Physical Metallurgy Design alloys for aircraft engine.

◈ Introduction

When we design alloys for aircraft, we have to consider many kinds of conditions. They depend on the part of aircraft. Our team choose engine alloys for our topic and especially We choose turbine alloys. A turbine is a machine or engine which uses a stream of air, gas, water, or steam to turn a wheel and produce power. Those three facts need to be regarded for turbine alloys. Firstly, the property of turbine alloy must have high strength and high-temperature strength, because it spins very rapidly. Secondly, the cost of material need to be regarded. Thirdly, the weight of material need to be regarded, because heavy aircraft needs lots of fuel. We are going to consider those three factors.

◈ Definition.

An aircraft engine is a propulsion system for an aircraft. Aircraft engines are almost always a type of lightweight internal combustion engine.

◈ Requirement for aircraft engine

․ reliable․ lightweight․ powerful․ small and easily streamlined․ repairable․ fuel efficient

◈ Problems of materials applied aircraft engine

1) Low room temperature ductility.2) Creep resistance and fracture toughness become lower as room temperature ductility increases due to changing of microstructure. 3) Above 800℃, there is the problem of oxidation resistance.4) Shortage of datum.5) High cost to manufacture.

◈ FYI : Changing of materials applied aircraft.

1) Wood.2) Aluminum alloy.3) Titanium alloy.4) Compo-site material.

◈ Design alloys for aircraft engine.

1) Reliable 2) Lightweight3) Powerful.4) Fuel efficient to give the aircraft the range the design requires. 5) Capable of operating at sufficient altitude for the aircraft. 6) Safety.7) Environmental consideration.8) Economical consideration.

◈ Jet Engine

Google Research jet engine image

(http://www.free-online-private-pilot-ground-school.com/turbine-engines.html  )

http://video.naver.com/2008111918405323069

http://blog.naver.com/dreamline20?Redirect=Log&logNo=130005560138&vid=0

◈ Jet Engine Media player

1)Iron Alloys

1. Pure iron2. Carbon steelC, Mn, P, S, Ni, Cr, Mo

2) Aluminium Alloys

1. 99% Pure Aluminium2. Al - Cu (4.4%)3. Al - Cu (4.0%) - Mg(1-1.5%) - Si(0.5%) - Mn(0.5-1%)4. Duralumin + Mg(0.5%-1.5%)5. Al - Mn : It has good corrosion resistance.6. Al - Mn(1.2%) : It has high internal force.7. Al - Mg(2.5%)

3) Magnesium Alloys

4) Titanium Alloys

◈ Considerable Metal Element

◈Turbine - Temperature

Kim Mok-soon, High Temperature Metallic Materials, Inha, 2004

*NIMONIC alloy 75 (Ni 80.0, Cr 19.5)

*NIMONIC alloy 80A (Ni 76.0, Cr 19.5, Ti 2.4, Al 1.4)

*NIMONIC alloy 90 / NIMOLOY alloy PK37 (Ni 60.0, Cr 19.5, Co 16.5, Ti 2.5, Al 1.5)

◈ Design new turbine alloys

NIMONIC alloy 90

(93%)

Ni 60 * 0.93 55.800

Cr 19.5 * 0.93 18.135

Co 16.5 * 0.93 15.345

Ti 2.5 * 0.93 2.325

Al 1.5 * 0.93 1.395

FeC (3%)Fe 3 * 0.996 2.988

C 3 * 0.004 0.012

Mg (4%) Mg 4.000

*Jet Engine - Turbine

Kim Mok-soon, High Temperature Metallic Materials, Inha, 2004

*Turbine - Structure

Kim Mok-soon, High Temperature Metallic Materials, Inha, 2004

*Turbine - material

*Design A New Turbine Alloys For Aircraft

As We mentioned about this project, it's very hard to design new alloys, so We are going to design a new turbine alloy which is based on 93% of NIMONIC alloy 90. We choose that 7% of (FeC - Mg) alloy into the NIMONIC alloy 90. FeC is cheap and it has high strength. Mg is very light. That is why, they can cover their short points each others. Following table is a final ratio of new turbine alloy.

Conclusion

We tried to find out appropriate material of aircraft, and considered such as high strength and high-temperature strength, cost of material and the weight of material. We tried to add (FeC - Mg) alloy into the NIMONIC alloy 90. FeC is heavy but Mg is light. Mg has low hardness but FeC has high strength. In addition, both materials are cheaper than Ni (which is main material of NIMONIC alloy 90).(Ni) U$/ton 8,810 (Mg) U$/ton 3,950 ( Base metal, Minor metal http://blog.naver.com/bizdsk?Redirect=Log&logNo=40056770901)

However, our knowledge is not enough to know about everything, and it's a kind of assumption. The reason is why, it can't be used directly for real aircraft. It must be verified by correct experiment. However, We hope that this report is a new attempt of aircraft material experiment.

Thank You!!

By 1Group