The Characterization of High Temperature Electronics for Future Aircraft Engine Digital Electronic Control Systems

2014 ◽  
Vol 2014 (DPC) ◽  
pp. 001818-001850 ◽  
Author(s):  
Glenn G. Daves

The long-term trend in automobiles has been increasing electronics content over time. This trend is expected to continue and drives diverse functional, form factor, and reliability requirements. These requirements, in turn, are leading to changes in the package types selected and the performance specifications of the packages used for automotive electronics. Several examples will be given. This abstract covers the development of a distributed high temperature electronics demonstrator for integration with sensor elements to provide digital outputs that can be used by the FADEC (Full Authority Digital Electronic Control) system or the EHMS (Engine Health Monitoring System) on an aircraft engine. This distributed electronics demonstrator eliminates the need for the FADEC or EHMS to process the sensor signal, which will assist in making the overall system more accurate and efficient in processing only digital signals. This will offer weight savings in cables, harnesses and connector pin reduction. The design concept was to take the output from several on-engine sensors, carry out the signal conditioning, multiplexing, analogue to digital conversion and data transmission through a serial data bus. The unit has to meet the environmental requirements of DO-160 with the need to operate at 200°C, with short term operation at temperatures up to 250°C. The work undertaken has been to design an ASIC based on 1.0 μm Silicon on Insulator (SOI) device technology incorporating sensor signal conditioning electronics for sensors including resistance temperature probes, strain gauges, thermocouples, torque and frequency inputs. The ASIC contains analogue multiplexers, temperature stable voltage band-gap reference and bias circuits, ADC, BIST, core logic, DIN inputs and two parallel ARINC 429 serial databuses. The ASIC was tested and showed to be functional up to a maximum temperature of 275°C. The ASIC has been integrated with other high temperature components including voltage regulators, a crystal oscillator, precision resistors, silicon capacitors within a hermetic hybrid package. The hybrid circuit has been assembled within a stainless steel enclosure with high temperature connectors. The high temperature electronics demonstrator has been demonstrated operating from −40°C to +250°C. This work has been carried out under the EU Clean Sky HIGHTECS project with the Project being led by Turbomeca (Fr) and carried out by GE Aviation Systems (UK), GE Research – Munich (D) and Oxford University (UK).


Author(s):  
M. Larsen ◽  
R. G. Rowe ◽  
D. W. Skelly

The thrust to weight ratio of an aircraft engine is limited by the density and elevated temperature performance of high temperature structural materials. Many material systems are currently under investigation as potential next generation engine materials. Microlaminate composites consisting of alternating layers of a ductile refractory metal for toughening and a high temperature intermetallic compound for elevated temperature strength have applicability in aircraft engine turbines. The lamellar thickness of such a composite must be small because the intrinsic defect size, a crack across the intermetallic layer, will be controlled by the intermetallic layer thickness. The microstructural characterization of a Cr2Nb-Nb(Cr) microlaminate composite produced by Magnetron® sputtering was carried out by cross-sectional TEM. Both the as-deposited composite and one heat treated at 1200°C for two hours were examined.Figure 1 shows a micrograph of the as-deposited composite. The metal and intermetallic layers are 2um thick. The metal layer has a composition in atomic percent of 95% Nb and 5% Cr.


Author(s):  
X.D. Zhang ◽  
J.M.K. Wiezorek ◽  
D.J. Evanst ◽  
H.L. Fraser

A two phase alpha-beta titanium alloy, Ti-6Al-2Mo-2Cr-2Sn-2Zr-0.2Si (Ti-6-22-22S), has recently been reconsidered as a high temperature material for aircraft engine applications. This alloy exhibits specific strength and fracture toughness superior to those of Ti-6A1-4V. However, similar to other alpha-beta titanium alloys, microstructural stability is one of the major concerns regarding industrial application of Ti-6-22-22S, since changes of the microstructure during long term high temperature exposure significantly affect the performance of components. Two types of precipitates have been observed in Ti-6-22-22S alloys, namely silicides and alpha 2-Ti3Al. The presence of intermetallic precipitates, such as alpha 2-Ti3Al, in the parent alpha matrix has been reported to result in brittle behaviour of the alpha-beta alloys due to the formation of intense planar slip bands. The present paper presents results of the characterization of intermetallic alpha2-Ti3Al precipitates in the alpha phase by methods of scanning and transmission electron microscopy (SEM and TEM respectively).


