anil borah

The effect of micro-alloying Sn (0.08 wt.%) on dry sliding abrasive wear behaviour of cast Al-Mg-Si alloy was investigated. Additionally, microstructure, hardness, and their impact on wear resistance were also investigated. It was observed that Sn contributes to the hardness and accelerates the age-hardening response of the Al-Mg-Si alloy. Sn addition also favours the formation of script-like Al(Fe, Mn)Si phase and increases the amount of Mg2Si precipitate. SEM investigation of worn surfaces reveals a similar abrasive wear mechanism in both the alloys which were micro-cracking, ploughing, and delamination. The study also reveals that improving the hardness by micro-alloying 0.08 wt.% Sn can prevent mass loss and marginally improves the wear resistance of the Al-Mg-Si.

In the present work, the effect of micro-alloying (0.02 wt%) of Titanium (Ti) in Aluminium (Al) alloys 2xxx series was studied with respect to its micro-hardness values. Two alloy compositions of Al–6.84Cu–0.02Mg (alloy-A) and Al–6.84Cu–0.02Mg–0.02Ti (alloy-B) were prepared by casting route. The alloys were subjected to different heat treatment conditions. Micro Vickers hardness tests were carried out for both the alloys under as-cast and heat treated conditions. Addition of 0.02 wt% Ti was found to have increased the hardness values of the 2xxx series Al-alloys under both as-cast and homogenized conditions by about 11%. Micro-alloying of 0.02 wt% Ti to 2xxx series Al-alloy was also compared with micro-alloying of 0.02 wt% Sn to the 2xxx Al alloy. In this case, hardness of Al–Ti micro-alloys were 5% higher compared the Al–Sn micro-alloys under both as-cast and homogenized conditions. In the present work surface morphology of the six samples of alloy-A and alloy-B were analysed using...

In this study both natural ageing (NA) and artificial ageing (AA) behaviour of Al-Mg-Si aluminium alloy having trace addition of 0.04 wt.% Sn (Tin) was studied at different solution heat treatment (SHT) temperature and time, ageing time and temperatures. Microstructural analysis was performed to identify the intermetallic phases. It was observed that peak NA hardness strongly depends on the SHT temperature and time. SHT at 530 for 0.5 hour, slows down the peak NA hardness attaining time of the alloy to a maximum of 5 days. But as the SHT time increases to 3.5 hours, the peak NA hardness attaining time reduced to 1 day. Alloy SHT at 530 for 1 hour attain a maximum peak hardness of HRB 24 during 3 days of NA. Artificial ageing improved the hardness of the NA alloy to a maximum of HRB 41 during 12 hours of ageing at 190 . The overall hardness of Al-Mg-Si-Sn as-cast alloy increases by 32 % during ageing process.

Tin (Sn) acts as an important role in the ageing behaviour of Al–Mg–Si alloy (6xxx series). In the present work the effect of micro-alloying of (0.04 wt% Sn) on the natural age hardening behaviour of Al–Mg–Si alloy is studied. Two alloy compositions of Al–1.2Mg–0.69Si and Al–1.2Mg–0.69Si–0.04Sn were prepared by casting process. Solution heat treatment of the two as-cast alloys was carried out at two different temperatures of 530 and 570 °C for 75 min followed by quenching in cold water at room temperature. The variation in the hardness with time for the alloys heat treated at different temperatures was recorded after post solutionising. Addition of 0.04 wt% Sn causes retardation in attaining peak hardness as compared to base alloy. Micro-alloying of Sn by 0.04 wt% in Al–Mg–Si alloy delayed in attaining the peak hardness value from 24 h (1 day) to 192 h (8 days).

Microstructure and mechanical properties of the cast and wrought Al–Mg–Si alloy micro-alloyed with 0.04 wt% and 0.08 wt% Sn were investigated at various processing conditions, viz. as-cast, solutionised, homogenised, hot rolled and peak-aged. Additionally, fracture surfaces of the alloys were also examined in the as-cast, peak-aged cast and peak-aged rolled conditions. It was observed that 0.04 wt% Sn favours the formation of a lamella-like eutectic Al + Mg 2 Si, whereas 0.08 wt% Sn favours the formation of plate/rod-like Mg 2 Si. The formation of the former deteriorated the hardness and tensile strength, but improves the ductility, whereas the formation of the later was found to contribute to the hardness, tensile strength as well as ductility of the Al–Mg–Si alloy. Homogenisation treatment had reduced the hardness of all the alloys to the lowest value due to the dissolution and spheroidisation of the intermetallic phases. However, hot rolling had significantly increased the hardne...

The impact behaviour of 6061 alloy with trace amount of 0, 0.04, and 0.08 wt.% Sn was studied in the as-cast (AC), as-roll (AR) and peak-age roll (PAR) processing state. Additionally, the fracture mechanism was also studied in the AC and PAR state. The experimental investigation revealed that at all processing states, trace addition of Sn improves the impact strength of the 6061 alloy. Compared to the other processing states, the PAR condition contribute most to the impact strength. Fractography analyses showed that the fracture in the alloys occurred primarily by the crack propagation of Al(Fe, Mn)Si particles. The fractures in the AC alloys took place by mixed ductile and brittle mode by larger ductile dimples, cracks and cleavages, while in the PAR alloys was primarily by ductile mode by the smaller dimple fractures.

Nano-crystalline RuAl was synthesised by mechanical alloying. The evolution of the nano-crystalline RuAl phase during the mechanical alloying process using ruthenium and aluminium powders was studied. During the milling process, the peaks corresponding to reflections from the aluminium planes disappeared. The variation of crystallite size and microstrain with milling time was evaluated using X-ray diffraction (XRD) patterns. though the XRD results showed the formation of a RuAl phase after 7h of milling, scanning electron microscopy studies revealed that the RuAl phase was formed after 2h of milling. The analysis revealed that average crystallite sizes of 17 and 120 nm were obtained for RuAl and Ru phases, respectively, during the milling process. Density value of 97 % of the theoretical value was obtained for the milled powder mixture after cold compaction and sintering.