain 86-99.5 percent Ti and 5-8 percent Al, are immune to almost every medium to which they would be exposed in an aerospace environment.

Image Source: Iscar

Very large quantities of titanium can be found in jet engines, where titanium alloy parts make up to 25-30 percent of the weight, primarily in the compressor. The high efficiency of these engines is obtained by using titanium alloys in components such as fan blades, compressor blades, rotors, discs, hubs, and other non-rotor parts—for instance inlet guide vanes.

Titanium’s superior properties and light weight allow aeronautical engineers to design planes that can fly higher and faster, with high resistance to extreme environmental conditions. However, titanium has historically been perceived as a material which is difficult to machine due to its physical, chemical and mechanical properties.

The material’s relatively high temperature resistance and low thermal conductivity do not allow generated heat to dissipate from the cutting tool, which causes excessive tool deformation and wear. Titanium alloys retain their strength at high temperatures, resulting in relatively high plastic deformation of the cutting tool resulting in depth of cut notches. During machining, the high chemical reactivity of titanium alloys causes the chips to weld to the cutting tool, leading to built-up cutting edges and chip breakage problems.

Over the past few years, Iscar has invested many resources in research and development to resolve these obstacles and optimise the machining of nickel-based and titanium high temperature alloys, with solutions that include the creation of customised grades and implementation of high pressure coolant technologies to develop cutting tools that will handle the heat issues.

Grades

For high material removal rates, Iscar developed ceramic grades to facilitate machining nickel-based alloys at cutting speeds of 200–400m/min:

IW7—Whisker-reinforced ceramic grade, provides high hardness with excellent toughness used for roughing and semi-finishing continues operations at 8-10 times faster cutting speeds when compared with carbide grades.

IS25—Reinforced SiAlON composite grade, Excellent for machining Ni based high temperature alloys at continuous and light interrupted applications.

IS35—Reinforced SiAlON composite grade, Excellent for machining Ni based high temperature alloys at light & heavy interrupted applications.

A series of carbide grades was developed specifically to create tools for machining nickel-based and titanium alloys:

IC806—A hard submicron substrate combined with a thin TiAlN PVD coating. The unique coating procedure which involves a special post coating treatment creates a thinner and smoother coating layer providing the insert with the best characteristics suitable for machining nickel-based and titanium alloys.

IC804— Same TiAlN PVD coating on a harder submicron substrate designed especially for machining Ni based alloys used in newly designed jet engine parts that feature very high hardness (40-47 HRC).

IC20—An uncoated carbide grade which is highly recommended for machining aluminum and titanium. IC20 provides very high performance and is mostly used for continuous cut applications.

High Pressure Coolant Tools

Image Source: Iscar

Although high pressure coolant features have been in existence for a long time in the metal removal world. Today high pressure coolant tools play an increasingly significant role in the machining process, facilitating enhanced productivity and chip control especially for hard to machine materials such as titanium and nickel-based alloys. Incorporating high pressure is the key to directing coolant to exactly where it is needed in order to flush the chips away from the cut.

Iscar was one of the first cutting tool producers to respond to market needs by developing and manufacturing tools for the optimal use of high pressure coolant in lowering high temperatures and regulating chip flow, including Jetcut custom high-pressure coolant tools.

While the aerospace parts OEM/PMA sector is under constant pressure to keep costs down, the quality and life expectancy of the parts produced cannot be compromised—and this represents an enormous challenge for all involved.  Iscar’s enhanced cutting tools allow jet engine manufacturers to utilise the ideal materials for the production of high quality parts, with minimum wastage and maximum efficiency.

New Heights For Aerospace Industry

New Heights For Aerospace Industry

The challenges that the aerospace sector, in particular, presents motivates manufacturers to generate more inspired solutions to meet customer demands. Contributed by Sutton Tools

Melbourne-based Sutton Tools has never been hesitant about the expansion of its global markets. To its credit, the manufacturer has recently delivered increased productivity gains for a European aerospace customer.

Jeff Boyd, export manager of Sutton Tools said, “Our business has been built on tackling the most challenging demands for tools, and the aerospace sector is a prime example of an industry that constantly demands sophisticated solutions. However, it’s a tough market where there is a lot of competition and success is based on the ability to prove productivity gains.”

Several aerospace component producers in France had been buying a competitor’s brand, leading the Sutton Tools European office to identify an opportunity to manufacture a better performing solution and in doing so, win the business by delivering a 20 percent productivity gain for the customer.  Continual demand to lower costs through productivity is a key issue for the aviation and aerospace industries, with customers emphasising the need for reliance on tool stability so they can confidently forecast their production schedules and reduce machine down time.

