scholarly journals Parameters Development for Optimum Deposition Rate in Laser DMD of Stainless Steel EN X3CrNiMo13-4

2021 ◽  
Author(s):  
Mohammad Dalaee ◽  
Eduardo Cerrutti ◽  
Indira Dey ◽  
Christian Leinenbach ◽  
Konrad Wegener
Keyword(s):  
Stainless Steel ◽  
Linear Regression ◽  
Aspect Ratio ◽  
Deposition Rate ◽  
Process Parameters ◽  
Regression Equations ◽  
Parameters Selection ◽  
Scan Speed ◽  
Powder Flow Rate ◽  
Regression Correlation

AbstractLaser Direct Metal Deposition (DMD) has been developed as a manufacturing process to deposit coatings on existing materials and proves advantageous in Additive Manufacturing (AM) of complex and precise components. However, it is necessary to carefully determine the proper process parameter combinations to make this method economically viable for industries. The intent of this study is to address enhancement in productivity of laser DMD of stainless steel EN X3CrNiMo13-4. Accordingly, the effects of the main laser process parameters of laser power P, scan speed v, powder flow rate $$\dot{\mathrm{m}}$$ m ˙ , and spot diameter s on track geometries and build-up rate are discussed. The regression analysis is conducted to derive correlations between the combined set of main parameters and deposition rate. The results show a good linear regression correlation of R2 >0.9 for the geometrical characteristic of aspect ratio, dilution, and deposition rate. The constructed processing map, using linear regression equations, presents proper process parameters selection in connection with deposition rate, aspect ratio, and dilution rate.

Multi-response optimization of CNC turning parameters of austenitic stainless steel 303 using Taguchi-based grey relational analysis

2020 ◽  
Vol 44 (4) ◽  
pp. 592-601
Author(s):  
S.R. Sundara Bharathi ◽  
D. Ravindran ◽  
A. Arul Marcel Moshi
Keyword(s):  
Stainless Steel ◽  
Process Parameters ◽  
Grey Relational Analysis ◽  
Removal Rate ◽  
Regression Equations ◽  
Turning Process ◽  
Cnc Turning ◽  
Relational Analysis ◽  
Grey Relational ◽  
Cnc Turning Process

Extensive research has been carried out to optimize the process parameters of several machining processes. Optimizing the influencing parameters of the turning operation is a precise action that determines the desired level of quality. This study focuses on the multi-criteria optimization of the CNC turning process parameters of stainless steel 303 (SS 303) material to achieve minimum surface roughness (Ra) with maximum material removal rate (MRR) by means of Taguchi-based grey relational analysis. A CNC machine was tested following Taguchi’s L9 orthogonal array design. Grey relational analysis was used as the multi-criteria optimization tool. The significance of each individual process parameter on the overall characteristics of the turned specimen was estimated using analysis of variance (ANOVA). Regression equations were generated using the input factors with the selected output parameters. In addition, a morphological study of the chips produced by the turning process was carried out using SEM images in order to relate the chip geometry with the output responses.

SINGLE-FACTOR LINEAR REGRESSION MODEL OF HODGKIN’S LYMPHOMA IN ADOLESCENTS

2017 ◽  
Vol 63 (2) ◽  
pp. 320-325
Author(s):  
Svetlana Kuleva ◽  
Svetlana Ivanova ◽  
Andrey Karitskiy ◽  
Darya Zvyagintseva
Keyword(s):  
Radiation Therapy ◽  
Linear Regression ◽  
Predictive Factors ◽  
Hodgkin’S Lymphoma ◽  
Risk Group ◽  
Hodgkin's Lymphoma ◽  
Regression Equations ◽  
Single Factor ◽  
Number Of Cycles ◽  
Selection Of

With the use of regression and dispersion analyzes conducted in this study it was possible to identify predictive factors that significantly worsen the prognosis of Hodgkin’s lymphoma in adolescents however constructed regression equations did not pass the quality assessment of the models, which did not allow them to be used for the construction of point and interval predictions. In a cohort of patients enrolled in the study a risk-adapted treatment program based on the risk group for stratification was conducted. Negative aspects of the results of our study could be related to the already selected volume of the program for these patients. In turn our analysis proves the validity of the selection of therapeutic loads (a number of cycles of polychemotherapy, doses of radiation therapy) depending on the risk group, into which the adolescent is stratified.

scholarly journals Parameters Optimization of Auxiliary Gas Process for Double-Wire SS316L Stainless Steel Arc Additive Manufacturing

