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.
Processing and Microstructural Characterization of Metallic Powders Produced from Chips of AA2024 Alloy
Accumulated metal waste during machining of aluminum alloys is considered for further recycling to promote environmentally sustainable production. This study aims to characterize the ball-milling process of AA2024 aluminum chips as an alternative to the remelting procedure. The proposed processing modes provide a powder particle size distribution with a d50 of 100–325 μm after 100 min milling. Stearic acid, as a process control agent (PCA), slows down powder refinement if introduced at the early stages of milling. The powder tends to form a flake-shaped morphology owing to the impact of plastic deformation altered by the PCA. Microhardness variation is linked to the joint effect of voids, strengthening phases, mechanically affected zones, and grain structure. Further, the paper reports the crystallite sizes ranging from 25 nm to 45 nm and the lattice strain < 1%. Finally, an outlook on hot-powder compaction and the associated properties of the material are presented.
Chapter 1 – Nanotechnology: A Toolkit for Cell Behavior
Tissue engineering seeks to effectively manipulate cellular populations to improve the function of damaged or diseased tissues and organs. Many techniques can affect cell behavior; however, in order to maintain desirable function, scientists and engineers design solutions that are as biomimetic as possible. True biomimeticity is very challenging without the incorporation of nanotechnology. Since cells in human tissues are surrounded by a 3D hierarchical tissue extracellular matrix containing numerous nano components, a revolutionary change in tissue engineering is to explore biomimetic nanobiomaterials and advanced 3D nano/microfabrication techniques for creating novel tissue constructs and regulating cell behavior. This chapter will provide an overview of recent nanotechnology in tissue engineering applications. We will put special emphasis on integrating cutting-edge 3D nano/microfabrication techniques with nanobiomaterials for complex tissue and organ regeneration.