“We recognised that development of specific aviation industry cutting tools is critical. These tools need a longer life and faster cycle times when working with high strength materials such as titanium and Inconel,” Mr Boyd said.

“The customer’s needs focused on solid carbide milling cutters between 12 to 20 mm that could deliver stable performance across a range of applications,” recounted Mr Boyd. The search commenced for a solution with full understanding that the demands of the industry meant that the company had to push the boundaries of its design and manufacturing technologies across its entire knowledge base of microgeometry, materials, coatings and micro-finishing of surfaces.

Pushing the Envelope To Produce Smarter Tools

The engineering team at Sutton Tools focused on the need for a smoother, high precision surface finish which would also strengthen the adhesion of the tool coating. To achieve the high finish needed, test results were compared from grinding tools using the tool maker’s traditional Anca ball-screw movement machines with an Anca linear motion tool grinder.

The team also experimented with different grinding wheel grades and grinding parameters to determine the best possible finish. After studying surface roughness of the tools, it was discovered that the output from a linear motion grinder could achieve a higher accuracy of surface finish than ball-screw machines.

To validate grinding methods, an optical 3D scanning technique was utilised to measure the surface area roughness at 100-1 magnification on the rake face and cutting edge on the tools. This 3D technique enabled the quality levels to be managed to a considerably high level of accuracy.

“The intensive engineering approach by our team produced a successful outcome for the customer by improving their productivity,” Mr Boyd stated, adding also that such a process has effectively demonstrated that Sutton possesses the capability of being a reliable aerospace industry supplier.

While Sutton Tools operates advanced manufacturing facilities in the Netherlands and India, it is the Melbourne factory that has carried out the whole evaluation process and produced these application-specific end mills for the French aerospace market.

In the past, titanium was not easy to machine. However, since this material has been adopted in many industries, the experience amassed by fabricators gives us lots of titanium machining insight. Today, titanium can be fabricated just as simply as stainless steel.

Here are some noteworthy things when machining titanium:

  1. Recommended cutting speed. This should be less than 60 m/min for roughing and three to four times that when finishing. Otherwise, thermal softening as well as chemical reaction between tool and workpiece, may occur. Feed rates are entirely dependent upon chip loads as well as other elements, but should be large enough to prevent work hardening. Follow cutting tool manufacturers’ recommendations.
  2. Titanium conducts heat very slowly. During machining operations, poor thermal conductivity traps heat in the work zone, severely compromising cutting tools. If your machine setup can handle the additional load, consider raising the feed rate to transfer more heat into the chips.
  3. High heat and stringy chips. Because of this, a copious flow of clean cutting fluid is required.
  4. Titanium is extremely tough. Use positive rake geometry. The cutting tool must be sharp and should have a tough substrate and hard coating.
  5. Filtration to 25-micron or better is critical. Increasing its concentration to at least 10 percent, and installing a high-pressure pump of 500 psi or more removes chips from the work area. Using coolant-fed cutting tools with inserts enhances chip control. Investing in a high-quality machine tool is key if you are serious about titanium.
  6. Titanium will grab end mills under heavy loads. This leads to scrapped workpieces and broken tools. Getting no-fail toolholders for your cutters, and hydraulic vises with hardened and ground jaws for clamping titanium parts, remedies the issue.
  7. Develop a sound machining procedure prior to the first cut. All of the part features should be analysed, taking special consideration of unsupported areas, tall or thin walls and difficult to reach features. Planning your moves carefully by utilising the right cutters, feeds and speeds, and generating toolpaths helps meet the above conditions.
Booming Aerospace Industry Spurs MRO Growth

Booming Aerospace Industry Spurs MRO Growth

The world wants to fly, and consumers worldwide are increasingly travelling more and enjoying low air fares offered by carriers. As we move into 2018, the dynamic aerospace sector continues to expand to cater to the global rapid growth in the travel sector. By Farah Nazurah

What is driving the demand for air travel? Higher living standards, a burgeoning middle class in emerging markets, cheaper air fares as well as tourism and travel growth are propelling the market, with year-on-year travel growth rates for the past five years averaging 6.2 percent, according to aircraft manufacturer Boeing’s market outlook on the global aircraft demand from 2017 to 2036.

International tourist arrivals grew 3.9 percent worldwide in 2016, which was faster than overall global gross domestic product (GDP) growth, according to the World Tourism Organisation. In 2016, the strongest regional growth was recorded in Asia Pacific.

Asia Awakens To Travel

The outlook for air travel demand is expected to remain strong with consumers spending more on travel and tourism, according to aircraf t manufacturer Bombardier’s market forecast for 2017 to 2036. In terms of growth rate, South Asia and Greater China are projected to be the fastest growing markets, with a compound annual growth rate (CAGR) of 5.7 percent and 4.6 percent respectively.

