scholarly journals Final Heat Treatment as a Possible Solution for the Improvement of Machinability of Pb-Free Brass Alloys

Metals ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 575 ◽  
Author(s):  
Anagnostis Toulfatzis ◽  
George Pantazopoulos ◽  
Constantine David ◽  
Dimitrios Sagris ◽  
Alkiviadis Paipetis
Keyword(s):  
Heat Treatment ◽  
Surface Roughness ◽  
Power Consumption ◽  
Chip Morphology ◽  
Lead Free ◽  
Maximum Height ◽  
Average Roughness ◽  
Treatment Conditions ◽  
Order Of Magnitude ◽  
Brass Alloys

Heat treatment was performed in order to improve the machinability of three lead-free extruded and drawn brasses, namely CuZn42 (CW510L), CuZn38As (CW511L), and CuZn36 (C27450), based on the concept of microstructural modification. The examined machinability criteria were the following: chip morphology, power consumption, cutting force, and surface roughness. All the above quality characteristics were studied in turning mode in “as received” and “heat treated” conditions for comparison purposes. The selected heat treatment conditions were set for CW510L (775 °C for 60 min), CW511L (850 °C for 120 min), and C27450 (850 °C for 120 min) lead-free brass alloys, according to standard specification and customer requirement criteria. The results are very promising concerning the chip breaking performance, since the heat treatment contributed to the drastic improvement of chip morphology for every studied lead-free brass. Regarding power consumption, heat treatment seems beneficial only for the CW511L brass, where a reduction by 180 W (from 1600 to 1420 W), in relation to the as-received condition, was achieved. Furthermore, heat treatment resulted in a marginal reduction by 10 N and 15 N in cutting forces for CW510L (from 540 to 530 N) and CW511L (from 446 to 431 N), respectively. Finally, surface roughness, expressed in terms of the average roughness value (Ra), seems that it is not affected by heat treatment, as it remains almost at the same order of magnitude. On the contrary, there is a significant improvement of maximum height (Rt) value of CW511L brass by 14.1 μm (from 40.1 to 26.0 μm), after heat treatment process performed at 850 °C for 120 min.

Comparative investigations of cryo-treated and untreated inserts on machinability of AISI 1050 by using response surface methodology, ANOVA and Taguchi design

2021 ◽  
pp. 095440622110231
Author(s):  
Şehmus Baday ◽  
Onur Ersöz
Keyword(s):  
Heat Treatment ◽  
Surface Roughness ◽  
Response Surface Methodology ◽  
Cutting Force ◽  
Treatment Condition ◽  
Chip Morphology ◽  
Cutting Parameters ◽  
Heat Treatment Condition ◽  
Mixed Design ◽  
Treatment Conditions

This study aims to focus on the machinability of the AISI 1050 workpieces with cutting inserts, treated under deep cryogenic heat (−146 °C), and with untreated ones, and to investigate the optimization of cutting parameters and heat treatment conditions for surface roughness and cutting force by using Taguchi mixed design and Response Surface Methodology (RSM). The machining experiment was performed on a CNC lathe with machining parameters such as three feed rates, three cutting speeds and a constant depth of cut under dry condition and with heat treatment condition. As is known, Taguchi design L18 (32 21) consists of three factors; cutting parameters with each one of three levels and heat treatment condition with two levels. The results of machining tests were evaluated considering surface roughness, vibrations and cutting force. Furthermore, chip morphology and wear led by cryo-treated and untreated inserts were detected with the aid of a scanning electron microscope. The results demonstrated that cryo-treated (CTI) insert had lower tool wear, vibration, and cutting force than untreated insert (UI) in all conditions. In aspect of chip morphology, untreated inserts had bigger and larger serrations than the treated inserts. In addition, according to Taguchi S/N ratio, optimal cutting parameters and heat treatment conditions were obtained from CHT1, V3, and f1 for the Fc and from CHT1, V1, and f1 for the Ra, respectively. Also, the most significant control factors on surface roughness and cutting force were feed rate depending on ANOVA results and RSM. Validation test results demonstrated that RSM and Taguchi mixed design calculated the cutting force (R2RSM (CTI and UI) = 99.99% and R2Tag. = 99.95%) and surface roughness (R2RSM (CTI) = 99.76%, R2RSM (UI) = 99.59% and R2Tag. = 99.12%). Therefore, RSM and Taguchi mixed design predicts highly well match experimental data with prediction data.

