Cutting Mechanism of Resin Impregnated Sintered Iron

2010 ◽  
Vol 638-642 ◽  
pp. 1836-1841 ◽  
Author(s):  
Kunio Okimoto
Keyword(s):  
Plastic Deformation ◽  
Thermal Properties ◽  
Flow Stress ◽  
Cutting Force ◽  
Coefficient Of Friction ◽  
Work Hardening ◽  
Fracture Strain ◽  
Cutting Mechanism ◽  
Sintered Iron ◽  
Resin Impregnation

Impregnating resin into the open pores of a sintered iron compact is well known to improve the machinability of the compact. However, the causes of this phenomenon require further investigation. The purpose of this study is to clarify the main cause of the improvement in machinability on resin impregnation. In this study, sintered iron was machined and the influences of resin impregnation on its thermal properties, coefficient of friction, and flow stress (deformation resistance) were investigated. The results indicate that the great improvement in machinability produced by resin impregnation is mainly due to a reduction in the plastic deformation (fracture strain) for chip generation, lowering the degree of work hardening and consequently reducing the cutting force required.

Predicting Cutting Forces for Oblique Machining Conditions

1982 ◽  
Vol 196 (1) ◽  
pp. 141-148 ◽  
Author(s):  
G C I Lin ◽  
P Mathew ◽  
P L B Oxley ◽  
A R Watson
Keyword(s):  
Thermal Properties ◽  
Flow Stress ◽  
Cutting Force ◽  
Plane Strain ◽  
Cutting Forces ◽  
Material Flow ◽  
Cutting Conditions ◽  
Orthogonal Plane ◽  
Simplifying Assumptions ◽  
Experimental Cutting

Using orthogonal (plane strain) machining theory together with certain simplifying assumptions based on experimental observations it is shown how the three components of cutting force in oblique machining can be predicted from a knowledge of the work material flow stress and thermal properties and the cutting conditions. A comparison of predicted and experimental cutting force results is given.

The Role of Microcracks in Large Plastic Deformation

1981 ◽  
Vol 103 (4) ◽  
pp. 431-436 ◽  
Author(s):  
L. H. S. Luong ◽  
R. H. Brown
Keyword(s):  
Plastic Deformation ◽  
Flow Stress ◽  
Work Hardening ◽  
Large Strain ◽  
Strain Rates ◽  
Compression Tests ◽  
Large Plastic Deformation ◽  
Negative Work ◽  
Compressive Stresses

This paper describes the results obtained from shear-compression tests carried out at low strain rates and at strain rates equivalent to those in a typical machining operation. These tests together with metallographic work are used to explain the influence of microcracks on the flow stress of work material. It is shown that the negative work-hardening effect observed at large strain deformation in the presence of compressive stresses is associated with the behavior of microcracks. A mechanism is proposed to account for this phenomenon.

On effect of surface hardening on impact and abrasive wear resistance of Hadfi eld steel

2020 ◽  
pp. 252-255
Author(s):  
V.I. Bolobov ◽  
V.S. Bochkov ◽  
E.V. Akhmerov ◽  
V.A. Plashchinsky ◽  
E.A. Krivokrisenko E.A.
Keyword(s):  
Plastic Deformation ◽  
Wear Resistance ◽  
Abrasive Wear ◽  
Work Hardening ◽  
Surface Hardening ◽  
Cold Work ◽  
Abrasive Wear Resistance ◽  
Hadfield Steel ◽  
Mining Equipment ◽  
Effect Of Surface

On the example of Hadfield steel, as the most common material of fast-wearing parts of mining equipment, the effect of surface hardening by plastic deformation on their impact and abrasive wear resistance is considered. Wear test is conducted on magnetic ironstone as typical representative of abrasive and hard rock. As result of wear of initial samples with hardness of ∼200 HB and samples pre-hardened with different intensities to the hardness of 300, 337 and 368 HB, it is found that during the initial testing period, the initial samples pass the “self-cold-work hardening” stage with increase in hardness to ∼250 HB, which remains virtually unchanged during further tests; the hardness of the pre-hardened samples does not change significantly throughout the tests. It is established that the rate of impact-abrasive wear of pre-hardened samples is significantly (up to 1.4 times) lower than the original ones that are not subjected to plastic deformation, and decreases with increasing degree of cold-work hardening. Preliminary surface hardening by plastic deformation can serve as effective way to increase the service life of fast-wearing working parts of mining equipment.