The economic and income growth in large emerging economies such as China and India are major drivers to the global GDP growth and air travel demand. China has fuelled the world traffic growth over the past few years and its passenger growth has increased at an average rate of more than 10 percent annually, according to Boeing.

India’s newly-emerged high-growth economy is contributing to more than 20 percent of passenger traffic growth per year in its domestic market, and is projected to become the third largest commercial aviation market by the early 2020s.

The fast-growing middle class in both countries are ready to spend more on air travel, and the middle class in both countries has risen from 80 million in 2000 to 135 million in 2016, which is an increase of nearly 70 percent.

Fast Expanding MRO Market

As air travel grows, consequently the need for aircraft maintenance, repair and overhaul (MRO) expands as well. MRO providers play an essential role in sustaining the world’s airline fleets, and assuring aircraft safety and airworthiness.

The global aircraft MRO market reached US$66 billion in 2016, and is projected to rise at a CAGR of 6.17 percent from 2018 to 2023, according to market intelligence agency Research and Markets. The ever-expanding global aircraft fleet size and market for low-cost carriers, alongside the stronger demand for technological upgrades of existing fleet, are expected to propel the global MRO market in the next five years.

The number of aircraft in service is increasing, driven by a higher penetration of commercial carriers in the world’s emerging economies and orders for new aircraft thus, steering the aircraft MRO market in an upward momentum.

Asia Pacific is witnessing a significant rise in daily air traffic, owing to the growing number of MRO facility establishments in the region. China, India, Japan, and South Korea are a few of the leading countries in the region’s commercial aviation market, and the region’s MRO market is forecast to amount to US$30.48 billion by the end of 2022, according to market research firm Research and Markets. This creates ample opportunity for MRO providers to expand in the region.

Singapore’s Substantial Role In MRO

What exact role does Singapore play in the aircraft MRO sector? The country’s aerospace industry has stringent safety and quality standards, which sees it recognised as a reliable one-stop solutions provider for aircraft maintenance and repair needs.

This includes nose-to-tail capabilities such as engine overhaul, structural and avionics systems repair, airframe maintenance, as well as aircraft modifications and conversion.

“With more than 130 aerospace companies, Singapore has the largest and most diverse concentration of aerospace companies in Asia,” informed Tan Kong Hwee, executive director of transport engineering, Singapore Economic Development Board. The country has developed a robust aerospace industry that includes manufacturing, engineering, research and development, MRO, and other aerospace-related services.

Employing over 20,000 staff, the sector has an annual output of more than US$6 billion. The nation currently holds 25 percent of Asia’s MRO market and approximately 10 percent of the global share. The reason airliners tend to choose the country for their MRO needs is because they can have all their work done in a “one-stop shop,” instead of having to get their aircraft serviced in several different locations.

Cost is an especially important factor in the aerospace industry; although MRO costs are higher in Singapore, the aircraft can be serviced faster. For example, an aircraft serviced in Singapore for 30 days as compared to 50 days elsewhere translates to cost savings for airliners, as the aircraft can generate profits for those 20 extra days of uptime.

Support Spurring Innovation

The Singapore government’s commitment to maintain a free market also enables businesses to easily operate in the country. According to the World Bank’s Doing Business 2017 report, Singapore is ranked as the world’s second-easiest country in which to do business after New Zealand.

Moreover, the country’s skilled workforce, political stability, established logistics, infrastructure and protection of intellectual property facilitates the ease for aerospace providers to set up business there.

“Government support is also crucial to the efficiency of the logistics and supply chain activities which support the MRO sector,” said Louis Leong, vice president, Asia, Hawker Pacific Asia. He also stated that the Singapore government is also heavily supporting the development of local talent in the aerospace industry through partnerships with education institutions.

Besides MRO, aerospace-related research and development activities in Singapore have grown significantly over the past few years. The nation will have to advance further in this field to maintain its edge in the industry, and continue developing Industrial Internet of Things (IIoT) technologies such as aircraft health monitoring where sensors monitor temperature, position and pressure; predictive maintenance; and the use of drones, robots and virtual reality in MRO.

An example of a joint venture leveraging on IIoT is Rolls Royce, a provider of aerospace power systems. The manufacturer partnered with Singapore Aero Engine Services Private Limited as well as the Agency for Science, Technology and Research in Singapore in September last year. The partnership saw an investment of US$45 million, which will operate a joint lab for five years to develop advanced manufacturing technologies for the aerospace industry.

“Singapore has also seen a steady increase in aerospace manufacturing activities, with some of the most complex engine and avionics parts produced in Singapore,” stated Mr Tan.

