Indian Institute of Technology Palakkad&nbsp;(IIT Palakkad or IIT PKD) is a public autonomous&nbsp;engineering&nbsp;and&nbsp;research&nbsp;institute located in&nbsp;Palakkad,&nbsp;Kerala. It was&nbsp;one of the five new&nbsp;IITs&nbsp;proposed in the&nbsp;2014 Union budget of India. The campus was inaugurated on 3 August 2015. The institute has 94 faculty, 978 students, and 63 non-teaching staffs.

IT Palakkad currently offers four-year Bachelor of Technology (B.Tech) and two years MS programmes in 8 different engineering disciplines including&nbsp;Computer Science, Electrical, Mechanical, Civil among others.

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IIT Palakkad

Haynes 282 is a creep-resistant, γ′ strengthened nickel-based superalloy with excellent weldability. Additive manufacturing, especially laser powder bed fusion (LPBF), of Haynes 282 is being researched for its potential applications in aerospace and power generation sectors. LPBF enables us to achieve desired properties via microstructure control through process parameter optimization. Integrated computational materials engineering (ICME) approach can be used to tune the process parameters to obtain desired microstructure, instead of trial-and-error methods. In this report, ICME framework has been established to simulate microstructural evolution during LPBF and post-processing of Haynes 282. A dimensionless number was used to optimize the process parameters with minimal porosity. Thermal modelling was performed using a semi-analytical model and the obtained thermal data was used to simulate solidification during LPBF. The corresponding cell spacing obtained matched closely with the experimental data. The segregation pattern extracted from the phase-field model was used as input for homogenization simulation. The γ′ precipitate evolution was predicted using Langer–Schwartz theory and Kampmann–Wagner-Numerical (KWN) approach. The predicted values agreed with the experimentally measured values. The room temperature yield strength of as-built samples was comparable and that of heat-treated samples were superior to the aged wrought material.

World University root node

Department of Mechanical Engineering

Journal of Materials Science

ICME framework to simulate microstructure evolution during laser powder bed fusion of Haynes 282 nickel-based superalloy

Engineering components can be subjected to normal and/or rotational fretting wear with contacts that are intermittently exposed to the atmosphere. Exposure to the environment may lead to the alteration at the contact due to the changing role of third body particles such as hard oxides which can result in abrasion. The abrasion due to hard oxide particles differs for the closed contact and intermittently opened contact. In the former scenario, the oxides are compacted into tribo-film, while in the latter case they remain loose, leading to bigger role of abrasion. Standard fretting test setup employed to estimate the fretting wear characteristic operates with a constant load such that the contact remains closed between the counter surfaces and does not simulate the opening and closing of the contacts as observed in certain applications. The forceful interruptions to the experiments to simulate open and close condition of the contact require considerable amount of time and effort. In this paper, an accelerated test procedure is proposed and investigated to capture the effect of intermittent opening of the contact without stopping the experiments. A test rig is designed to simulate the opening and closing conditions, and tests were performed with abrasive diamond-like particles. Friction and wear results are compared with those of intermittently contact opening conditions along with operating wear mechanisms. Scanning electron microscope analysis showed that the wear mechanism observed in the case of fretting with intermittent opening of contact is similar to that of fretting with diamond-like abrasives at the contact. © 2017, Springer Science+Business Media, LLC.

Tribology Letters

Accelerated Fretting Wear Tests for Contacts Exposed to Atmosphere

Many numerical models are proposed in the literature using finite element and finite discrete element methods to study fretting wear, barely including the effect of wear debris. These models being computationally expensive, simulating large number of fretting wear cycles is not practically feasible. A new methodology is proposed which needs only bulk material properties like friction/wear coefficients and uses semi-analytical methods to simulate fretting wear with entrapped debris. In this approach, debris are assumed to be attached to one of the surfaces during the fretting process. The results obtained from this approach were compared with fretting experiments. The proposed method permits to capture the wear depth and scar width, and results are very close to that observed in the experiments. © 2016 Elsevier Ltd

Tribology International

Semi analytical fretting wear simulation including wear debris

IC Engine valve components are generally made from Nickel based (Nimonic-80A) super alloys and these components are exposed to severe operating conditions while the engine is running. Interface fretting combined with impact wear causes major wear related failures to the valve and seat components. There is a need to predict wear of such interfaces so that their life and residual life (i.e. inspection) can be assessed. This paper focusses on a fretting wear of Nimonic-80A material line contact (cylinder-on-flat) at both room temperature and at high temperature conditions. The objective of this study is also to be able to understand the effect of interface fretting displacement, which is the key parameter that controls wear. Tests were performed at three different displacement amplitudes at room temperature (RT) and at high temperature (620°C) for 25,000 cycles. Experimental constants such as wear coefficient (k) and friction coefficient (µ) were derived from the test results. The wear and friction coefficients were then used in the wear-model to predict the wear depth. Further, this model was used to predict wear at 100,000 cycles. Predicted results are compared then with results from tests which have been run beyond 25,000 cycles (i.e. 100,000 cycles). © 2016 Elsevier Ltd

