The Effect of Heat Treatment on Interface Properties of S45C Steel/Copper Compound Casting
ABSTRACT 
 
The bonding of an S45C steel inserted into copper during cast welding and heat treatment was examined. The interface shear strength was made with a push-out test. After cast welding, a cast-welding layer formed between steel and copper. After marquenching, martempering and austempering heat treatment, there was a cast-welding layer near the steel matrix, an irregular layer near the copper matrix and between of them was a middle layer. Through X-ray diffraction analysis was used to determine that the interface layer consisted of carbon and CuFeO2. Through electron probe X-ray microanalysis (EPMA), it was showed that iron atoms and carbons, mostly, diffused into the copper matrix. The interface shear strengths of the compound casting while with marquenching, martempering, and austempering were 6.29 MPa, 8.23 MPa, and 8.33 MPa, respectively; The fractured region was all happened near S45C steel matrix in the cast welding layer.
The fibre/matrix interfacial shear strength in titanium alloy matrix composites reinforced by silicon carbide or boron CVD filaments
Abstract The mechanical adhesion between CVD filaments (B, SiC) and titanium matrices was studied. Because a single fiber composite was chosen for this purpose, the critical length measurement and the shear strength were calculated using a statistical analysis. The study indicated the role played by the surface treatments of the fibers on the reinforcement/matrix adhesion. The conclusions obtained on model materials are in agreement with the results obtained on real composites.
Evaluation of CuAl2O4 as an Oxygen Carrier in Chemical-Looping Combustion
The chemical-looping combustion (CLC) process is a novel solution for efficient combustion with intrinsic separation of carbon dioxide. The process uses a metal oxide as an oxygen carrier to transfer oxygen from an air to a fuel reactor where the fuel, or gasification products of the fuel, reacts with the solid oxygen carrier. In this work, copper(II) aluminate (CuAl2O4) was assessed as a potential oxygen carrier using methane as fuel. The carrier particles were produced by freeze–granulation and calcined at 1050 °C for a duration of 6 h. The chemical-looping characteristics were evaluated in a laboratory-scale fluidized-bed reactor in the temperature range of 900–950 °C during 45 alternating redox cycles. The oxygen carrier exhibited reproducible and stable reactivity behavior in this temperature range. Neither agglomeration nor defluidization was noticed in any of the cycles carried out at 900–925 °C. However, after reactivity tests at 950 °C, soft agglomeration and particle fragmentation were observed. Systematic phase analysis of the Cu–Al–O system during the redox cycle was carried out as a function of duration of reduction and oxygen concentration during the oxidation period. It was found that the CuAl2O4 is reduced to copper(I) aluminate (CuAlO2; delafossite), Cu2O, and elemental Cu. The CuAlO2 phase is characterized by slow kinetics for oxidation into CuO and CuAl2O4. Despite this kinetic limitation, complete conversion of methane with reproducible reactivity of the oxygen carrier is achieved. Thus, CuAl2O4 could be a potential oxygen carrier for chemical-looping combustion.