Effect of Heat Treatment Conditions on Properties of Lead‐Free Bi2GeO5 Ferroelectric Glass Ceramics

2009 ◽  
Author(s):  
P. Kantha ◽  
K. Pengpat ◽  
G. Rujijanagul ◽  
T. Tunkasiri ◽  
S. Eitssayeam ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Glass Ceramics ◽  
Lead Free ◽  
Treatment Conditions

Effect of lead on the machinability of brass alloys using polycrystalline diamond cutting tools

2018 ◽  
Vol 53 (8) ◽  
pp. 602-615 ◽  
Author(s):  
Luis Amaral ◽  
Rafael Quinta ◽  
Tiago E Silva ◽  
Rui MB Soares ◽  
Santiago D Castellanos ◽  
...  
Keyword(s):  
Tool Wear ◽  
Cutting Forces ◽  
Cutting Tools ◽  
Polycrystalline Diamond ◽  
Chip Morphology ◽  
Lead Free ◽  
Production Techniques ◽  
Polycrystalline Diamond Inserts ◽  
Brass Alloys

The international safety regulations are pushing the manufacturers of water systems and equipment to remove lead from material compositions due to the potential human hazard of lead absorption. The usage of green lead-free brass alloys is becoming mandatory in many important markets, demanding the manufacturers to quickly adapt their production techniques both casting and machining to this new reality. Regarding machining, lead has been used to facilitate the chip control, working as a natural chip breaker and reducing the tool wear. Therefore, the reduction of lead composition in brass alloys contributes to a machinability decrease of the materials leading to higher cutting forces, long chips and higher tool wear. This work focuses on the machinability characterization of three different brass alloys (leaded, medium-leaded and minimally leaded) by means of cylindrical external turning process with polycrystalline diamond inserts. A parametric study covering three different depths of cuts, three feed rates and four cutting speeds was conducted for three brass alloys with two repetitions. Cutting forces, chip morphology and surface roughness were analysed and compared between alloys. Complementary microstructural and mechanical characterization of the alloys were performed. Analysis of variance was performed to analyse the results. Cutting forces, power consumption, specific cutting pressure, roughness and chip morphology identification were used as comparison criteria among the tested materials. Results have demonstrated the decrease of machinability with the lead reduction, with higher cutting forces and longer chips. Polycrystalline diamond tools used in this work could be a good option to overcome the machinability challenges of the lead-free brass alloys.

scholarly journals The Influence of Age Hardening and Shot Peening on the Surface Properties of 7075 Aluminium Alloy

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2220
Author(s):  
Sebastjan Žagar ◽  
Boštjan Markoli ◽  
Iztok Naglič ◽  
Roman Šturm
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Solid Solution ◽  
Surface Roughness ◽  
Residual Stresses ◽  
Shot Peening ◽  
Alloying Elements ◽  
Age Hardening ◽  
Treatment Conditions ◽  
Almen Intensity

The present study investigates the effect of shot peening (SP) on the mechanical properties and surface roughness of 7075 aluminum alloy during different stages and conditions of heat treatment. The mechanical properties were determined by measuring Vickers microhardness profiles and residual stress profiles, while the amount of alloying elements present in the solid solution of the samples under different heat treatment conditions was determined by measuring the electrical conductivity. The results show that the increase in microhardness near the SP surface and the maximum compressive residual stresses are mainly related to the content of alloying elements in the solid solution. Surface roughness increases with increasing SP Almen intensity, and samples with the highest microhardness and residual stresses have the lowest surface roughness.

scholarly journals Machinability of Eco-Friendly Lead-Free Brass Alloys: Cutting-Force and Surface-Roughness Optimization

Metals ◽  
2018 ◽  
Vol 8 (4) ◽  
pp. 250 ◽  
Author(s):  
Anagnostis Toulfatzis ◽  
George Pantazopoulos ◽  
Constantine David ◽  
Dimitrios Sagris ◽  
Alkiviadis Paipetis
Keyword(s):  
Surface Roughness ◽  
Cutting Force ◽  
Lead Free ◽  
Brass Alloys

INFLUENCE THE QUENCHING AND TEMPERING ON THE MICROSTRUCTURE, MECHANICAL PROPERTIES AND SURFACE ROUGHNESS, OF MEDIUM CARBON STEEL

2018 ◽  
Vol 18 (1) ◽  
pp. 125-135
Author(s):  
Sattar H A Alfatlawi
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Surface Roughness ◽  
Carbon Steel ◽  
Cold Water ◽  
Medium Carbon Steel ◽  
Medium Carbon ◽  
Heating And Cooling ◽  
Treatment Processes ◽  
Quenching And Tempering

One of ways to improve properties of materials without changing the product shape toobtain the desired engineering applications is heating and cooling under effect of controlledsequence of heat treatment. The main aim of this study was to investigate the effect ofheating and cooling on the surface roughness, microstructure and some selected propertiessuch as the hardness and impact strength of Medium Carbon Steel which treated at differenttypes of heat treatment processes. Heat treatment achieved in this work was respectively,heating, quenching and tempering. The specimens were heated to 850°C and left for 45minutes inside the furnace as a holding time at that temperature, then quenching process wasperformed in four types of quenching media (still air, cold water (2°C), oil and polymersolution), respectively. Thereafter, the samples were tempered at 200°C, 400°C, and 600°Cwith one hour as a soaking time for each temperature, then were all cooled by still air. Whenthe heat treatment process was completed, the surface roughness, hardness, impact strengthand microstructure tests were performed. The results showed a change and clearimprovement of surface roughness, mechanical properties and microstructure afterquenching was achieved, as well as the change that took place due to the increasingtoughness and ductility by reducing of brittleness of samples.