High temperature fretting wear prediction of exhaust valve material

An important metallurgical difficulty in arc welding of high-strength aluminum alloys is formation of solidification cracking. In this work, an attempt is made to reduce the solidification cracking in welding of aluminum alloys through vibratory treatment. The material used for the investigation is AA2014 aluminum alloy, which is highly prone to solidification cracking. Vibratory treatment was carried out in the frequency range of 100 Hz to 3700 Hz. Weldments made with and without vibratory treatment were compared using weld cracking tests and other characterization tests such as microstructural analysis. The test results show that by applying vibratory treatment, solidification cracking can be largely controlled in arc welding. © EDP Sciences, 2011.

Revue de Metallurgie. Cahiers D'Informations Techniques

Studies on the effect of vibratory treatment on reduction of solidification cracking in AA2014 aluminum alloys

International Journal of Engineering Science and Technology

Studies on the effect of vibration on hot cracking and grain size in AA 7075 aluminum alloy welding

The nickel based Colmonoy 5 alloy powder was deposited on 316 L (N) austenitic stainless steel substrate. In order to examine the effects of aging treatment on the wear behavior of a nickel based hardfacing alloy, the as-deposited coating was aged at 580°C for 5000h in ambient atmosphere. Coating microstructures were characterised by scanning and transmission electron microscopy. Sliding tests were conducted under self mated condition at room temperature and 550°C using a pin-on disc type apparatus. The wear loss of the aged coating was found to be higher than that of the as deposited coating. The coarse grained structure with carbide (Cr23C6) precipitation in the aged coating would account for the higher sliding wear loss. However, the aged coating, with reduced hardness exhibits similar wear behavior of as deposited coating during sliding at 550°C. © (2011) Trans Tech Publications.

Advanced Materials Research

Effect of aging treatment on microstructure and wear behaviour of a nickel based hardfaced coating

In this work nickel based hardfacing alloy (Colmonoy 5) was deposited on 316L (N) stainless steel substrate to study the effects of aging treatment on coating microstructure, wear and corrosion properties. Coatings, deposited through plasma transferred arc (PTA) welding process, were aged at 923K for 5000h. Microstructural characterization studies carried out by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) revealed the coarsening of dendrites and precipitation of Cr23C6 particles in the aged coating. The wear behavior of the as deposited and aged coatings was compared in room temperature (RT) and high temperature (823K) under dry sliding wear condition (pin-on-disc configuration). At RT, aged coating experienced more wear loss when compared to as-deposited. At high temperature, the wear loss was almost same with similar operating wear mechanisms (tribo-oxidation) for both as-deposited and aged coating. From pitting corrosion studies, it was found that aged coatings are more prone to pitting when compared to the as-deposited coatings. © 2011 Elsevier B.V.

Wear

Influence of aging treatment on microstructure, wear and corrosion behavior of a nickel base hardfaced coating

In the present study, Ni-based Colmonoy 5 was deposited on Type 316L (N) stainless steel. The deposit was aged at 580 and 650°C for 5,000 h to study the influence of aging on sliding wear resistance. The aged deposits show more wear loss due to reduced hardness. However, the reduced hardness after aging was not reflected on wear test at 550°C irrespective of sliding distance. This is due to stability of microstructure as well as the generation of oxide layer during high temperature tests. Subsequently, an empirical relation was developed based on outcome experimental data using full factorial design of experiments in terms of hardness (H), test temperature (T) and sliding distance (D). Based on the empirical relation, it was found that the test temperatures (T) play a predominant role on wear loss than hardness (H) and sliding distance (D). Further, the developed relationships were validated using analysis of variance (ANOVA). © 2011 Indian Institute of Metals.

Transactions of the Indian Institute of Metals

A study on influence of aging treatment on sliding wear resistance of a nickel based hardfacing alloy

In the present study, influence of microstructure on high temperature dry sliding wear behavior of nickel base hardfaced coating is discussed in detail. Using plasma transferred arc (PTA) welding process, coating of nearly 4 to 5. mm thickness was deposited on 316 L (N) stainless steel substrate without any defects. The as-deposited coating contains large quantity of precipitates (range from 100nm to 20μm in size) in the γ-nickel matrix which increased the hardness significantly. Sliding wear tests were carried out on the coating for different sliding distances at room temperature (RT) and also higher temperature (573. K, and 823. K). Results showed that the wear resistance of coating improved significantly with increase in test temperature, and the high wear resistance was observed at 823. K. The coating exhibited different operating wear mechanisms depending on sliding distances and also test temperature. The wear mechanisms were identified based on friction and wear values along with worn surface analysis. The operating wear mechanisms at 823. K are adhesion at shorter sliding distance and tribo-oxidation at longer sliding distance. © 2010 Elsevier B.V.