This study aims to understand the distribution of reinforcement material in the matrix,evaluate the adherence between layers,and determine the air gap between printing roads.We printed the specimen with two different ...This study aims to understand the distribution of reinforcement material in the matrix,evaluate the adherence between layers,and determine the air gap between printing roads.We printed the specimen with two different composite materials,Polylactic Acid(PLA)reinforced with acrylic particles,and another filament reinforced with short carbon fibers.For the observations of the samples,we used a Confocal Microscope.We estimated the porosity of the material by comparing the expected mass with that achieved after manufacture.By pixel count,after binarization,we found the average percentage of acrylate particulate.They showed fair distribution through the PLA matrix even after the manufacturing process.The determination of fibers alignment was made by binarization of image,together with k-means and edge detection.This combination of methods allows estimating the fiber alignment by orientation straight lines.The manufacturing process did not offer good alignment of the fibers,even with the filament initially well aligned.展开更多
This paper aims to verify the Cu9Al4 phase influence on the nanomechanical behavior of the Cu-14Al-4Ni-xTi alloy obtained by rapid solidification with addition of different amounts of Ti.Using the Scanning Electron Mi...This paper aims to verify the Cu9Al4 phase influence on the nanomechanical behavior of the Cu-14Al-4Ni-xTi alloy obtained by rapid solidification with addition of different amounts of Ti.Using the Scanning Electron Microscopy(SEM),Atomic Force Microscopy(AFM),Energy Dispersion Spectroscopy(EDS)and X-Ray Diffraction(XRD),it was possible to perform the samples’microstructural characterization.In addition,the reduction of the Cu9Al4 phase precipitation and the X-phase appearance were verified according to the increase of the titanium percentage added.The nanomechanical behavior was evaluated by nanoindentation tests,which showed a significant decrease of the elastic modules and an increase of the Poisson coefficient’s according to the titanium amount.This research establishes that the reduction of Cu9Al4 phase implies on the increase of the capacity to dissipate energy.Therefore,the high damping capacity combined with the X-phase presence increases the super elasticity and the alloy ductility.展开更多
The present research aimed to analyze the influence that different contents of titanium(x=0.5,0.6 and 0.7 wt.%)have on the martensitic transformation temperature of a Cu-14Al-4Ni(wt.%)SMA(shape memory alloy).The Cu-14...The present research aimed to analyze the influence that different contents of titanium(x=0.5,0.6 and 0.7 wt.%)have on the martensitic transformation temperature of a Cu-14Al-4Ni(wt.%)SMA(shape memory alloy).The Cu-14Al-4Ni-xTi samples were casted in an arc-melting furnace and rapidly solidified.All samples underwent heat treatment in a tubular furnace at a temperature of 1,100°C for 30 min and water quenched at 25°C.Subsequently,samples were analyzed by SEM(scanning electron microscopy)with EDS(energy dispersive spectroscopy),XRD(X-ray diffraction)and DSC(differential scanning calorimeter).SEM images and XRD patterns showed that the presence of titanium modified the alloy’s microstructure,induced the formation of three titanium rich phases called“X”phase(CuNi2Ti,Cu3Ti and AlCu2Ti)and reduced the presence of the brittle phaseγ2(Cu9Al4)for samples with 0.6 and 0.7 wt.%Ti.The titanium added to the copper based SMA also functioned as a refiner,reducing GS(grain size)up to approximately 80%with the increase of Ti content.DSC results exhibited low enthalpy levels,hysteresis,as well as low start martensitic transformation temperatures.展开更多
文摘This study aims to understand the distribution of reinforcement material in the matrix,evaluate the adherence between layers,and determine the air gap between printing roads.We printed the specimen with two different composite materials,Polylactic Acid(PLA)reinforced with acrylic particles,and another filament reinforced with short carbon fibers.For the observations of the samples,we used a Confocal Microscope.We estimated the porosity of the material by comparing the expected mass with that achieved after manufacture.By pixel count,after binarization,we found the average percentage of acrylate particulate.They showed fair distribution through the PLA matrix even after the manufacturing process.The determination of fibers alignment was made by binarization of image,together with k-means and edge detection.This combination of methods allows estimating the fiber alignment by orientation straight lines.The manufacturing process did not offer good alignment of the fibers,even with the filament initially well aligned.
基金The authorswould like to thankthe Federal Institute of Science and Technology of Bahia,the University of Sao Paulo and the University of Brasilia for all the support to carry out this research.
文摘This paper aims to verify the Cu9Al4 phase influence on the nanomechanical behavior of the Cu-14Al-4Ni-xTi alloy obtained by rapid solidification with addition of different amounts of Ti.Using the Scanning Electron Microscopy(SEM),Atomic Force Microscopy(AFM),Energy Dispersion Spectroscopy(EDS)and X-Ray Diffraction(XRD),it was possible to perform the samples’microstructural characterization.In addition,the reduction of the Cu9Al4 phase precipitation and the X-phase appearance were verified according to the increase of the titanium percentage added.The nanomechanical behavior was evaluated by nanoindentation tests,which showed a significant decrease of the elastic modules and an increase of the Poisson coefficient’s according to the titanium amount.This research establishes that the reduction of Cu9Al4 phase implies on the increase of the capacity to dissipate energy.Therefore,the high damping capacity combined with the X-phase presence increases the super elasticity and the alloy ductility.
基金The authors would like to thank the Federal Institute of Science and Technology of Bahia,the University of São Paulo,the University of Brasilia and the PRPGI for all the support to carry out this research.
文摘The present research aimed to analyze the influence that different contents of titanium(x=0.5,0.6 and 0.7 wt.%)have on the martensitic transformation temperature of a Cu-14Al-4Ni(wt.%)SMA(shape memory alloy).The Cu-14Al-4Ni-xTi samples were casted in an arc-melting furnace and rapidly solidified.All samples underwent heat treatment in a tubular furnace at a temperature of 1,100°C for 30 min and water quenched at 25°C.Subsequently,samples were analyzed by SEM(scanning electron microscopy)with EDS(energy dispersive spectroscopy),XRD(X-ray diffraction)and DSC(differential scanning calorimeter).SEM images and XRD patterns showed that the presence of titanium modified the alloy’s microstructure,induced the formation of three titanium rich phases called“X”phase(CuNi2Ti,Cu3Ti and AlCu2Ti)and reduced the presence of the brittle phaseγ2(Cu9Al4)for samples with 0.6 and 0.7 wt.%Ti.The titanium added to the copper based SMA also functioned as a refiner,reducing GS(grain size)up to approximately 80%with the increase of Ti content.DSC results exhibited low enthalpy levels,hysteresis,as well as low start martensitic transformation temperatures.
