The purpose of this work was to investigate the structural, thermal, micromechanical and tribolog... more The purpose of this work was to investigate the structural, thermal, micromechanical and tribological properties of novel polymer/metal composite materials for bearing applications. Copper (Cu)-filled Acrylonitrile Butadiene Styrene (ABS) composites were mixed in a laboratory scale by an internal mixer with two blade impellers, and then injection-molded. Neat ABS, ABS+5wt% Cu, ABS+10wt% Cu, and ABS+15wt% Cu were the four materials that were tested. The dispersion of Cu particles in the ABS matrix was investigated using Scanning Electron Microscopy (SEM) and a micro-tomography scan. The filler particles have a uniform distribution in the matrix, according to the observations. The incorporation of ABS filler also refined an increase in the glass transition temperature from Differential Scanning Calorimetry (DSC) and less intensity in the amorphous phase by X-ray diffraction (XRD). Nanoindentation tests were carried out to characterize the micro-mechanical behavior of the composites. F...
Two disjoint filler materials in a powder form are added to a polycarbonate (PC) matrix. The micr... more Two disjoint filler materials in a powder form are added to a polycarbonate (PC) matrix. The micro sized additives are Graphite (Gr) and molybdenum disulfide (MoS2) introduced as layered solid lubricants. Two distinct development methodologies are employed in order to prepare the composites; the first process is industrial by using directly an injection molding machine, while the second process is composite preparation in a laboratory scale. The experimental results of the two process are compared. From friction and wear tests, it is established that MoS2 particles improved the wear resistance and reduced the coefficient of friction of steel/PC contact with both development methodologies. On the contrary, Gr decreases the tribological properties of PC. Fracture morphologies and x-ray micro-tomography are performed to characterize the microstructural aspects of PC/solid lubricant composites. Micrographs show microcracking, filler agglomeration and the presence of voids with direct in...
This paper deals with the health monitoring of rails. Many nondestructive techniques have been ap... more This paper deals with the health monitoring of rails. Many nondestructive techniques have been applied to rule on the health of rails. Ultrasonic guided waves (UGWs) technique is one among them. The current study focuses on this technique. First, it describes several kinds of defects that can occur in rails. Then, it presents the principle, advantages and limitations of UGW technique. The paper gathers as exhaustive as possible the previous works in which the said technique was used as a tool to monitor the health of rails. The paper put special emphasis on the use of UGW in structural health monitoring (SHM) context. In order to better understand the benefit/need of this technique in this context, by especially the non-specialist reader, a background concerning SHM is provided.
The purpose of this work was to investigate the structural, thermal, micromechanical and tribolog... more The purpose of this work was to investigate the structural, thermal, micromechanical and tribological properties of novel polymer/metal composite materials for bearing applications. Copper (Cu)-filled Acrylonitrile Butadiene Styrene (ABS) composites were mixed in a laboratory scale by an internal mixer with two blade impellers, and then injection-molded. Neat ABS, ABS+5wt% Cu, ABS+10wt% Cu, and ABS+15wt% Cu were the four materials that were tested. The dispersion of Cu particles in the ABS matrix was investigated using Scanning Electron Microscopy (SEM) and a micro-tomography scan. The filler particles have a uniform distribution in the matrix, according to the observations. The incorporation of ABS filler also refined an increase in the glass transition temperature from Differential Scanning Calorimetry (DSC) and less intensity in the amorphous phase by X-ray diffraction (XRD). Nanoindentation tests were carried out to characterize the micro-mechanical behavior of the composites. F...
Two disjoint filler materials in a powder form are added to a polycarbonate (PC) matrix. The micr... more Two disjoint filler materials in a powder form are added to a polycarbonate (PC) matrix. The micro sized additives are Graphite (Gr) and molybdenum disulfide (MoS2) introduced as layered solid lubricants. Two distinct development methodologies are employed in order to prepare the composites; the first process is industrial by using directly an injection molding machine, while the second process is composite preparation in a laboratory scale. The experimental results of the two process are compared. From friction and wear tests, it is established that MoS2 particles improved the wear resistance and reduced the coefficient of friction of steel/PC contact with both development methodologies. On the contrary, Gr decreases the tribological properties of PC. Fracture morphologies and x-ray micro-tomography are performed to characterize the microstructural aspects of PC/solid lubricant composites. Micrographs show microcracking, filler agglomeration and the presence of voids with direct in...
This paper deals with the health monitoring of rails. Many nondestructive techniques have been ap... more This paper deals with the health monitoring of rails. Many nondestructive techniques have been applied to rule on the health of rails. Ultrasonic guided waves (UGWs) technique is one among them. The current study focuses on this technique. First, it describes several kinds of defects that can occur in rails. Then, it presents the principle, advantages and limitations of UGW technique. The paper gathers as exhaustive as possible the previous works in which the said technique was used as a tool to monitor the health of rails. The paper put special emphasis on the use of UGW in structural health monitoring (SHM) context. In order to better understand the benefit/need of this technique in this context, by especially the non-specialist reader, a background concerning SHM is provided.
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