The influence of pieces thickness on metallographic structure of welded joints

The main objective of this paper was to establish how the thickness of welded pieces influences the metallographic structure of welded joints. Thus were made a total of 6 samples, and from each sample were taken test specimens for metallographic analysis of the base material, the filler material respective heat affected zone (HAZ). The samples were carried out by welding process: metal active gases (MAG) using a steel E 36-4, and the welded pieces had a thickness between 10 and 24 mm. The welding regime was characterized by parameters Iw = 200 / A, Uw = 24 / V. The joint by welding pieces was “T” form and both piece used as the base and the piece used as heart for welded joint were made of sheets with different thicknesses

Sintering the beaks of the elevator manufactured by direct metal laser sintering (DMLS) process from Co - Cr alloy

In this paper, two prototypes of dental elevator was made by DMLS process, using a super alloy powder of Co – Cr (ST2724G), with Phenix Systems machine, type PXS & PXM Dental, one with a threaded tail and another with a cylindrical tail. The quality obtained for the elevator is better, thanks to the material used and to the manufacturing process. For the elevator prototypes there were performed some Finite element method (FEM) analysis to identify stress locations and displacements. It was realized corrosion test in artificial saliva Fusayama Meyer (pH 5,5) at temperature of 37 ± 1 °C for 24 hours and remarks the importance of post treatment after DMLS process to obtain a better corrosion resistance in vitro

Lathe machining in the era of industry 4.0: Remanufactured lathe with integrated measurement system for CNC generation of the rolling surfaces for railway wheels

© IFIP International Federation for Information Processing 2016. Many projects and researches in the field of remanufacturing of specialized lathes are presented in the specialized literature. In the process of design for remanufacturing, a great number of solutions contain different aspects and data important to consider. The paper presents important stages of theoretical and applied research regarding the modernization of a conventional lathe with two working units by adaptation of four driving chains for CNC advance/ positioning movements and improvements of translation couplings, adaptation of CNC equipment for driving and measuring simultaneous both wheels mounted on axle. The reducing of geometrical errors of the running profile is very important in reshaping the worn wheelsets. The lathe remanufacturing process involves the restoration of functional requirements and measurement of the geometric precision. The CNC capabilities of the remanufactured lathe require a database of parametric representation of profiles and rolling surfaces using CAD techniques according to international standards

Analysis on the measurement results of the precision grades and their influence on the performance of the hydraulic pumps with spur gears

© 2019 IOP Publishing Ltd. The paper presents results of experimental measurements on the main precision grades for a cylindrical spur gearing, from the assembly of a hydraulic pump integrated in a hydrostatic driving system. For the components of this assembly, the main stages of the design, material characteristics, constructive, precision and functional parameters that define the flow, the pressure of the hydraulic environment, the driving speed are briefly presented. The analysis was performed based on the data obtained by measuring the gears' deviations and tolerances. Among these, the most important data for complying the optimal requirements of the pump operating criteria were retained and analysed. The analysis of the measured results highlighted the main causes and effects of the deviations found. The presented results show the problem's complexity and are important in evaluating the performances that characterize these types of pumps, with wide use in many fields of hydraulic actuators

Augmented reality simulation of CAM spatial tool paths in prismatic milling sequences

© IFIP International Federation for Information Processing 2016. Augmented Reality (AR) technology to support learning activities becomes a trend in education and effective teaching aids for engineering courses. This paper presents initial results of a project aimed to transform the current learning process of Computer Aided Manufacturing (CAM) by designing and implementing an interactive AR learning and simulation tool to help students to develop a comprehensive understanding of technological models and features in milling processes. We present a marker-based platform that uses AR as a medium for representation of prismatic milling processes to facilitate CAM education and it should enable a faster comprehension of complex spatial paths and overall machining system

Rigid 3d registration algorithm for localization of the vertebral centroids in 3d deformity models of adolescent idiopathic scoliosis

© 2020 CAD Solutions, LLC. In this paper, we developed a methodology for a non-invasive 3D diagnosis based on a digitized dorsal surface of the patient enabling assessment and monitoring of Adolescent Idiopathic Scoliosis (AIS). We applied a novel 3D registration algorithm, which enables rigid transformation of 3D vertebral CAD models and localization of vertebrae centroids on the middle 3D spinal line to simulate the AIS. Registrations of the vertebral centroids on a 5th degree middle spinal B-Spline curve is the main step in establishing biomechanical relations of internal structure (deformed spine) with a digitized surface of patients and extracting the key diagnostic parameters of the AIS. This simulation algorithm is developed into PLM system CATIA using KAx tools and successfully evaluated on 372 AIS patients

Sintering the beaks of the elevator manufactured by direct metal laser sintering (DMLS) process from Co - Cr alloy

In this paper, two prototypes of dental elevator was made by DMLS process, using a super alloy powder of Co – Cr (ST2724G), with Phenix Systems machine, type PXS & PXM Dental, one with a threaded tail and another with a cylindrical tail. The quality obtained for the elevator is better, thanks to the material used and to the manufacturing process. For the elevator prototypes there were performed some Finite element method (FEM) analysis to identify stress locations and displacements. It was realized corrosion test in artificial saliva Fusayama Meyer (pH 5,5) at temperature of 37 ± 1 °C for 24 hours and remarks the importance of post treatment after DMLS process to obtain a better corrosion resistance in vitro

Design of handle elevators and ATR spectrum of material manufactured by stereolithography

© IFIP International Federation for Information Processing 2016. In medicine, the surgical instruments are realized using a variety of stainless steel, such as curved elevators. The quality and the price of surgical instruments differ in function of the manufacturing processes and the material used. This paper, presents a prototype of elevator, manufactured using two types of additive manufacturing process Direct Metal Laser Sintering – DMLS process for beaks and stereolithography process for the handles. The handle was made by means of stereolithography with the printer PROJET 1500, using a plastic material D638. The design and the quality obtained for the prototype of elevator is better, thanks to the material used and to the manufacturing process. The prototype of handle manufactured by stereolithography using the UV rays presents very good mechanical resistance and allows to be sterilized. For the handle of the elevator prototype there was performed a FEM analysis to identify stress locations and displacements. In this paper, was realized a Attenuated Total Reflection (ATR) analysis on the plastic material D638 to be examined directly in the solid state without further preparation