Thermal Analyses for Induction Sintering of Powder Metal Compacts up to Sintering Temperature

Induction sintering is developed as an alternative method to conventional sintering in order to sinter iron-based powder metal (PM) compacts. In this study, the 12 kW power and 30 kHz frequency induction-sintering machine is used for 3 wt.% copper-mixed iron. The effects of different shapes and sizes of the induction coil, and temperature differences on the PM compacts up to sintering temperature are investigated; these parameters are determined both theoretically and experimentally during induction sintering. Iron-based PM compacts are sintered at 1120°C. Induction sintering of iron-based PM compacts are simulated using a program to examine the effects of magnetic flux and temperature distribution in the sample over time. The results are compared with the experimental studies.Индукционное спекание было разработано как альтернатива обычному спеканию, чтобы спекать прессовки порошковых материалов (ПМ) на основе железа. В данной работе использована индукционная агломерационная машина мощностью 12 кВт и частотой 30 кГц для спекания смеси железа с 3 масс.% меди. Исследованы влияния различных форм и размеров индукционных катушек, разниц температур на брикеты ПМ вплоть до температуры спекания; эти параметры были исследованы как теоретически, так и экспериментально во время индукционного спекания. Брикеты ПМ на основе железа спекались при 1120°C. Индукционное спекание брикетов ПМ на основе железа также смоделировано с использованием программы, которая исследует влияние магнитного потока и распределения температуры в образце со временем. Результаты сопоставлены с результатами экспериментальных исследований.Індукційне спікання було розроблено як альтернатива звичайному спіканню, щоб спікати брикети порошкових матеріялів (ПМ) на основі заліза. В даній роботі використано індукційну аґломераційну машину потужністю у 12 кВт і частотою у 30кГц для спікання суміші заліза з 3 ваг.% міді. Досліджено впливи різних форм і розмірів індукційної шпулі, ріжниць температур на брикети ПМ аж до температури спікання; ті параметри було досліджено як теоретично, так й експериментально під час індукційного спікання. Брикети ПМ на основі заліза спікалися при 1120°C. Індукційне спікання брикетів ПМ на основі заліза також модельовано з використанням програми, яка досліджує впливи магнетного потоку та розподілу температури у зразку з часом. Результати порівняно з результатами експериментальних досліджень

The Effect of Sintering on the Microstructure, Hardness, and Tribological Behavior of Aluminum–Graphene Nanoplatelet Powder Composites

In this study, aluminum and graphene nanoplatelet (GNP) powders were mixed in different ratios and sintered by the conventional method. The powder mixtures were stirred for 2 h at a speed of 35 rpm in a V-type mixer to obtain a homogeneous dispersion. The nanocomposite powder mixtures were pressed by the CIP (Cold Isostatic Pressing) method at a pressure of 400 MPa. Sintering was carried out at 620°C for 1 h under argon gas. The density, surface roughness, weight loss, and Vickers hardness of the nanocomposites were evaluated. SEM, EDX, and XRD analyses were performed and the obtained results were examined. The effect of the graphene addition to aluminum was evaluated, and the optimum contribution of 0.8 wt.% GNP has been determined. © 2018, Springer Science+Business Media, LLC, part of Springer Nature

A study of soil tillage tools from boronized sintered iron

Acomparative analysis of the properties of boronized sintered iron and quenched steels 30MnB5, 28MnCrB5 used for making soil tillage tools is performed. The microstructure, phase composition, hardness and strength characteristics of the materials are studied. The composition of the boride phase formed in the sintered iron after boronizing is determined by an x-ray method. The losses to abrasive wear are evaluated with the help of a device containing a special bin with a sample of abrasive soil. © 2017 Springer Science + Business Media New York

Effects of Coil Design on Induction Welding of Sintered Iron Based Compacts

Sintered iron based compacts were welded by applying a high frequency induction process. The cross-sections of the compacts were square in shape so two different coil shapes, cylindrical and square, were studied with respect to the effect of magnetic flux. The effect of welding duration on the macrostructural changes and mechanical properties of the induction welded compacts were investigated for welding durations of 3, 5 and 10 minutes

Cost analysis of T6 induction heat treatment for the aluminum-copper powder metal compacts

This work compares an energy cost and an energy consumption results of the 4 wt.% cupper mixed aluminum based powder metal (PM) compacts processing under induction or furnace heating. Total power and energy consumptions and total energy costs per kilogram and compact have been analyzed. T6 precipitation heat treatment applications have been applied with two different methods, one with 2.8 kW, 900 kHz ultra-high frequency induction heating system (UHFIHS), other with 2 kW chamber furnace. In the first method, Al-Cu PM compacts have been heated by induction at 580 °C in one minute and then cooled down by water. Afterwards, the samples have been heated 170, 180, 190 and 200 °C respectively for artificial ageing and cooled naturally. In the second treatment, unlike the first study, Al-Cu PM compacts are heated by chamber furnace at 540 °C in 5 hours and cooled by water. Then PM compacts are artificially aged at 190 °C in 10 hours with same furnace. During both processes, energy and power consumptions for each defined process have been measured. Optimum heat treatment of the induction is determined. The cheaper energy cost is obtained by the induction heat treatment. © 2020 Authors. Published by association for ETRAN Society

The mechanical and tribological characteristic of Aluminium-Titanium dioxide composites

The purpose of this work was to investigate the mechanical and tribological effects of Titanium dioxide (TiO2) reinforcement in Aluminium (Al). Aluminium composites consist of 99.8% pure aluminium reinforced with five different partions of TiO2. Aluminium powders were mixed with TiO2 by ball milling for 30 minutes in a planetary mixer. The powder mixture was compacted by the cold pressing technique at 250 MPa. Two different methods used for sintering. The green compact was sintered at 600 °C for 300 seconds in open atmosphere with an Ulta-High Frequency Induction System (UHFIS) and with furnace at 600 °C for 1800 seconds. The mechanical and microstructural properties of examples were compared for different amount of reinforcement. We have observed a maximum hardness for 5 wt.% TiO2 reinforced composites. © 2018 CSIC

In-situ compaction and sintering of Al2O3-B4C composites by using a High-Frequency Induction System

Alumina powders containing varying ratios of B4C were mixed in a V-type mixer for 30 min with 35 cycle/min to obtain a homogeneous mixture. Six different chemical compositions were prepared and sintered at 1600°C for 20 min using an Ultra-High-Frequency Induction Heated System. The samples were cooled by air. The density, surface roughness, hardness and microstructure of samples were investigated. The results showed that when the amount of B4C increased, the values of hardness increased and the values of surface roughness decreased. © 2018 Institute of Materials and Machine Mechanics, Slovak Academy of Sciences. All rights reserved