scholarly journals Scratch Behaviour of Silicon Solid Solution Strengthened Ferritic Compacted Graphite Iron (CGI)

2018 ◽  
Vol 925 ◽  
pp. 318-325
Author(s):  
Rohollah Ghasemi ◽  
Anders E.W. Jarfors
Keyword(s):  
Solid Solution ◽  
Normal Load ◽  
Scratch Test ◽  
Scratch Resistance ◽  
Compacted Graphite Iron ◽  
Depth Of Penetration ◽  
Scratch Depth ◽  
Compacted Graphite ◽  
Diamond Indenter ◽  
Different Content

The present study focuses on scratch behaviour of a conventional pearlitic and a number of solid solution strengthened ferritic Compacted Graphite Iron (CGI) alloys. This was done by employing a single-pass microscratch test using a sphero-conical diamond indenter under different constant normal loads conditions. Matrix solution hardening was made by alloying with different content of Si alloy; (3.66, 4.09 and 4.59 wt%. Si) which are named as low-Si, medium-Si and high-Si ferritic CGI alloys, respectively. A good correlation between the tensile and scratch test results was observed explaining the influence of CGI’s matrix characteristics on scratch behaviour both for pearlitic and fully ferritic solution strengthened ones. Both the scratch depth and scratch width showed strong tendency to increase with increasing the normal load, however the pearlitic one showed more profound deformation compared to the solution strengthened CGI alloys. Among the investigated alloys, the maximum and minimum scratch resistance was observed for high-Si ferritic CGI and pearlitic alloys, respectively. It was confirmed by the scratched surfaces analysed using Scanning Electron Microscopy (SEM) as well. In addition, the indenter’s depth of penetration value (scratch depth) was found as a suitable measure to ascertain the scratch resistance of CGI alloys.Keywords: Silicon solution strengthening, CGI, Abrasion, Scratch testing, Scratch resistance

scholarly journals Scratch Testing of AlSi12/SiCp Composite Layer with High Share of Reinforcing Phase Formed in the Centrifugal Casting Process

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1685
Author(s):  
Anna Janina Dolata ◽  
Marek Mróz ◽  
Maciej Dyzia ◽  
Magdalena Jacek-Burek
Keyword(s):  
Simple Model ◽  
Abrasion Resistance ◽  
Centrifugal Casting ◽  
Composite Layer ◽  
Casting Process ◽  
Scratch Test ◽  
Scratch Testing ◽  
Scratch Depth ◽  
Diamond Indenter ◽  
High Share

The scratch test enables assessing the susceptibility of a material to the development of scratches and, being in some ways a measure of its abrasion resistance, allows extended knowledge in the field of material application usability, especially its machining capabilities. The aim of the study was to assess the resistance of a centrifugally formed AlSi12/SiCp composite layer with a high share of reinforcing phase (Vp > 40%) to scratching with a diamond indenter. The microstructure and effect of the load applied to the diamond indenter on the scratch depth and susceptibility of the composite layer to the nucleation and propagation of cracks in hard and brittle SiC particles were analyzed. A simple model of SiCp cracking depending on their size, shape (geometry), and orientation in relation to the direction of scratching has been proposed.

Evaluation of subsurface crack depth during scratch test for optical glass BK7

2011 ◽  
Vol 225 (12) ◽  
pp. 2767-2774 ◽  
Author(s):  
W Gu ◽  
Z Yao ◽  
K Li
Keyword(s):  
Optical Glass ◽  
Normal Load ◽  
Crack Depth ◽  
Scratch Test ◽  
Scratch Depth ◽  
Scratch Hardness ◽  
Deformation And Fracture ◽  
Constant Normal Load ◽  
Scratch Tests ◽  
Abrasive Process

To get insight into the deformation and fracture behavior of brittle materials during abrasive process, scratch tests with linearly increasing normal load and constant normal load were conducted on BK7 using Vickers indenters. The effect of the applied normal load on the characteristics of surface cracks as well as the square of the scratch depth was found insensitive to the two load conditions discussed here. By taking both scratch and residual depths into consideration, a model of scratch hardness for brittle material was developed. Based on this scratch hardness, the correlation between the depth of the subsurface cracks and the scratch depth was established and was found in general agreement with the experimental results.

scholarly journals Interfacial debonding in compacted graphite iron: effect of thermal loading

