Effects Of Induction Heating On Thixoformed MWCNT-Al Alloy Composite

The aim of this paper is to investigate the effect of vertical induction heating on MWCNT-Al alloy composite during thixoforming. Several feedstocks of MWCNT-A356 alloy composite with a non-dendritic microstructure were prepared using a mechanical stirring of liquid casting. During thixoforming, the feedstocks were reheated up to the 50 % liquid fraction in the semi-solid state at 580 °C and compress into an upper mold. The heat distribution is determined by analyzing the microstructures and densities throughout the cross-sectional of the feedstock. After that, real time temperature monitoring is carried out using the EPAD-Base2 data acquisition systems, optical microscopic observations and electronic densimeter measurements were used, respectively at its surface, top, center, and bottom locations. The results show that the temperatures distribution is consistent with only ± 10 °C variation. The homogeneous heat distribution has also been observed by the similar coarsening rates of α-Al grain after thixoforming with the average grain diameter of 37.9 ± 22.8 µm and spherical factor (SF) of 0.564 ± 0.127, and the densities are almost identical of 2.675 ± 0.009 g/cm3, 2.676 ± 0.011 g/cm3 and 2.676 ± 0.007 g/cm3 at these locations. Therefore, the vertical induction heating in this study is suitable for thixoforming of the composite aluminium alloy

Influence Of Point And Helix Angle On Thrust Force And Delamination For One-Shot Drilling Of Carbon Fiber Reinforced Plastic (CFRP)

Drilling operation for CFRP parts in the aircraft industry assembly line is unavoidable. Delamination frequently occurs during drilling holes in CFRP and reduces the ability of CFRP parts to carry loads and affects its service life spend. Drill reamer is enhancing the drill bits option for oneshot drilling to save time and cost. This article aims to investigate the influence on the variation of point and helix angle of drill reamer to thrust force and delamination damage. Different drills with the variation of point and helix angle were used to drill unidirectional CFRP laminates panel separately. From the thrust force curve graph, drilling using drill reamer can be divided into three main stages. Point angle geometrical feature influence in stage I while, helix angle in stage III, whereas stage II act as an opener for the drilled hole. Its found that point angle in drill reamer act as pilot drill and helix angle significantly affect to drilled holes quality. Variation of point angle features affected the thrust force measurement for stage I of drilling. The minor righthand side helix angle reduces the delamination compared to straight flute but negatively affected when major helix angle applied. The suitable combination of drill reamers’ geometry features will enhance overall drilling qualities

Investigation Of Mechanical & Wear Characteristics Of T6 Heat Treated Thixoformed Aluminium Alloy Composite

Thixoforming of aluminium alloy has been making a strong presence in the near net shape part production for the automotive and aerospace industries due to its process superior properties output in comparison to the other conventional methods. Improvement of the properties would surely further add to the already advantageous process above others.This study investigates the mechanical and wear behaviours of thixoformed Al-Si-Cu alloy when multi-walled carbon nano tubes (MWCNT) infusing into the thixoforming process. A new approach established using the mechanical stirring casting techniques produces a well-bind composite mixture of non-dendritic aluminium mixed with different content (0.5, and 0.75) of MWCNTs. The approach enclosed the MWCNTs with 0.5wt.% of Magnesium (Mg) powder as a wetting agentinto an aluminium wrapping and stirred it with LM4 for 10 and 15 min interval inside a furnace. The feedstock produced would be thixoformed before finally being applying T5 and T6 heat treatment. The microstructure of eacH specimens is characterised while the mechanical (tensile and hardness) and wear properties aremeasured according to each requirement. The outcome shows formation of non-dendritic microstructure with homogeneous distribution phase of the MWCNTs within it. The DOE analysis of the highest MWCNT content and stirring time after a T6 heat treatment reveals the highest hardness and UTS result of 94.6 HV and 246.2 MPa respectively. The Taguchi analysis also reveals that heat treatment was the most significant factor contributing towards the improvement. The heat-treated samples increase the hardness and tensile strength approximately 30% compared to an as-cast and give around 20% increment of wear resistance to the specime