MRO environment

Planning, part tracking, and visit packaging of scheduled routine maintenance are important in the MRO environment. Image Source: Rolls Royce

Thailand’s Emerging Aerospace Industry

Thailand is seeking greater market share in Southeast Asia’s aerospace sector, and aims to duplicate the success of its automotive industry, which is the 12th largest in the world. To develop itself into a full-service aerospace hub, the country is leveraging on its strategic location, low labour costs, and expanding network of free trade agreements.

Air passenger traffic has been growing in Thailand, due to the upward trend in country’s tourism industry. The airports managed by Airports of Thailand (AOT) handled 121.7 million passengers in 2016, an increase from 109.8 million passengers in 2015, according to the leading operator at AOT. There were a total of 790,194 aircraft movements (take-offs and landings) in 2016 as compared to 727,750 in 2015.

In the next 20 years, it is expected that 42 percent of the 32,146 global aircraft deliveries will be in Asia Pacific, according to market intelligence agency Frost & Sullivan. This results from the exponential growth of passenger traffic that will increase from 60 million unique passengers in 2017 to 180 million unique passengers by the end of 2037. In Thailand, the amount of total aircraft is projected to almost triple from 314 aircraft in 2017 to 811 aircraft by 2037.

The Thai government is sparing no effort to achieve their goal to be an MRO hub. To accelerate investment, the nation has implemented the “Super- Cluster” program that allows companies to be eligible for eight-year corporate tax exemptions and an additional five-year reduction of 50 percent, provided they are in the designated cluster areas. The country also has aviation schools that offer courses for engineers, technicians and mechanics.

Thailand’s transport ministry has also commenced a development plan that started in 2017 and will last until 2031, with the plan divided into three phases. The first phase between 2017 and 2021 will see Thai Airways building a new MRO centre; the second phase will focus on the continued expansion of the centre until 2026; and the third phase will target the expansion of the nation’s aviation design and manufacturing capabilities. Moreover, the Thai government has also initiated a US$5.7 billion plan to transform its U-Tapao airport into an MRO centre.

The airport is located 140 km southeast of the nation’s capital city, Bangkok, and will start operations by 2026. The country currently has six MRO providers servicing the aerospace industry, but industry experts said it would take at least a decade to put the necessary infrastructure in place before the country can be on the same footing as Singapore’s MRO sector.

These government-led initiatives could create a US$30.8 million industry as well as 7,500 jobs, according to officials from the Thai government. Additionally, it could reduce the cost of the annual maintenance for local airlines by US$20 million over 30 years.

Big Data: Advancing Aerospace MRO

MRO providers play an essential role in sustaining the world’s airline fleets, and assuring aircraft safety and airworthiness. Image source: Rolls Royce

Big Data: Advancing Aerospace MRO

As more highly connected next-generation aircraft enter the world’s fleets in the next 20 years, MRO providers and original equipment manufacturers are adopting strategies to collect the right information from the vast amount of data gathered through IIoT technologies. The aerospace MRO sector operates on thin profit margins, and MRO providers are under continuous pressure to be as efficient as possible—big data enables providers to improve operational efficiency and minimise downtime.

“As an SME, we must also start to take advantage of Industry 4.0 technologies to improve our utilisation and productivity,” stated Soh Chee Siong, chief executive officer of JEP Precision Engineering—a manufacturer of Inconel and titanium products for the aerospace industry— at the launch of their smart factory in Singapore in November 2017.

“More so in Singapore’s context, where the labour market is tight and operating cost is increasing, we must transform the company using this technology, and create a more data-driven environment so that decisions can be made efficiently and effectively,” added Mr Soh.

All About The Data

Numerous opportunities are available in the MRO sector that leverage on big data to enable services such as predictive analytics, improved monitoring of usage patterns, or tracking and anaylsing the health of equipment in real-time. Centralising information is also essential—a central database needs to store all the vital data and link them back to the source files to ensure that all updates are automatically delivered to staff.

Planning, part tracking, and visit packaging of scheduled routine maintenance are important in the MRO environment. Thus, MRO providers need to ensure the integration of a content authoring/publishing system into an MRO data management tool which will provide significant added value. With the capability of authoring routine and non-routine job cards directly from the data collection environment, maintenance activities can be efficiently created based on established maintenance schedules and then be tracked according to the company’s needs.

In today’s advancing digital era, it is essential to create value with the information gathered through IIoT technologies, especially so for emerging economies that want to garner momentum in the aerospace MRO sector.

China Agrees To US$250B In Deals With The US

Beijing, China: US and Chinese firms have signed deals worth more than US$250 billion on the side-lines of US President Donald Trump’s state visit to Beijing; and President Xi Jinping revealed the figure after he witnessed the signing of the deals alongside President Trump.

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