2020 ◽  
Vol 28 ◽  
pp. 1286-1294
Author(s):  
Evangelia Nektaria Palkanoglou ◽  
Konstantinos P. Baxevanakis ◽  
Vadim V. Silberschmidt
Keyword(s):  
Thermal Loading ◽  
Interfacial Debonding ◽  
Compacted Graphite Iron ◽  
Compacted Graphite

Effects of Mo and Ni on the thermal conductivity of compacted graphite iron at elevated temperature

2019 ◽  
Vol 32 (5-6) ◽  
pp. 243-251 ◽  
Author(s):  
Dongmei Xu ◽  
Guiquan Wang ◽  
Xiang Chen ◽  
Yanxiang Li ◽  
Yuan Liu ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Elevated Temperature ◽  
Compacted Graphite Iron ◽  
Compacted Graphite

Experimental and Three-Dimensional Finite Element Study of Scratch Test of Polymers at Large Deformations

2004 ◽  
Vol 126 (2) ◽  
pp. 372-379 ◽  
Author(s):  
J. L. Bucaille ◽  
E. Felder ◽  
G. Hochstetter
Keyword(s):  
Strain Hardening ◽  
Penetration Depth ◽  
Large Deformations ◽  
Numerical Study ◽  
Scratch Test ◽  
Scratch Resistance ◽  
Plastic Strains ◽  
Thermosetting Polymer ◽  
Scratch Tests ◽  
Hardening Coefficient

An experimental and numerical study of the scratch test on polymers near their surface is presented. The elastoplastic response of three polymers is compared during scratch tests at large deformations: polycarbonate, a thermosetting polymer and a sol-gel hard coating composed of a hybrid matrix (thermosetting polymer-mineral) reinforced with oxide nanoparticles. The experiments were performed using a nanoindenter with a conical diamond tip having an included angle of 30 deg and a spherical radius of 600 nm. The observations obtained revealed that thermosetting polymers have a larger elastic recovery and a higher hardness than polycarbonate. The origin of this difference in scratch resistance was investigated with numerical modelling of the scratch test in three dimensions. Starting from results obtained by Bucaille (J. Mat. Sci., 37, pp. 3999–4011, 2002) using an inverse analysis of the indentation test, the mechanical behavior of polymers is modeled with Young’s modulus for the elastic part and with the G’sell-Jonas’ law with an exponential strain hardening for the viscoplastic part. The strain hardening coefficient is the main characteristic parameter differentiating the three studied polymers. Its value is equal to 0.5, 4.5, and 35, for polycarbonate, the thermosetting polymer and the reinforced thermosetting polymer, respectively. Firstly, simulations reveals that plastic strains are higher in scratch tests than in indentation tests, and that the magnitude of the plastic strains decreases as the strain hardening increases. For scratching on polycarbonate and for a penetration depth of 0.5 μm of the indenter mentioned above, the representative strain is equal to 124%. Secondly, in agreement with experimental results, numerical modeling shows that an increase in the strain hardening coefficient reduces the penetration depth of the indenter into the material and decreases the depth of the residual groove, which means an improvement in the scratch resistance.

Cutting Tool Wear and Mechanisms of Chip Formation During High-Speed Machining of Compacted Graphite Iron

2007 ◽  
Author(s):  
Niniza S. P. Dlamini ◽  
Iakovos Sigalas ◽  
Andreas Koursaris
Keyword(s):  
Tool Wear ◽  
Surface Finish ◽  
Failure Criterion ◽  
Cutting Tool ◽  
Flank Wear ◽  
Cutting Tools ◽  
Compacted Graphite Iron ◽  
Crater Wear ◽  
Compacted Graphite ◽  
Cutting Speeds

Cutting tool wear of polycrystalline cubic boron nitride (PcBN) tools was investigated in oblique turning experiments when machining compacted graphite iron at high cutting speeds, with the intention of elucidating the failure mechanisms of the cutting tools and presenting an analysis of the chip formation process. Dry finish turning experiments were conducted in a CNC lathe at cutting speeds in the range of 500–800m/min, at a feed rate of 0.05mm/rev and depth of cut of 0.2mm. Two different tool end-of-life criteria were used: a maximum flank wear scar size of 0.3mm (flank wear failure criterion) or loss of cutting edge due to rapid crater wear to a point where the cutting tool cannot machine with an acceptable surface finish (surface finish criterion). At high cutting speeds, the cutting tools failed prior to reaching the flank wear failure criterion due to rapid crater wear on the rake face of the cutting tools. Chip analysis, using SEM, revealed shear localized chips, with adiabatic shear bands produced in the primary and secondary shear zones.

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