scholarly journals MACHINABILITY ANALYSIS OF AN AL-1,2% Pb ALLOY SOLIDIFIED IN A HORIZONTAL DIRECTIONAL DEVICE

2019 ◽  
Vol 16 (31) ◽  
pp. 860-874
Author(s):  
Jacson Malcher NASCIMENTO ◽  
Regiane Socorro BARROS ◽  
Camila Yuri KONNO ◽  
Adrina Paixão SILVA ◽  
Otávio ROCHA ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tool Wear ◽  
Tribological Behavior ◽  
Structural Parameters ◽  
Cutting Temperature ◽  
Industrial Processes ◽  
Unsteady State ◽  
Flow Conditions ◽  
Monotectic Alloy ◽  
Machinability Analysis

In general, the binary monotectic alloys are characterized by the limited solubility in the liquid state, which gives them a benefited tribological behavior such as wear resistance. Researches regarding the development of monotectic alloy microstructures during the unsteady-state heat flow conditions are fundamental, as it encompasses most of the solidification industrial processes. However, the microstructural relationship between the mechanical properties of monotectic alloys is little explored and practically nil. In this context, the present study consists of investigating and correlating solidification thermal variables and structural parameters such as microhardness and machinability (cutting temperatures and tool wear) of Al-1.2wt% Pb alloy, in a horizontal directional device. It was observed that the cutting temperature and tool wear results complement each other when correlated with position and interphase spacing, indicating that for smaller interphase spacings the addition of lead harms machinability.

Analysis of the Microstructural Evolution during the Transient Upward, Downward and Horizontal Directional Solidification of the Al-1.2wt%Pb Monotectic Alloy

2016 ◽  
Vol 869 ◽  
pp. 429-434 ◽  
Author(s):  
Camila Yuri Negrão Konno ◽  
Angela J. Vasconcelos ◽  
André Santos Barros ◽  
Adrina P. Silva ◽  
Otávio Fernandes Lima da Rocha ◽  
...  
Keyword(s):  
Directional Solidification ◽  
Microstructural Evolution ◽  
Convective Flow ◽  
Tribological Behavior ◽  
Eutectic Growth ◽  
Monotectic Reaction ◽  
Flow Conditions ◽  
Power Functions ◽  
Monotectic Alloy ◽  
Transient Heat Flow

Monotectic alloys are of great industrial importance because of their favorable tribological behavior. Many studies in order to better understand the morphologies obtained by monotectic reaction have been developed. To better understand the morphologies obtained by monotectic Al-1.2wt%Pb alloy reaction, especially in relation to induced convective flow, this paper aims to compare the microstructural evolution of the alloy obteind by directional solidification in transient heat-flow conditions in upward, downwand and horizontal solidification devices. It was observed a morphology transition from particles to fibers on upward and downward cases and a morphology of only particles on the horizontal case. The classical relationship used for eutectic growth, λ2v = C, which was considered applicable to monotectic reactions, didn’t seemed to be valid in the interphase spacing evolution for the downward device, however power functions (λ = C.va) were found in all cases.

Analysis of the Cutting Temperatures along the Macrostructure of a Directionally Solidified Al-7wt%Si Alloy

2015 ◽  
Vol 365 ◽  
pp. 116-121 ◽  
Author(s):  
Adrina P. Silva ◽  
I.R. Prado ◽  
J.S. Barros ◽  
C.A.P. Silva ◽  
A.L. Moreira ◽  
...  
Keyword(s):  
Heat Flow ◽  
Directional Solidification ◽  
Experimental Approach ◽  
Cutting Temperature ◽  
Columnar Structure ◽  
Thermal Parameters ◽  
Unsteady State ◽  
Flow Conditions ◽  
Directionally Solidified ◽  
Columnar To Equiaxed Transition

The aim of this research is to investigate the influence of solidification thermal parameters on the macrostructure of an Al-7wt%Si alloy during the horizontal directional solidification under unsteady-state heat flow conditions and its correlation with cutting temperatures. The solidification experiments were instrumented by thermocouples and an experimental approach was developed to quantitatively determine the solidification thermal parameters considered. The observation of the macrostructures has indicated that the columnar-to-equiaxed transition occurred in a sharp plane parallel to the chill wall and a higher average cutting temperature was obtained for the columnar structure.