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 190
Author(s):  
Wei Wu ◽  
Jiaxiang Xue ◽  
Wei Xu ◽  
Hongyan Lin ◽  
Heqing Tang ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Additive Manufacturing ◽  
Process Parameters ◽  
Evaluation System ◽  
Gas Flow ◽  
Interactive Effect ◽  
Parameters Optimization ◽  
Heat Accumulation ◽  
Auxiliary Process ◽  
Strength And Stiffness

Serious heat accumulation limits the further efficiency and application in additive manufacturing (AM). This study accordingly proposed a double-wire SS316L stainless steel arc AM with a two-direction auxiliary gas process to research the effect of three parameters, such as auxiliary gas nozzle angle, auxiliary gas flow rate and nozzle-to-substrate distance on depositions, then based on the Box–Behnken Design response surface, a regression equation between three parameters and the total score were established to optimized parameters by an evaluation system. The results showed that samples with nozzle angle of 30° had poor morphology but good properties, and increasing gas flow or decreasing distance would enhance the airflow strength and stiffness, then strongly stir the molten pool and resist the interference. Then a diverse combination of auxiliary process parameters had different influences on the morphology and properties, and an interactive effect on the comprehensive score. Ultimately the optimal auxiliary gas process parameters were 17.4°, 25 L/min and 10.44 mm, which not only bettered the morphology, but refined the grains and improved the properties due to the stirring and cooling effect of the auxiliary gas, which provides a feasible way for quality and efficiency improvements in arc additive manufacturing.

scholarly journals Effects of bracket design on critical contact angle

2013 ◽  
Vol 83 (5) ◽  
pp. 877-884 ◽  
Author(s):  
Xiaomo Liu ◽  
Peng Ding ◽  
Jiuxiang Lin
Keyword(s):  
Contact Angle ◽  
Stainless Steel ◽  
Linear Regression ◽  
Resistance To Sliding ◽  
The Relationship ◽  
State Resistance ◽  
Critical Contact ◽  
Bracket Design

ABSTRACT Objective: To explore how the position of the bracket slots relative to the archwire influences the friction between them, and how bracket design affects the critical contact angle (θc). Materials and Methods: Two kinds of stainless steel archwires (0.016 and 0.019 × 0.025-inch) were tested against four kinds of brackets (Transmission Straight Archwire bracket, Domestic MBT bracket, Tip-Edge Plus bracket, and BioQuick self-ligation bracket) in the dry state. Resistance to sliding (RS) was measured as an increase in contact angle (θ). The value of θc was calculated by two linear regression lines. Results: Friction remained stable when θ < θc, then increased linearly when θ > θc. The θc values of the Tip-Edge Plus bracket and Transmission Straight Archwire bracket were significantly larger than those for the Domestic MBT bracket and BioQuick self-ligation bracket. Conclusions: The relationship between the archwire and bracket slot significantly affects the resistance to sliding. The “edge-off” structure of the Tip-Edge Plus bracket and Transmission Straight Archwire bracket could help to increase the θc value, and to expand the passive configuration range.

Micro extrusion of high aspect ratio bi-lumen tubes using 17-4PH stainless steel feedstock

2020 ◽  
Vol 58 ◽  
pp. 443-457
Author(s):  
Sandeep Kuriakose ◽  
Paolo Parenti ◽  
Massimiliano Annoni
Keyword(s):  
Stainless Steel ◽  
Aspect Ratio ◽  
High Aspect Ratio

Methodology of Estimation of Fire Separation Distances between Construction Facilities by Calculation

2020 ◽  
Vol 1006 ◽  
pp. 93-100
Author(s):  
Vadym Nizhnyk ◽  
Yurii Feshchuk ◽  
Volodymyr Borovykov
Keyword(s):  
Mathematical Model ◽  
Heat Flux ◽  
Linear Regression ◽  
Ignition Temperature ◽  
Oil Products ◽  
Regression Equations ◽  
Fire Load ◽  
Literary Sources ◽  
Tabular Method

Based on analysis of appropriate literary sources we established that estimation of fire separation distances was based of two criteria: heat flux and temperature. We proposed to use “ignition temperature of materials” as principal criterion when determining fire separation distances between adjacent construction facilities. Based on the results derived while performing complete factorial we created mathematical model to describe trend of changing fire separation distances depending on caloric power of fire load (Q), openings factor of the external enclosing structures (k) and duration of irradiation (t); moreover, its adequacy was confirmed. Based on linear regression equations we substantiated calculation and tabular method for the determination of fire separation distances for a facility being irradiated which contains combustible or otherwise non-combustible façade and a facility where liquid oil products turn. We developed and proposed general methodology for estimation of fire separation distances between construction facilities by calculation.

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