Review of Recent Development in Deep Drawing Process
Deep drawing is a common metal forming process used to manufacture recessed threedimensional parts from flat sheet metals. The research in deep drawing has been generic over the last few decades and various aspects of this process have been investigated. The paper aims to review the following aspects of deep drawing process that affect the quality of the product, tooling life and process design: i. The development of a theoretical model for the isoviscous hydrodynamic lubrication of deep drawing and its comparison with experimental results, the effect of lubrication on die expansion that could be used as an indirect means of detecting and measuring the presence of a hydrodynamic lubricant film thickness. ii. The improvement in deep drawing tooling that covers analysis for the blank holder, the effect of punch geometry on the deep drawing process, and introducing an alternative tooling materials for batch production. iii. The recent developments and future direction of research.
Hydrodynamic lubrication of the ironing process
A theoretical model is presented to calculate the lubricant film thickness in an unsteady hydrodynamic lubrication of cup‐shaped products to be formed by the ironing process. The model covers the development of hydrodynamic lubrication in various phases of the ironing process. The model provides equations for estimating the lubricant film thickness for each phase.
Right coronary artery stenosis associated with tricuspid valve ring annuloplasty
A 70-year-old man with severe symptomatic functional mitral valve regurgitation underwent successful mitral valve repair combined with tricuspid valve ring annuloplasty. Pre-operative coronary angiography (CAG) showed no significant stenosis. One-and-a-half years later, the patient presented with an acute exacerbation of heart failure. Repeat CAG demonstrated tight stenosis in the right coronary artery (RCA) with arterial kinking that corresponded to the same point as the stenosis where the RCA is the closest to the tricuspid valve ring. The new lesion probably occurred as a consequence of the tricuspid valve ring annuloplasty.