102 research outputs found

    Numerical analysis of AZ61 magnesium alloy extrusion process by modified equal channel angular extrusion (ECAE) method

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    The paper presents the results of numerical modelling of AZ61 magnesium alloy hot deformation using modified ECAE method. The temperature-velocity conditions were analysed using FEM. The extrusion process was realised using the die with modified angular channel containing horizontal contracting zone in the material exit direction. The channels were arranged at right angle relatively to each other. The main aim of the numerical research was to determine the most favourable parameters of the extrusion that allow obtaining the products with good mechanical properties. The final product is a round rod that could be used as a material charge to further plastic deformation process

    The analysis of influence the parameters of rolling process in three high skew rolling mill of AZ31 magnesium alloy bars on temperature distribution

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    The work presents the results of numerical investigations of AZ31 magnesium alloy bars obtaining by the rolling process in a three high skew rolling mill. An analysis of impact the magnitude of inflicted deformation on temperature distribution in the material was made. The calculations were made using Finite Element Method (FEM) for 3D deformation state taking into account thermal phenomena that occur during applied deformation scheme. Theoretical investigations were made for two variants of deformation, one temperature of the process that equals 400 °C and four rolling rates of 25, 75 and 100 rev/min

    Production of magnesium-aluminium bimetallic bars using the explosive cladding method

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    The paper presents the results of the preparation of semi-finished products in the form of magnesium-aluminium round bimetallic bars by the explosive cladding method. The system of samples consisted of an aluminium tube (1050 grade) and magnesium bar (grade AZ31) was prepared. The analysis of microstructure and mechanical tests of the joint quality was carried out. On the base of obtained results it was found that the explosive cladding parameters used to obtain the semi-finished bimetallic product characterized by a slight ovality and mechanical connection of the individual layers were correct

    Microstructure and mechanical properties of forged and rolled rings made from X20Cr13 steel

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    The article describes the results of microstructure and mechanical properties tests (according to PN-EN ISO 6892- 1:2016-09 and PN-EN ISO 6507-1:2007), which were obtained on specimens taken from a fragment of a ring rolled in the temperature range from 1220 °C to 950 °C, with dimensions ø965/803 x 164 mm, annealed and heat-treated: quenching at the temperature of 1 030 ± 10 °C in oil and tempering at a temperature of 650 °C. The starting material for rolling was a forging with an opening of ø560/230 x 180 mm. Comparative hardness tests were also performed on specimens taken from the ring after rolling and softening annealing. The Rm>/sub>, Rp0.2 and A indices of the ring fragment after heat treatment, as assumed, were respectively: 942 MPa, 763 MPa and 17 %

    Ewaluation and analysis of the large-size forged and rolled en AW – 7057 alumminum alloy ring structure

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    The article presents the results of tests on the structure and hardness of a large-size ring made of EN AW - 7075 aluminium alloy produced under industrial conditions at the Zarmen FPA forge according to the developed technology - a combined forging and rolling method. Studies of the ring were carried out in order to assess its structure and hardness after the forming processes. The scope of the study included microscopic observations (microstructure and EDS), X-ray phase analysis and hardness distribution measurements

    Evaluation of strength parameters and structure analysis of an EN AW - 7075 aluminium alloy ring made by forging and rolling and heat-treated

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    The article presents the results of research on the evaluation of the structure and mechanical properties of a largesize ring made of aluminum alloy EN AW - 7075 according to a new technology, developed under the project “Innovative low-waste technology for forming large-size rings” carried out by Zarmen FPA forge with participation and support of the Lukasiewicz Research Network - Poznan Institute of Technology. Based on the tests, it was found that the produced ring was characterized by a homogeneous structure and the strength properties required by the customers

    Using the Systemic Immune-Inflammation Index (SII) as a mid-treatment marker for survival among patients with stage-III locally advanced non-small cell lung cancer (NSCLC)

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    The Systemic Immune-Inflammation Index (SII) is an important marker of immune function, defined as the product of neutrophil-to-lymphocyte ratio (NLR) and platelet count (P). Higher baseline SII levels have been associated with improved survival in various types of cancers, including lung cancer. Data were obtained from PROCLAIM, a randomized phase III trial comparing two different chemotherapy regimens pemetrexed + cisplatin (PEM) vs. etoposide + cisplatin (ETO), in combination with radiotherapy (RT) for the treatment of stage III non-squamous non-small cell lung cancer (NSCLC). We aimed to determine if SII measured at the mid-treatment window for RT (weeks 3-4) is a significant predictor of survival, and if the effect of PEM vs. ETO differs by quartile (Q) level of SII. Hazard-ratios (HR) for survival were estimated using a proportional hazards model, accounting for the underlying correlated structure of the data. A total of 548 patients were included in our analysis. The median age at baseline was 59 years. Patients were followed for a median of 24 months. Adjusting for age, body mass index, sex, race, and chemotherapy regimen, SII was a significant mid-treatment predictor of both overall (adjusted HR (aHR) = 1.6
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