Research Status of Subsequent Machining of Laser Cladding Layers

2020 ◽  
Vol 15 ◽  
Author(s):  
Lei Li ◽  
Yujun Cai ◽  
Guohe Li ◽  
Meng Liu
Keyword(s):  
Tool Wear ◽  
Surface Quality ◽  
Laser Cladding ◽  
Wear Surface ◽  
Chip Formation ◽  
Cutting Temperature ◽  
Dimensional Accuracy ◽  
Cutting Parameters ◽  
Cladding Layer ◽  
Cladding Layers

Background: As an important method of remanufacturing, laser cladding can be used to obtain the parts with specific shapes by stacking materials layer by layer. The formation mechanism of laser cladding determines the “Staircase effect”, which makes the surface quality can hardly meet the dimensional accuracy of the parts. Therefore, the subsequent machining must be performed to improve the dimensional accuracy and surface quality of cladding parts. Methods: In this paper, chip formation, cutting force, cutting temperature, tool wear, surface quality, and optimization of cutting parameters in the subsequent cutting of laser cladding layer are analyzed. Scholars have expounded and studied these five aspects but the cutting mechanism of laser cladding need further research. Results: The characteristics of cladding layer are similar to that of difficult to machine materials, and the change of parameters has a significant impact on the cutting performance. Conclusion: The research status of subsequent machining of cladding layers is summarized, mainly from the aspects of chip formation, cutting force, cutting temperature, tool wear, surface quality, and cutting parameters optimization. Besides, the existing problems and further developments of subsequent machining of cladding layers are pointed out. The efforts are helpful to promote the development and application of laser cladding remanufacturing technology.

scholarly journals Properties of Journal Bearing Materials That Determine Their Wear Resistance on the Example of Aluminum-Based Alloys

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 535
Author(s):  
Alexander Mironov ◽  
Iosif Gershman ◽  
Eugeniy Gershman ◽  
Pavel Podrabinnik ◽  
Ekaterina Kuznetsova ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Wear Resistance ◽  
Journal Bearing ◽  
Tribological Behavior ◽  
Secondary Structures ◽  
Magnesium Content ◽  
Wear Rates ◽  
Relative Extension ◽  
Bearing Materials ◽  
Antifriction Alloys

Potential relations of tribological characteristics of aluminum antifriction alloys with their compositions and mechanical properties were investigated. In this regard, the properties of eight aluminum alloys containing tin from 5.4% to 11% doped with lead, copper, silicon, zinc, magnesium, and titanium were studied. Mechanical properties such as hardness, strength, relative extension, and impact strength were analyzed. Within the tribological tests seizure load and wear of material were evaluated and secondary structures were studied afterwards. The absence of a definitive correlation between tribological behavior and mechanical properties was shown. It was determined that doping tin over 6% is excessive. The seizure load of the alloys increases with the magnesium content. Secondary structures of the alloys with higher wear rates contain one order less magnesium and tin.

scholarly journals Investigation of the Wear Behavior of PVD Coated Carbide Tools during Ti6Al4V Machining with Intensive Built Up Edge Formation

Coatings ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 266
Author(s):  
M.S.I. Chowdhury ◽  
B. Bose ◽  
S. Rawal ◽  
G.S. Fox-Rabinovich ◽  
S.C. Veldhuis
Keyword(s):  
Tool Wear ◽  
Titanium Alloys ◽  
Wear Behavior ◽  
Cutting Temperature ◽  
Ti6al4v Alloy ◽  
Adhesive Interaction ◽  
Heavy Load ◽  
Micromechanical Properties ◽  
Rough Turning ◽  
Coated Carbide

Tool wear phenomena during the machining of titanium alloys are very complex. Severe adhesive interaction at the tool chip interface, especially at low cutting speeds, leads to intensive Built Up Edge (BUE) formation. Additionally, a high cutting temperature causes rapid wear in the carbide inserts due to the low thermal conductivity of titanium alloys. The current research studies the effect of AlTiN and CrN PVD coatings deposited on cutting tools during the rough turning of a Ti6Al4V alloy with severe BUE formation. Tool wear characteristics were evaluated in detail using a Scanning Electron Microscope (SEM) and volumetric wear measurements. Chip morphology analysis was conducted to assess the in situ tribological performance of the coatings. A high temperature–heavy load tribometer that mimics machining conditions was used to analyze the frictional behavior of the coatings. The micromechanical properties of the coatings were also investigated to gain a better understanding of the coating performance. It was demonstrated that the CrN coating possess unique micromechanical properties and tribological adaptive characteristics that minimize BUE formation and significantly improve tool performance during the machining of the Ti6Al4V alloy.

Changes of Selected Structural and Mechanical Properties of the Strzelin Granites As Induced By Thermal Loads / Wpływ Obciążeń Termicznych Na Zmiany Niektórych Strukturalnych I Mechanicznych Właściwości Granitów Strzelińskich

2012 ◽  
Vol 57 (4) ◽  
pp. 951-974 ◽  
Author(s):  
Andrzej Nowakowski ◽  
Mariusz Młynarczuk
Keyword(s):  
Mechanical Properties ◽  
Nuclear Waste ◽  
Structural Changes ◽  
Structural Parameters ◽  
Total Porosity ◽  
Fracture Network ◽  
Qualitative Description ◽  
Temperature Changes ◽  
Heating And Cooling ◽  
Waste Repositories

