Influence of Tempering Temperature in Wear of AISI T15 HSS Tools Produced by HIP and Liquid Phase Vacuum Sintering

2010 ◽  
Vol 1276 ◽  
Author(s):  
Emmanuel P. R. Lima ◽  
Maurício D. M. das Neves ◽  
Sérgio Delijaicov ◽  
Francisco A. Filho
Keyword(s):  
Liquid Phase ◽  
Electrical Discharge Machining ◽  
Rupture Strength ◽  
Hot Isostatic Pressing ◽  
Steel Plates ◽  
Machining Process ◽  
Vacuum Sintering ◽  
Tempering Temperature ◽  
Tools Wear ◽  
1045 Steel

AbstractThis work aims to investigate the influence of tempering temperature in the wear resistance of AISI T15 HSS tools produced by two different sintering processes – hot isostatic pressing (HIP) and liquid phase vacuum sintering. All materials are submitted to annealing at 870°C, quenching at 1210°C and triple tempering at 540, 550 and 560 °C. Density measurements, hardness and bend strength (transversal rupture strength – TRS) tests are accomplished. To identify the present phases and to evaluate the obtained microstructures, analysis in optical microscopy, SEM and EDX are done. Interchangeable inserts are manufactured by electrical discharge machining process. Frontal machining without coolant of normalized AISI 1045 steel plates is employed. The cutting forces are monitored via a transducer basically constituted of an instrumented table with four load cells mounted with “Strain Gages” sensors capable to measure the cutting efforts. The tools wear is analyzed and used to estimate the performance of two different HSS tools. For both investigated materials, the tools tempered at 540 °C show the lowest wearing.

Influences of Ball-Milled Time on Properties and Microstructure of Ultrafine WC-10Co Cemented Carbide

2007 ◽  
Vol 121-123 ◽  
pp. 1337-1340
Author(s):  
Xiao Liang Shi ◽  
Gang Qin Shao ◽  
Xing Long Duan
Keyword(s):  
Milling Time ◽  
Rupture Strength ◽  
Hot Isostatic Pressing ◽  
Cemented Carbide ◽  
Cemented Carbides ◽  
Vacuum Sintering ◽  
Average Grain Size ◽  
Fine Microstructure ◽  
Nanocomposite Powders ◽  
Ball Milling Time

WC-10Co nanocomposite powders prepared by spray pyrogenation-continuous reduction and carburization technology were consolidated by vacuum sintering plus hot isostatic pressing (HIP). Influences of ball-milled time on properties and microstructure of ultrafine WC-10Co cemented carbide were investigated. The results show that ultrafine WC-10Co cemented carbides can reach 99.79% relative density, and transverse rupture strength is more than 3750MPa, Rockwell A hardness is more than 92.6, the average grain size is less than 440 nm, when ball-milled time is 48 hours, ultrafine WC-10Co cemented carbide with excellent properties and fine microstructure is obtained. The optimum ball-milling time is 48 hours.

Influences of Ball-Milled Time on Properties and Microstructure of Ultrafine WC-10Co Cemented Carbide

2007 ◽  
Vol 121-123 ◽  
pp. 159-162
Author(s):  
Xiao Liang Shi ◽  
Gang Qin Shao ◽  
Xing Long Duan
Keyword(s):  
Milling Time ◽  
Rupture Strength ◽  
Hot Isostatic Pressing ◽  
Cemented Carbide ◽  
Cemented Carbides ◽  
Vacuum Sintering ◽  
Average Grain Size ◽  
Fine Microstructure ◽  
Nanocomposite Powders ◽  
Ball Milling Time

WC-10Co nanocomposite powders prepared by spray pyrogenation-continuous reduction and carburization technology were consolidated by vacuum sintering plus hot isostatic pressing (HIP). Influences of ball-milled time on properties and microstructure of ultrafine WC-10Co cemented carbide were investigated. The results show that ultrafine WC-10Co cemented carbides can reach 99.79% relative density, and transverse rupture strength is more than 3750MPa, Rockwell A hardness is more than 92.6, the average grain size is less than 440 nm, when ball-milled time is 48 hours, ultrafine WC-10Co cemented carbide with excellent properties and fine microstructure is obtained. The optimum ball-milling time is 48 hours.