On the defects of enamel coatings

2019 ◽  
pp. 145-150
Author(s):  
T. O. Soshina ◽  
V. R. Mukhamadyarovа
Keyword(s):  
Heat Treatment ◽  
Surface Tension ◽  
Electron Microscope ◽  
Enamel Coating ◽  
Surface Defects ◽  
Linear Expansion ◽  
Corrosion Properties ◽  
Treatment Conditions ◽  
Mechanical And Corrosion Properties ◽  
Coefficient Of Linear Expansion

The defects destroy the integrity of the enamel, and the paper examines the influence of the physical-mechanical and corrosion properties of frits and heat treatment on the defectiveness of the enamel coating. The surface defects were scanned by electron microscope. It has been established that the defectiveness of enamel coatings depends on the melting index, temperature coefficient of linear expansion, surface tension of the frits, and heat treatment conditions. When burning rate of the enamel coating decreases, the fine-meshed structure of the enamel changes, and the size of the defects decreases.

scholarly journals Heat Treatment Evaluation for the Camshafts Production of ADI Low Alloyed with Vanadium

Metals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1036
Author(s):  
Eduardo Colin García ◽  
Alejandro Cruz Ramírez ◽  
Guillermo Reyes Castellanos ◽  
José Federico Chávez Alcalá ◽  
Jaime Téllez Ramírez ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Tensile Strength ◽  
Ductile Iron ◽  
Volume Fraction ◽  
Energy Impact ◽  
Treatment Conditions ◽  
Mold Casting ◽  
Grade 3 ◽  
Good Agreement

Ductile iron camshafts low alloyed with 0.2 and 0.3 wt % vanadium were produced by one of the largest manufacturers of the ductile iron camshafts in México “ARBOMEX S.A de C.V” by a phenolic urethane no-bake sand mold casting method. During functioning, camshafts are subject to bending and torsional stresses, and the lobe surfaces are highly loaded. Thus, high toughness and wear resistance are essential for this component. In this work, two austempering ductile iron heat treatments were evaluated to increase the mechanical properties of tensile strength, hardness, and toughness of the ductile iron camshaft low alloyed with vanadium. The austempering process was held at 265 and 305 °C and austempering times of 30, 60, 90, and 120 min. The volume fraction of high-carbon austenite was determined for the heat treatment conditions by XRD measurements. The ausferritic matrix was determined in 90 min for both austempering temperatures, having a good agreement with the microstructural and hardness evolution as the austempering time increased. The mechanical properties of tensile strength, hardness, and toughness were evaluated from samples obtained from the camshaft and the standard Keel block. The highest mechanical properties were obtained for the austempering heat treatment of 265 °C for 90 min for the ADI containing 0.3 wt % V. The tensile and yield strength were 1200 and 1051 MPa, respectively, while the hardness and the energy impact values were of 47 HRC and 26 J; these values are in the range expected for an ADI grade 3.

scholarly journals Effect of Optical and Morphological Control of Single-Structured LEC Device

Micromachines ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 843
Author(s):  
Woo Jin Jeong ◽  
Jong Ik Lee ◽  
Hee Jung Kwak ◽  
Jae Min Jeon ◽  
Dong Yeol Shin ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Surface Roughness ◽  
Surface Properties ◽  
High Efficiency ◽  
High Surface ◽  
Reduction Rate ◽  
Operating Characteristics ◽  
Emission Layer ◽  
Light Emitting ◽  
Stable Operating

We investigated the performance of single-structured light-emitting electrochemical cell (LEC) devices with Ru(bpy)3(PF6)2 polymer composite as an emission layer by controlling thickness and heat treatment. When the thickness was smaller than 120–150 nm, the device performance decreased because of the low optical properties and non-dense surface properties. On the other hand, when the thickness was over than 150 nm, the device had too high surface roughness, resulting in high-efficiency roll-off and poor device stability. With 150 nm thickness, the absorbance increased, and the surface roughness was low and dense, resulting in increased device characteristics and better stability. The heat treatment effect further improved the surface properties, thus improving the device characteristics. In particular, the external quantum efficiency (EQE) reduction rate was shallow at 100 °C, which indicates that the LEC device has stable operating characteristics. The LEC device exhibited a maximum luminance of 3532 cd/m2 and an EQE of 1.14% under 150 nm thickness and 100 °C heat treatment.

PERFECT case studies demonstrating order of magnitude reduction in power consumption

2016 ◽  
Author(s):  
David K. Wittenberg ◽  
Edin Kadric ◽  
Andre DeHon ◽  
Jonathan Edwards ◽  
Jeffrey Smith ◽  
...  
Keyword(s):  
Power Consumption ◽  
Case Studies ◽  
Order Of Magnitude
Sign in / Sign up

Export Citation Format

Share Document