Improving Volumetric Accuracy of AM Part Using Adaptive Slicing of Octree Based Structure

In Additive Manufacturing (AM) processes, the layer-by-layer fabrication of complex geometries may lead to stair casing and thus error resulting in volumetric inaccuracies in the model. Using thinner slices reduces the staircase error and improves part accuracy but there is a tradeoff between number of layers and the build time for manufacturing part. This paper presents a octree based structure to improve the accuracy as well as reduces the build time. In the current work, firstly converting STL file into a modified boundary octree data structure (MBODS) and then calculating the non-uniform slice thicknesses (adaptive slicing) from the octree representation. This slice thickness at any height is computed from the AM machine parameters and the smallest octree size at that available height. After the computation of the variable slice thicknesses has been completed, the part is virtually manufactured and the part errors are calculated. The virtually manufactured part and physical models are inspected to evaluate the volumetric errors. This algorithm uses an octree approach to improve the volumetric accuracy. And build time for the two different case studies are also done.Mechanical Engineerin

A simple synthesis of 1,3-di-aryl-quinolone derivatives by palladium catalyzed cross-coupling reaction

698-705An efficient and novel method for the preparation of N-aryl-quinolone via enaminone synthesis has been described. Subsequent derivatization at 3 position has been accomplished by the palladium catalyzed Suzuki cross coupling reaction. Using this method, various aryl boronic acids as well as hetero aryl boronic acids have been coupled with 3-bromo-quinolone to generate the novel 1,3-di-aryl-quinolone derivatives. The key step quinolone ring formation has been achieved by intramolecular displacement reaction of enaminone 2 with suitably substituted ortho-fluoro group in the aromatic ring