RESEARCH ON SHAPING TECHNOLOGY OF NANOCOMPOSITE WC-6Co POWDER AND PROPERTIES OF SINTERED COMPACTS

2006 ◽  
Vol 05 (02n03) ◽  
pp. 233-238 ◽  
Author(s):  
XIAOLIANG SHI ◽  
GANGQIN SHAO ◽  
XINGLONG DUAN ◽  
RUNZHANG YUAN
Keyword(s):  
Rupture Strength ◽  
Hot Isostatic Pressing ◽  
High Hardness ◽  
Cold Isostatic Pressing ◽  
Sintered Specimen ◽  
Volume Distribution ◽  
Vacuum Sintering ◽  
Transverse Rupture Strength ◽  
Isostatic Pressing ◽  
Die Pressing

The influences of powder extrusion molding (PEM), die pressing and cold isostatic pressing (CIP) on the green compacts and the sintered compacts of nanocrystalline WC-6 Co composite powder produced by spray pyrogenation-continuous reduction and carburization technology were researched. The results showed that the pore volume distribution, density and scanning electron microscopy (SEM) morphologies of fractured surface of powder extrusion molding or die pressing followed by the cold isostatic pressing consolidation green compacts were better than that of powder extrusion molding or die pressing. The green compacts were sintered by using vacuum sintering plus hot isostatic pressing (HIP), the sintered specimens were characterized by testing density, Rockwell A hardness, saturated magnetization, coercivity force, transverse rupture strength (TRS) and atomic force microscope (AFM) images, the results showed that sintered specimen of the green body that prepared by powder extrusion molding or die pressing followed by cold isostatic pressing had excellent properties of high strength and high hardness, transverse rupture strength of sintered specimen was more than 3100 MPa, Rockwell A hardness of sintered body was more than 93. Ultrafine WC-6 Co cemented carbide rods with excellent mechanical properties and fine microstructure were obtained.

Optimization of μEDM process assisted with rotating magnetic pulling force and ultrasonic vibration

2021 ◽  
pp. 095440892098440
Author(s):  
Gurpreet Singh ◽  
DR Prajapati ◽  
PS Satsangi
Keyword(s):  
Ultrasonic Vibration ◽  
Material Removal Rate ◽  
Electrical Discharge ◽  
Material Removal ◽  
Electrical Discharge Machining ◽  
Removal Rate ◽  
Machining Process ◽  
Micro Electrical Discharge Machining ◽  
Pulling Force ◽  
Tool Rotation

The micro-electrical discharge machining process is hindered by low material removal rate and low surface quality, which bound its capability. The assistance of ultrasonic vibration and magnetic pulling force in micro-electrical discharge machining helps to overcome this limitation and increase the stability of the machining process. In the present research, an attempt has been made on Taguchi based GRA optimization for µEDM assisted with ultrasonic vibration and magnetic pulling force while µEDM of SKD-5 die steel with the tubular copper electrode. The process parameters such as ultrasonic vibration, magnetic pulling force, tool rotation, energy and feed rate have been chosen as process variables. Material removal rate and taper of the feature have been selected as response measures. From the experimental study, it has been found that response output measures have been significantly improved by 18% as compared to non assisted µEDM. The best optimal combination of input parameters for improved performance measures were recorded as machining with ultrasonic vibration (U1), 0.25 kgf of magnetic pulling force (M1), 600 rpm of tool rotation (R2), 3.38 mJ of energy (E3) and 1.5 mm/min of Tool feed rate (F3). The confirmation trail was also carried out for the validation of the results attained by Grey Relational Analysis and confirmed that there is a substantial improvement with both assistance applied simultaneously.

Experimental Study of Machining of Shape Memory Alloys Using Dry Micro Electrical Discharge Machining Process

2018 ◽  
Author(s):  
Sagil James ◽  
Sharadkumar Kakadiya
Keyword(s):  
Shape Memory Alloys ◽  
Shape Memory ◽  
Electrical Discharge ◽  
Material Removal ◽  
Electrical Discharge Machining ◽  
Removal Rate ◽  
Dielectric Medium ◽  
Machining Process ◽  
Machining Processes ◽  
Micro Electrical Discharge Machining

