A resposta dos metais aos desafios do projeto automotivo 2
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Transcript of A resposta dos metais aos desafios do projeto automotivo 2
JUNHO/2010
CGI AND HPI “KEY POINTS”
• OUTSTANDING TENSILE STRENGTH RANGE: 300‐450 MPa.
• LOW THERMAL CONDUCTIVITY.
• LOWER VIBRATION DAMPING.
• LOWER MACHINABILITY LEVEL, HENCE HIGHER MACHINING COSTS.
•MICRO STRUCTURE STRONGLY DEPENDENT FROM DIFFERENT WALL THICKNESS INSIDE THE SAME CAST.
• HIGHER SHRINK RATE, HENCE PRESENTING TWICE THE TREND TO PROMOTE LEAKAGE ON THE CAST’S INTERNAL GALLERIES (WATER, OIL OR FUEL).
• HIGHER PRODUTION COST RELATED TO THE DRASTIC CHANGES ON FOUNDRY PROCESSES.
• PRESENTS A WIDE TENSILE STRENGTH INTERFACE WITH THE CGI’S ALLOY: 300‐370 MPa.
• OUTSTANDING THERMAL CONDUCTIVITY.
• OUTSTANDING VIBRATION DAMPING CAPACITY .
• GOOD MACHINABILITY LEVEL.
• LOW MICRO STRUCTURAL DEPENDENCE FROM DIFFERENT WALL TICKNESS INSIDE THE SAME CAST.
• PRESENTS THE SAME AND WELL KNOWN SHRINK RATE FROM TRADITIONAL GRAY IRON ALLOYS.
• REQUIRES NO RADICAL CHANGES INSIDE THE FOUNDRY PROCESSES.
• PRESENTS A GOOD THERMAL FATIGUE LEVEL COMPATIBLE WITH THE CURRENT GRAY IRON ALLOYS ( Mo BASED ).
CGI ‐ ALLOY HPI ‐ ALLOY
ABOUT HPI
HPI: THE PRIME CONCEPT
TO PROMOVE THE BEST INTERACTION RANGE AMONG 5 METALLURGICAL FUNDAMENTS IN MATERIAL ENGINEERING.
OXIDATION NUCLEATION CHEMISTRYEUTETIC
SOLIDIFICATIONEUTECTOIDIC
SOLIDIFICATION
HPI: THE MICRO ESTRUCTURETYPICALLY HYPOEUTECTIC MATRIZ: 100% PEARLITICGRAPHITE A; SIZE 4‐6BRINELL HARDNESS: < 240TENSILE STRENGTH: > 350 MPa
HPI: PROCESS ACHIEVEMENT
TO GET THE MAXIMUM CONTRIBUTION FROM EACH ONE OF THE METALLURGICAL FUNDAMENTS
EUTECTIC SOLIDIFICATION
STRATEGIC APPROACH
TO GET A CONFORTABLE RANGE BETWEEN THE STABLE AND META‐STABLE TEMPERATURES
TO KEEP THE TRADITIONAL PEARLITIZERS ALREADY WELL KNOWN BY THE MARKET
TO OPTIMIZE THE “Si / C” RATE
TO MEASURE THE CHILLING TREND ON HPI EUTECTIC PHASE
MANGANESE, SULPHUR AND SILICON INFLUENCE OVER THE EUTECTIC TEMPERATURE RANGE
( FROM S. Schwenkel and R. Döpp RESEARCH )
THERMODYNAMIC APPROACH
OM FRAS AND LOPEZ RESEARCH)
*Qd = *Qa
b.f(T ‐ Ti) / (.t)½ c.V.(Ti – T) / ∂t
TEGRATING ON THE LIMITS BETWEEN URING AND LIQUIDUS TEMPERATURE
LIMITS ( T Tp FOR TIME t = 0 ) ( T = TL FOR TIME t )
∫ ∂t (.t)½ ∫ cV(Ti‐T) / b.f.(T‐Ti)
Ln (TL – Ti) = ‐ (2b / cM½). t½ + Ln (TP – Ti)
GETTING THE MODULUS CAST
CONCLUSION
Ln (1210 30) = ‐ (2x0,09 / 5,95xMxπ½)x30½ + Ln (1435 – 30)M = 0,5348 THEORETICAL MODULUS
FROM A FAST COOLING SAMPLEMc = . M Mc = 2,60 x 0,5348 Mc = 1,39 CORRECTED
THE ACTUAL MODULUS VALUE ( MC = 1,39 ) RESULTED FROM THE POURING TEMPERATURE
PROPERTIES TRADITIONAL GRAY IRON
CGI (COMPACT GRAPHITE IRON)
AT TRANSFER RATE [W/m°K]
HPI (HIGH PERFORMANCE IRON)
HARDNESS[HB]
ENSILE STRENGHT[MPa]
ATIGUE STRENGTHMPa] : (By Rotating
Bending)
MACHINING [KM] : lling by ceramic tool400m/min speed)
CARBIDES (%)
50
200 UP TO 250
180 UP TO 270
100
12
MAX. 1%
HERMAL FATIGUE CLES] (TemperatureRange 50 – 600°C)
10,5 X 10³
50
230 UP TO 250
300 UP TO 370
180
10
MAX 2%
19 X 10³
35
207 UP TO 255
300 UP TO 450
200
6
MAX 2%
23 X 10³
PROPERTIES TRADITIONAL GRAY IRON
CGI (COMPACT GRAPHITE IRON)
MICRO STRUCTURE
HPI (HIGH PERFORMANCE IRON)
ROSITY / SHRINKAGE[TENDENCY]
DAMPING FACTOR[%]
MPACT ON ENGINE EMISSIONS
POISSON’S RATE
DENSITY (g / cm³)
Pearlite‐FerriteGraph. A, 2/5
1,0
100
We have no measured values for such item; however, being a tensilestrength function the engine emissions of our HPI alloy shall present
a very similar value related to the CIG alloy
0,26
7,20
LASTIC MODULUS[GPa] 110
1,5
100
0,26
7,20
140
3,0
50
0,26
7,20
145
Pearlite 100%Graph. A, 4/5
Pearlite 100% Graph. Compact 80%+Graph
Ductile 20%