It is aimed to investigate the efficiency of nitrogen gas cooling which is used in aluminium extrusion mold in this study. The exit temperature of extrusion profile increases depending on heat generated by friction an...It is aimed to investigate the efficiency of nitrogen gas cooling which is used in aluminium extrusion mold in this study. The exit temperature of extrusion profile increases depending on heat generated by friction and forming. This situation can cause to surface defects such as hot cracks and grain thickening after extrusion process. Cooling of the mold has a critical role in terms of dissipating heat close to the forming zone. Local internal cooling experiments were performed in the hot aluminium extrusion mold within the scope of this study. It has been obtained that exit temperature of the aluminium extrusion profile can be significantly reduced in experimental results. Also it was found that the reduction of press time (s) and increase of press speed (mm/s). This paper focuses the effect of nitrogen gas cooling on extrusion mold for process efficiency. The extrusion parameters were performed for comparative analysis. Its obtained that process ensures efficiency.展开更多
The galvanic corrosion behaviour of alumiuium 3004 - ∝ brass with different area ratios was studied in the tropical marine atmosphere at Tuticorin harbour over a period of 426 days. The area ratios, viz. AAluminiurn...The galvanic corrosion behaviour of alumiuium 3004 - ∝ brass with different area ratios was studied in the tropical marine atmosphere at Tuticorin harbour over a period of 426 days. The area ratios, viz. AAluminiurn：A∝ brass, studied were 0.125, 0.25, 0.5, 1, 2, 4 and 8. The galvanic corrosion behaviour of the metals was studied in terms of the relative increase in the corrosion rate of aluminium due to galvanic coupling with oc brass, the relative decrease in the corrosion rate of ∝ brass due to galvanic coupling with aluminium, and the susceptibility of aluminium to pitting owing to galvanic coupling with ∝ brass. The galvanic potential and galvanic current of the system were monitored. Pits of different dimensions ranging from mild etchings to perforations were experienced on the borders arid the surfaces of the interface of aluminium in contact with ∝ brass. The corrosion products resulting from galvanic corrosion were analysed using XRD and the pitting on aluminium as a result of galvanic corrosion was highlighted in terms of pit depth, size and density of pit, using a high resolution microscope. The most favourable area ratio of aluminium - ∝ brass in marine atmosphere in terms of gravimetric corrosion rate is 8：1 and the most unfavourable area ratio of aluminium - ∝ brass is 1：4.展开更多
文摘It is aimed to investigate the efficiency of nitrogen gas cooling which is used in aluminium extrusion mold in this study. The exit temperature of extrusion profile increases depending on heat generated by friction and forming. This situation can cause to surface defects such as hot cracks and grain thickening after extrusion process. Cooling of the mold has a critical role in terms of dissipating heat close to the forming zone. Local internal cooling experiments were performed in the hot aluminium extrusion mold within the scope of this study. It has been obtained that exit temperature of the aluminium extrusion profile can be significantly reduced in experimental results. Also it was found that the reduction of press time (s) and increase of press speed (mm/s). This paper focuses the effect of nitrogen gas cooling on extrusion mold for process efficiency. The extrusion parameters were performed for comparative analysis. Its obtained that process ensures efficiency.
基金Supported by the CSIR-CECRI under project No.MLP 0008
文摘The galvanic corrosion behaviour of alumiuium 3004 - ∝ brass with different area ratios was studied in the tropical marine atmosphere at Tuticorin harbour over a period of 426 days. The area ratios, viz. AAluminiurn：A∝ brass, studied were 0.125, 0.25, 0.5, 1, 2, 4 and 8. The galvanic corrosion behaviour of the metals was studied in terms of the relative increase in the corrosion rate of aluminium due to galvanic coupling with oc brass, the relative decrease in the corrosion rate of ∝ brass due to galvanic coupling with aluminium, and the susceptibility of aluminium to pitting owing to galvanic coupling with ∝ brass. The galvanic potential and galvanic current of the system were monitored. Pits of different dimensions ranging from mild etchings to perforations were experienced on the borders arid the surfaces of the interface of aluminium in contact with ∝ brass. The corrosion products resulting from galvanic corrosion were analysed using XRD and the pitting on aluminium as a result of galvanic corrosion was highlighted in terms of pit depth, size and density of pit, using a high resolution microscope. The most favourable area ratio of aluminium - ∝ brass in marine atmosphere in terms of gravimetric corrosion rate is 8：1 and the most unfavourable area ratio of aluminium - ∝ brass is 1：4.