Shape Memory Alloys are smart materials that tend to remember and return to its original shape when subjected to deformation. These materials find numerous applications in robotics, automotive and biomedical industries. Micromachining of SMAs is often a considerable challenge using conventional machining processes. Micro-Electrical Discharge Machining is a combination of thermal and electrical processes, which can machine any electrically conductive material at micron scale independent of its hardness. It employs dielectric medium such as hydrocarbon oils, deionized water, and kerosene. Using liquid dielectrics has adverse effects on the machined surface causing cracking, white layer deposition, and irregular surface finish. These limitations can be minimized by using a dry dielectric medium such as air or nitrogen gas. This research involves the experimental study of micromachining of Shape Memory Alloys using dry Micro-Electrical Discharge Machining process. The study considers the effect of critical process parameters including discharge voltage and discharge current on the material removal rate and the tool wear rate. A comparison study is performed between the Micro-Electrical Discharge Machining process with using the liquid as well as air as the dielectric medium. In this study, microcavities are successfully machined on shape memory alloys using dry Micro-Electrical Discharge Machining process. The study found that the dry Micro-Electrical Discharge Machining produces a comparatively better surface finish, has lower tool wear and lesser material removal rate compared to the process using the liquid as the dielectric medium. The results of this research could extend the industrial applications of Micro Electrical Discharge Machining processes.

The Downsizing Effects in EDM Drilling of Micro Holes

2013 ◽  
Vol 549 ◽  
pp. 503-510 ◽  
Author(s):  
Gianluca D'Urso ◽  
Giancarlo Maccarini ◽  
C. Merla
Keyword(s):  
Electrical Discharge Machining ◽  
Steel Plates ◽  
Drilling Process ◽  
Micro Edm ◽  
Micro Electrical Discharge Machining ◽  
Micro Holes ◽  
Micro Drilling ◽  
Micro Features ◽  
Electron Microscopes ◽  
Manufacturing Technologies

The recent miniaturization trend in manufacturing, has enhanced the production of new and highly sophisticated systems in various industrial fields. In recent years, machining of the so called difficult to cut materials has become an important issue in several sectors. Micro Electrical Discharge Machining (micro-EDM) thanks to its contactless nature, is one of the most important technologies for the machining of this type of materials and it can be considered as one of the most promising manufacturing technologies for the fabrication of micro components. One of the most relevant applications of micro-EDM is micro-drilling. Micro holes in fact, are widely used for example in micro-electromechanical systems (MEMS), serving as channels or nozzles to connect two micro-features, and in micro-mechanical components. The present study is about micro drilling of metal plates by means of micro-EDM technology. In particular, the aim of this work is to investigate the effects of the downsizing of the micro holes diameter on the drilling performances. The influence of the reduction of the diameters in terms of both process performances (e.g., tool wear, taper rate, diametrical overcut) and general quality of the holes was investigated. Steel plates having thickness equal to 0.8 mm were taken into account. The drilling process was carried out using a micro-EDM machine Sarix SX 200 with carbide electrodes having diameter equal to 300, 200, 100 and 50 μm. Since the standard electrodes adopted in this study had a diameter equal to 300 μm, a wire EDM unit was used to obtain the other electrodes. The relationship between the process parameters considered the most significant and the final output, was studied. Furthermore, the geometrical and dimensional properties of the micro-holes were analyzed using both optical and scanning electron microscopes. In particular, it is demonstrated that the diameter size has a significant influence on the final value of the diametrical overcut while peak current and frequency parameters have a negligible effect.

scholarly journals Hybridization of Electrical Discharge Machining Process

2019 ◽  
Vol 9 (1) ◽  
pp. 1059-1065 ◽  
Keyword(s):  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Dielectric Medium ◽  
Machining Process ◽  
Hybrid Process ◽  
Machining Time ◽  
Expulsion Rate ◽  
Recent Developments ◽  
The Individual ◽  
Process Complexity

: This paper discusses the recent developments in the field of Electrical Discharge Machining (EDM) hybrid process. Spark machining is a universally recognised unconventional process, excluding the restriction of having low machining efficiency. To overcome this, various investigations have been made on designing of electrode, types of dielectric medium, variations in input parameters etc. Although material expulsion rate have been found to improve, nonetheless it cannot encounter the requirements of modern industries and the quality of surface is inferior. To increase further the utility of EDM, its hybridization with other process have to be carried out. A hybrid process can reduce the machining time while maintaining better surface and material expulsion rate. In hybrid process, the mechanism of two processes is applied concurrently or consecutively. Although, the performance of combined process is better as compared to the individual processes but hybridization increases the process complexity.

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