Synthesis of AA7075 Based 10 wt.% Graphite Reinforced Composites for High Damping Capacity

The damping capacity improvement in under seawater for torpedo cone is the main of the research work. In the proposed work, an induction furnace was used to fabricate aluminum alloy AA7075 by melting individual elements such as pure Al, Zn, Mg, and Cu, followed by 10 wt.% graphite with varying sizes of reinforcement C1 (3 to 10μm), C2 (53 to 66μm), and C3 (106 to 150μm). Ingot casting was made in steel mold of 45 45 120mm3 and then hot forged at 490ᵒC, followed by solutionizing and artificial aging. Composites characterized for optical, SEM, hardness, and DMA analysis for loss factor. The improved performance in damping capacity by 50% observed for the threshold modulus of particulate (volume to the surface) for C2 composite. The processing cycle of fabrication of composites has been established.

Geometric dimensions of mixed fodder portion at transportation by a chain-disk conveyor

Chain- disc conveyors are widely used in the organization of the distribution of fodder for livestock farms of different types due to the simplicity of design and high reliability conveyors of this type. The portion of mixed fodder, transported by chain- disc transporter, is characterized by the following geometric parameters: the length of the l1and l2sections, the angle forming the bulk of the slope, the radius R of the cylindrical part of the piece is equal to the radius of the conveyor fodder line. In accordance with the kinds of the transported forms of the bulk of the body, the mode of the chain- disk conveyor can be divided into three types: an unloaded conveyor, loaded conveyor, overloaded conveyor. The volume of fodder portions may be expressed as a function of the length of the cylindrical portion l1. When fodder’s driving on a gently sloping portions of conveyor sections, this function will have a different appearance under different loading modes. With the change in the angle of the conveyor, the character depending on the length of the cylindrical portion is not changed, only change the boundaries of reality functions for different boot modes. At the angle of inclination of the conveyor х = 400, the total angle of the slope forming the bulk φ+х = 900, i.e., the forming plane flatness becomes perpendicular to the axis of the conveyor, and a granular body takes the form of a cylinder. With such tilted of transporter, body particulate volume is a linear function of its length, and the conveyor operates in the linear regime only boot.

Microstructure and Mechanical Properties of In Situ TiB2/6061 Composites

In situ TiB2/6061 composites have been successfully synthesized through chemical reaction between 6061 master alloy, Al-3B master alloy and Ti powder. The composites fabricated by direct melt mixing method was investigated by Scanning Electron Microscope (SEM), Energy Dispersive x-ray Spectroscopy (EDS) and X-Ray Diffraction (XRD), The results shown the existence of TiB2particles. The size of most TiB2particles were just in micron level, and even reached to sub-micron level. The increase in microhardness and tensile strength for the as-prepared composites with 5% particulate volume fraction (PVF) are up to 26.8% and 51.2% respectively.