2014 ◽  
Vol 2014 (HITEC) ◽  
pp. 000285-000290 ◽  
Author(s):  
S T Riches ◽  
C Warn ◽  
K Cannon ◽  
G Rickard ◽  
L Stoica ◽  
...  

This paper covers the development of a distributed high temperature electronics demonstrator for integration with sensor elements to provide digital outputs that can be used by the FADEC (Full Authority Digital Electronic Control) system or the EHMS (Engine Health Monitoring System) on an aircraft engine. This distributed electronics demonstrator eliminates the need for the FADEC or EHMS to process the sensor signal, which will assist in making the overall system more accurate and efficient in processing only digital signals. This will offer weight savings in cables, harnesses and connector pin reduction. The design concept was to take the output from several on-engine sensors, carry out the signal conditioning, multiplexing, analogue to digital conversion and data transmission through a serial data bus. The unit has to meet the environmental requirements of DO-160 with the need to operate at 200°C, with short term operation at temperatures up to 250°C. The work undertaken has been to design an ASIC based on 1.0μm Silicon on Insulator (SOI) device technology incorporating sensor signal conditioning electronics for sensors including resistance temperature probes, strain gauges, thermocouples, torque and frequency inputs. The ASIC contains analogue multiplexers, temperature stable voltage band-gap reference and bias circuits, ADC, BIST, core logic, DIN inputs and two parallel ARINC 429 serial databuses. The ASIC was tested and showed to be functional up to a maximum temperature of 275°C. The ASIC has been integrated with other high temperature components including voltage regulators, a crystal oscillator, precision resistors, silicon capacitors within a hermetic hybrid package. The hybrid circuit has been assembled within a stainless steel enclosure with high temperature connectors. The high temperature electronics demonstrator has been shown to operate from −40°C to +250°C. This work has been carried out under the EU Clean Sky HIGHTECS project with the Project being led by Turbomeca (Fr) and carried out by GE Aviation Systems (UK), GE Research – Munich (D) and Oxford University (UK).


2019 ◽  
Vol 963 ◽  
pp. 633-636 ◽  
Author(s):  
Shintaroh Sato ◽  
Masahiro Masunaga ◽  
Yuki Mori ◽  
Nobuyuki Sugii ◽  
Akio Shima

We report the physical and electrical characterization of the inversion layer carrier and the shallow interface trap sites with n-and p-channel SiC-MOSFET in terms of high temperature electronics. This work proposes a physical model that explains the difference between Id-Vg measurement result and calculation result supposing the ideal condition with Pao and Sah double ideal in room temperature. The measurement at 500°C confirmed our model so that inversion carrier were thermally excided, they could not be easily trapped by shallow trap sites, and Id-Vg measurement result approached the ideal condition.


Author(s):  
M. Larsen ◽  
R.G. Rowe ◽  
D.W. Skelly

Microlaminate composites consisting of alternating layers of a high temperature intermetallic compound for elevated temperature strength and a ductile refractory metal for toughening may have uses in aircraft engine turbines. Microstructural stability at elevated temperatures is a crucial requirement for these composites. A microlaminate composite consisting of alternating layers of Cr2Nb and Nb(Cr) was produced by vapor phase deposition. The stability of the layers at elevated temperatures was investigated by cross-sectional TEM.The as-deposited composite consists of layers of a Nb(Cr) solid solution with a composition in atomic percent of 91% Nb and 9% Cr. It has a bcc structure with highly elongated grains. Alternating with this Nb(Cr) layer is the Cr2Nb layer. However, this layer has deposited as a fine grain Cr(Nb) solid solution with a metastable bcc structure and a lattice parameter about half way between that of pure Nb and pure Cr. The atomic composition of this layer is 60% Cr and 40% Nb. The interface between the layers in the as-deposited condition appears very flat (figure 1). After a two hour, 1200 °C heat treatment, the metastable Cr(Nb) layer transforms to the Cr2Nb phase with the C15 cubic structure. Grain coarsening occurs in the Nb(Cr) layer and the interface between the layers roughen. The roughening of the interface is a prelude to an instability of the interface at higher heat treatment temperatures with perturbations of the Cr2Nb grains penetrating into the Nb(Cr) layer.


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