A Machinability Study of Mild Steel using Abrasive Water Jet Machining Technology
Abrasive water jet machining is a non conventional machining process in which removal of material takes place by impact erosion of high pressure, high velocity of water and entrained high velocity of grit abrasives on a work piece. The objective of experimental investigation is to conduct research of machining parameters impact on Material removal rate and Surface roughness of work piece of Mild Steel (MS). The approach was based on Taguchi’s method, analysis of variance and signal to noise ratio (SN Ratio) to optimize the Abrasive Water Jet Machining process parameters for effective machining and to predict the optimal choice for each AWJM parameter such as Traverse speed, Abrasive flow rate, and Standoff distance. There is L9 orthogonal array used by varying Transverse Seed, Abrasive flow rate, standoff distance respectively and for each combination we have conducted three experiments and with the help of Signal to Noise ratio we find out the optimum results for AWJM. It was confirmed that determined optimal combination of AWJM process parameters satisfy the real need for machining of Mild Steel (MS) in actual practice.
A Review on Abrasive Water Jet Machining Process and its process parameters
Abrasive water jet machining (AWJM) is one of the recent non-traditional methods that have been used widely in industry for machining of different materials in a variety of applications. Material removal in this process is due to erosion of a small volume with each particle striking the surface at high velocity. The numbers of particles striking the surface are in the order of tens of thousands per second. It is highly suitable for ceramics and composite materials. Composite materials are being increasingly used in various applications like space, aircraft, marine, architectural and automobile sector because of their superior physical and mechanical properties even though they are a little bit costly. Machining of composite materials is of great interest because of variety of reinforcement from high strength fibers to natural fibers. There are so many process parameter affect quality of machined surface cut by AWJM. Important process parameters which mainly affect the quality of cutting are traverse speed, hydraulic pressure, stand of distance, abrasive flow rate and types of abrasive. Abrasive water jet machining provides some advantages over conventional and nonconventional machining process for cutting the composite materials like no thermal effect, high machining versatility and small cutting forces.
Rational Design, Synthesis and Evaluation of γ-CD-Containing Cross-Linked Polyvinyl Alcohol Hydrogel as a Prednisone Delivery Platform
This study describes the in-silico rational design, synthesis and evaluation of cross-linked polyvinyl alcohol hydrogels containing γ-cyclodextrin (γ-CDHSAs) as platforms for the sustained release of prednisone (PDN). Through in-silico studies using semi-empirical quantum mechanical calculations, the effectiveness of 20 dicarboxylic acids to generate a specific cross-linked hydrogel capable of supporting different amounts of γ-cyclodextrin (γ-CD) was evaluated. According to the interaction energies calculated with the in-silico studies, the hydrogel made from PVA cross-linked with succinic acids (SA) was shown to be the best candidate for containing γ-CD. Later, molecular dynamics simulation studies were performed in order to evaluate the intermolecular interactions between PDN and three cross-linked hydrogel formulations with different proportions of γ-CD (2.44%, 4.76% and 9.1%). These three cross-linked hydrogels were synthesized and characterized. The loading and the subsequent release of PDN from the hydrogels were investigated. The in-silico and experimental results showed that the interaction between PDN and γ-CDHSA was mainly produced with the γ-CDs linked to the hydrogels. Thus, the unique structures and properties of γ-CDHSA demonstrated an interesting multiphasic profile that could be utilized as a promising drug carrier for controlled, sustained and localized release of PDN.