Effect of Mill Type on Morphology of AA6013 Aluminium Powder
In conventional recycling method, metal chips are cast after pressing and melting in electric arc furnace. Material loss occurs during the recycling from liquid metal due to the several reasons. Direct recycling method which produces the aluminium powder from aluminium chips using mechanical mill can be an alternative to conventional recycling method. Thus material and energy losses, and labour cost will be reduced by direct recycling method without melting. In this study, the particle morphology of powder direct recycled from AA6013 aluminium alloy chips with cryogenic, disc and ball type grinders is investigated. Mechanical milling resulted flaky and irregular shaped AA6013 particles. It was ascertained that the chips did not break sufficiently in despite of the long duration milling mechanisms by ball mill. Cryogenic mill provides the energy required for milling mechanisms to act. Disc mill has the highest impact energy was determined. Consequently, efficiency of ball mill is lower than the efficiency of cryogenic and disc type mills. Shape factors of powders produced with ball and cryogenic mills were found greater than that of the powder produced by disc mill. Disc mill has the most efficient and effective impact energy which produces the smaller particles per minute, was determined.
Evaluation of Antimicrobial Activity of ZnO Nanoparticles against Foodborne Pathogens
Nanoparticles (Nps) are particles that range in size from 1 to 100 nm. The high surface area to volume ratio provides Nps with quirky properties compared to its bulk form (Buzea et al., 2007). Nanostructures are predominantly categorized into organic and inorganic Nps, the last have received extraordinary attentions due to its ability to tolerate destructive processing conditions, controlled safety and extended shelf life (Stoimenov et al., 2002; Sawai, 2003; Wang, 2004). Among the inorganic Nps, ZnO Nps are semiconductors with a direct wide band gap (3.3 eV) near UV spectrum (Wang, 2004; Schmidt-Mende et al., International Journal of Current Microbiology and Applied Sciences ISSN: 2319-7706 Volume 8 Number 11 (2019) Journal homepage: http://www.ijcmas.com
Room temperature wear characteristics of Al-Si-Cd bearing alloys
Abstract The aim of the present work is to assess the behaviour of aluminium-silicon-cadmium bearing alloys, particularly the role of cadmium as a solid lubricant during wear testing at room temperature. Compositions of Al-Si-Cd alloy containing 3 wt.% and 5 wt.% silicon and 1–5 wt.% cadmium were prepared by a special plunging and stirring technique. Wear characteristics of as-cast alloy were studied under dry sliding conditions at a relative humidity of about 68% and an ambient temperature of 304 K. The wear volume was measured as a function of sliding distance, applied load, sliding velocity and alloy compositions by using a pin-on-disc wear test machine. Optical microscopy of wear debris and scanning electron microscopy of worn test pin surfaces revealed the interaction of the debris with mating surfaces and the mode of wear. It was found that cadmium worked as a solid lubricant and reduced wear and friction of the matrix alloy.