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aerospace industry l engineering

Optimal machining for resilient materials

WALTER milling tools set new

standards in the aerospace industry

Walter M3255 porcupine

milling cutter for roughing titanium

Aluminium alloys have played a crucial

role in aerospace production for a long time. New requirements and attempts to

reduce the weight of components as

much as possible has led to innovations in

aluminium machining and alloy types. The

main challenges in the sector are the large

volume of removed material, which for

many components can be up to 90 %, as

well as new, extremely light, yet robust

aluminium alloys that are difficult to machine. It is also necessary to take material

costs into consideration. Although aluminium alloys are cheaper than CFRP materials, their cost is still a major factor in calculating the cost per component.

Aluminium alloys – still in vogue d

"Until recently, many industrial experts

predicted that carbon fibre reinforced polymers (CFRP) will become ever more important for aircraft production. The advantages of these materials are clear - they

are light, yet astonishingly strong. That

makes them ideal for use in a branch of industry that needs to handle both incredible growth and increasingly strict requirements for energy consumption and

pollutant emissions," explains Dirk Masur,

Walter's aerospace component manager.

"However, CFRP materials also introduce

problems, since their machining is difficult

and expensive. The search for alternatives

brought aluminium alloys back to the

centre of attention. Current forecasts are

based on the assumption that the volume

of machined components will grow considerably until 2020."

The aerospace industry is on the rise. With revenue of

around EUR 40 billion, this branch of Germany's industry

reached its highest total in history in 2017, a 6 % increase

compared to 2016. German aircraft manufacturers have

invested 10 % of their turnover into research and

development (source: BDLI). The aerospace industry

counts among the pioneers of new materials and

machining processes. Tool manufacturers, such as

machining specialist Walter, keep in step with the

dynamism and innovativeness of this branch of industry.

To that end, Walter maintains a strong partnership with

research institutions such as the Institute for Technology

and Innovation Management at Hamburg University

of Technology. This cooperation has led to the

development of BLAXX M3255 porcupine milling cutter

for titanium-aluminium alloys. Another addition to the

product range is the M2131/M2331 ramping milling

cutter, which allows users reliable, precise and efficient

machining of aluminium alloys.

special 2020

T+T Technika a trh

Designed for high-speed cutting d

In the majority of structural components,

the large volume of removed material is

caused by the complexity of the shape. It

is typically the result of the need to create

pockets of various sizes and depths,

which must be machined directly into a

"raw" blank. The only economically viable

processing method is high-speed cutting

(HSC), where materials are milled at speeds of up to 3,300 m/min. Lower cutting

speeds lead to a build-up on the cutting

edge which makes milling tools wear

down faster until the machine eventually

overloads and stops. The total cost per

part ends up increasing as a result. In order to achieve the cutting values required

by suppliers of components in the aerospace industry, however, which are much

higher than average cutting values, it is

necessary to design special machines and

tools. Walter, a specialist in machining,

has introduced special ramping milling

cutters designed to meet these requirements: the M2131 and M2331, with the

latter being designed specifically to meet

the requirements of Makino machines

with speeds of over 30,000 rpm. The ability to choose between two sizes of indexable inserts allows users to achieve a 15

or 20 mm depth of cut - ideal for ramping

milling and pocket milling. Thanks to the

extra hard, yet smooth PVD coating, there

is nearly no build-up on the insert's cutting

edge, making the edge extremely resilient

to wear. The unique design of the insert

seat protects the insert from the high centrifugal forces created during high-speed