Search results for "Formability"

Analysis of stamping performances of dual phase steels: A multi-objective approach to reduce springback and thinning failure

2009

The industrial interest on light weight components has contributed in the last years to a significant research effort on new materials able to guarantee high mechanical properties, good formability and reasonable costs together with reduced weights when compared to traditional mild steels. Among such materials advanced high strength steels (AHSS) such as transformations induced plasticity (TRIP) and dual phase (DP), and light weight alloys proved their usefulness in stamping of automotive components. As AHSS are concerned, one of the main drawbacks is related to springback occurrence. Many aspects have to be taken into account when springback reduction is investigated: material behavior iss…

Single-Point Incremental Forming of Titanium and Titanium Alloy Sheets.

2021

Incremental sheet forming of titanium and its alloys has a significant role in modern manufacturing techniques because it allows for the production of high-quality products with complex shapes at low production costs. Stamping processes are a major contributor to plastic working techniques in industries such as automotive, aerospace and medicine. This article reviews the development of the single-point incremental forming (SPIF) technique in titanium and its alloys. Problems of a tribological and microstructural nature that make it difficult to obtain components with the desired geometric and shape accuracy are discussed. Great emphasis is placed on current trends in SPIF of difficult-to-fo…

Acanthocytes in urinary sediment--a pathognomonic marker?

1998

On the improvement of material formability in SPIF operation through tool stirring action

2012

Single-point incremental forming (SPIF) is a quite new sheet-forming process which offers the possibility to deform complex parts without dedicated dies using a single-point tool and a standard three-axis CNC machine. The process mechanics enables higher strains with respect to traditional sheet-forming processes, but particular attention must be given to the maximum forming angle. In this paper, a new approach is proposed to enhance the material formability through a localized sheet heating as a consequence of the friction work caused by elevated tool rotational speeds. AA1050-O, AA1050-H24, and AA6082-T6 were utilized, and the reached temperatures were recorded by thermocouples, fixed to …

Diabetes mellitus: evaluation of erythrocyte and polymorphonuclear leukocyte rheology

2015

Aim: To explore red blood cells (RBC) and leukocyte rheology, that may be relevant in the pathophysiology of diabetes mellitus. Methods and Results: Significant alterations have been observed in RBC behaviour using several filtration techniques, but the exploration of RBC deformability by laser diffractometry did not show any abnormality. We have also employed microrheological methods based on fluorescence spectroscopy: membrane microviscosity was evaluated in ghosts, while in intact RBC we explored the membrane polarity gradient using fluorescent fatty acids, the phospholipid and protein lateral mobility using respectively pyrene and pyrene-3-maleimide. Alterations emerged only using the l…

Hemorheological benefits of omega-3 polyunsaturated fatty acids on erythrocyte deformability in renal transplanted patients

1994

Erythrocyte rheology in diabetes mellitus and hypertension

2009

Red blood cell deformability in multiple myeloma

2018

The aim of this study was the evaluation of the erythrocyte deformability in multiple myeloma (MM). We enrolled 29MM patients and we evaluated, on fasting venous blood, the erythrocyte deformability, expressed as elongation index, and examined using the diffractometric method. By comparing normal controls and MM patients, a significant decrease in erythrocyte deformability, especially at low shear stresses, was found. In this research paper we evaluated all the hypothesis for a possible explanation of the behaviour of red blood cell deformability in MM, even considering how the alteration of erythrocyte deformability worsens the microcirculatory flow in these patients in association with th…

Hemorheological abnormalities in human arterial hypertension

2014

Blood rheology is impaired in hypertensive patients. The alteration involves blood and plasma viscosity, and the erythrocyte behaviour is often abnormal. The hemorheological pattern appears to be related to some pathophysiological mechanisms of hypertension and to organ damage, in particular left ventricular hypertrophy and myocardial ischemia. Abnormalities have been observed in erythrocyte membrane fluidity, explored by fluorescence spectroscopy and electron spin resonance. This may be relevant for red cell flow in microvessels and oxygen delivery to tissues. Although blood viscosity is not a direct target of antihypertensive therapy, the rheological properties of blood play a role in the…

The effect of human proinsulin C-peptide on erythrocyte deformability in patients with Type I diabetes mellitus.

1999

Aims/hypothesis. In recent years, evidence has arisen that proinsulin C-peptide exerts biological effects especially on microcirculation, e. g. C-peptide has been shown to increase skin microcirculation in patients with Type I (insulin-dependent) diabetes mellitus and to activate endothelial nitric oxide synthase. This study aimed to investigate the influence of proinsulin C-peptide on erythrocyte deformability which was assessed by means of laser diffractoscopy. Methods. Blood samples from healthy control subjects (n = 10) and Type I diabetic patients (n = 15) completely deficient of C-peptide were analysed at shear stresses ranging from 0.3 to 30 Pa. Results. Erythrocyte deformability was…