Abstract Temperature is one of the basic factors influencing physical and structural properties of rocks. A quantitative and qualitative description of this influence becomes essential in underground construction and, in particular, in the construction of various underground storage facilities, including nuclear waste repositories. The present paper discusses the effects of temperature changes on selected mechanical and structural parameters of the Strzelin granites. Its authors focused on analyzing the changes of granite properties that accompany rapid temperature changes, for temperatures lower than 573ºC, which is the value at which the β - α phase transition in quartz occurs. Some of the criteria for selecting the temperature range were the results of measurements carried out at nuclear waste repositories. It was demonstrated that, as a result of the adopted procedure of heating and cooling of samples, the examined rock starts to reveal measurable structural changes, which, in turn, induces vital changes of its selected mechanical properties. In particular, it was shown that one of the quantities describing the structure of the rock - namely, the fracture network - grew significantly. As a consequence, vital changes could be observed in the following physical quantities characterizing the rock: primary wave velocity (vp), permeability coefficient (k), total porosity (n) and fracture porosity (η), limit of compressive strength (Rσ1) and the accompanying deformation (Rε1), Young’s modulus (E), and Poisson’s ratio (ν).

Modeling of Cutting Process with Cutter Axis Inclination

2011 ◽  
Vol 223 ◽  
pp. 66-74 ◽  
Author(s):  
Takashi Matsumura
Keyword(s):  
Tool Wear ◽  
Surface Finish ◽  
Cutting Temperature ◽  
Cutting Process ◽  
Mechanistic Models ◽  
End Mill ◽  
High Quality ◽  
Ball End Mill ◽  
Milling Operations ◽  
Edge Roughness

Multi-axis controlled machining has been increasing with the demand for high quality in mold manufacturing. The cutter axis inclination should be properly determined in the milling operations. The paper discusses the cutting process of ball end mill with the cutter axis inclination. Two mechanistic models are presented to show the effect of the cutter axis inclination on the tool wear and the surface finish. The actual cutting time during a rotation of the cutter reduces with increasing the cutter axis inclination. Then, the tool is cooled in the non-cutting time. The tool wear is suppressed with reducing the cutting temperature. The surface finish is also improved by increasing cutting velocities with the cutter axis inclination. When the cutter is inclined in the feed direction, the effect of the edge roughness on the surface finish is eliminated. The discussion based on the simulation is verified in the cutting tests for brittle materials.

Monitoring of Cutting Conditions with Dry Cutting on CNC Turning Machine

2010 ◽  
Vol 443 ◽  
pp. 382-387 ◽  
Author(s):  
Somkiat Tangjitsitcharoen ◽  
Suthas Ratanakuakangwan
Keyword(s):  
Surface Roughness ◽  
Tool Wear ◽  
Cutting Forces ◽  
Cutting Temperature ◽  
Cutting Conditions ◽  
Cutting Condition ◽  
Nose Radius ◽  
Dry Cutting ◽  
Cnc Turning ◽  
Coated Carbide

This paper presents the additional work of the previous research in order to verify the previously obtained cutting condition by using the different cutting tool geometries. The effects of the cutting conditions with the dry cutting are monitored to obtain the proper cutting condition for the plain carbon steel with the coated carbide tool based on the consideration of the surface roughness and the tool life. The dynamometer is employed and installed on the turret of CNC turning machine to measure the in-process cutting forces. The in-process cutting forces are used to analyze the cutting temperature, the tool wear and the surface roughness. The experimentally obtained results show that the surface roughness and the tool wear can be well explained by the in-process cutting forces. Referring to the criteria, the experimentally obtained proper cutting condition is the same with the previous research except the rake angle and the tool nose radius.

scholarly journals The columnar to equiaxed transition in the directional solidification of aluminum based multicomponent alloys

2015 ◽  
Vol 68 (1) ◽  
pp. 85-90 ◽  
Author(s):  
Otávio Lima Rocha ◽  
Laércio Gouvea Gomes ◽  
Daniel Joaquim Conceição Moutinho ◽  
Ivaldo Leão Ferreira ◽  
Amauri Garcia
Keyword(s):  
Cooling Rate ◽  
Tip Growth ◽  
Solute Concentration ◽  
Unidirectional Solidification ◽  
Unsteady State ◽  
Flow Conditions ◽  
Multicomponent Alloys ◽  
Vertical Solidification ◽  
Columnar To Equiaxed Transition ◽  
Si Content

In this work the columnar to equiaxed transition (CET) was experimentally investigated in the unidirectional solidification of three aluminum based multicomponent alloys (Al-nSi-3Cu), with "n" equal to 5.5, 7.5 and 9 wt.%. The main parameters analyzed include the tip temperature gradient (GL), tip growth rate (VL), tip cooling rate (TR) and Si content. A water-cooled solidification experimental setup was developed, and specimens were solidified under unsteady state heat flow conditions. It is shown that for the alloys examined, the solute concentration influences the position of the CET, which occurs for an average cooling rate of about 1.17 0C/s. A comparative analysis between the results of this work and those from literature proposed to analyze the CET during upward vertical solidification of Al-Si alloys is reported and the results show that the end of the columnar region is abbreviated as a result of seven times higher critical cooling rate than that verified for Al-Si alloys.

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