Deformation Behaviour and Ultrafine Grained Structure Development in Steels with Different Carbon Content Subjected to Severe Plastic Deformation

2007 ◽  
Vol 345-346 ◽  
pp. 45-48 ◽  
Author(s):  
Jozef Zrník ◽  
Sergey V. Dobatkin ◽  
Ondrej Stejskal
Keyword(s):  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
Work Hardening ◽  
Favourable Effect ◽  
Tensile Behaviour ◽  
Dislocation Network ◽  
Strength Increase ◽  
Subgrain Structure ◽  
Low Carbon ◽  
Channel Angle

The article focuses on the results from recent experimental of severe plastic deformation of low carbon (LC) steel and medium carbon (MC) steel performed at increased temperatures. The grain refinement of ferrite respectively ferrite-pearlite structure is described. While LC steel was deformed by ECAP die (ε = 3) with a channel angle φ = 90° the ECAP severe deformation of MC steel was conducted with die channel angle of 120° (ε = 2.6 - 4). The high straining in LC steel resulted in extensively elongated ferrite grains with dense dislocation network and randomly recovered and polygonized structure was observed. The small period of work hardening appeared at tensile deformation. On the other side, the warm ECAP deformation of MC steel in dependence of increased effective strain resulted in more progressive recovery process. In interior of the elongated ferrite grains the subgrain structure prevails with dislocation network. As straining increases the dynamic polygonization and recrystallization became active to form mixture of polygonized subgrain and submicrocrystalline structure. The straining and moderate ECAP temperature caused the cementite lamellae fragmentation and spheroidzation as number of passes increased. The tensile behaviour of the both steels was characterized by strength increase however the absence of strain hardening was found at low carbon steel. The favourable effect of ferrite-pearlite structure modification due straining was reason for extended work hardening period observed at MC steel.

Effect of Hydrogen on the Development of Superplastic Deformation in the Submicrocrystalline Ti–6Al–4V Alloy

2016 ◽  
Vol 838-839 ◽  
pp. 344-349 ◽  
Author(s):  
Galina P. Grabovetskaya ◽  
Ekaterina N. Stepanova ◽  
Ilya V. Ratochka ◽  
I.P. Mishin ◽  
Olga V. Zabudchenko
Keyword(s):  
Solid Solution ◽  
Plastic Deformation ◽  
Flow Stress ◽  
Superplastic Deformation ◽  
Deformation Localization ◽  
Solid Solution Strengthening ◽  
Solution Strengthening ◽  
Hydrogenation Effect

Hydrogenation effect on the development of superplastic deformation in the submicrocrystalline Ti–6Al–4V alloy at temperatures (0.4–0.5)Тmelt is investigated. Hydrogenation of the submicrocrystalline Ti–6Al–4V alloy to 0.26 mass% during superplastic deformation is found to result in solid solution strengthening, plastic deformation localization, and as a consequence, decrease of the deformation to failure. Possible reasons for the decrease of the flow stress and increase of the deformation to failure in the submicrocrystalline Ti–6Al–4V–0.26H alloy during deformation under conditions of superplasticity and simultaneous hydrogen degassing from the alloy are discussed.

scholarly journals Cutting Force Prediction Models by FEA and RSM When Machining X56 Steel with Single Diamond Grit

Micromachines ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 326
Author(s):  
Lan Zhang ◽  
Xianbin Sha ◽  
Ming Liu ◽  
Liquan Wang ◽  
Yongyin Pang
Keyword(s):  
Cutting Force ◽  
Coefficient Of Friction ◽  
High Speed ◽  
Prediction Models ◽  
Pipeline Steel ◽  
Cutting Speed ◽  
Depth Of Cut ◽  
Cutting Force Prediction ◽  
Force Prediction ◽  
Diamond Wire Saw

In the field of underwater emergency maintenance, submarine pipeline cutting is generally performed by a diamond wire saw. The process, in essence, involves diamond grits distributed on the surface of the beads cutting X56 pipeline steel bit by bit at high speed. To find the effect of the different parameters (cutting speed, coefficient of friction and depth of cut) on cutting force, the finite element (FEA) method and response surface method (RSM) were adopted to obtain cutting force prediction models. The former was based on 64 simulations; the latter was designed according to DoE (Design of Experiments). Confirmation experiments were executed to validate the regression models. The results indicate that most of the prediction errors were within 10%, which were acceptable in engineering. Based on variance analyses of the RSM models, it could be concluded that the depth of the cut played the most important role in determining the cutting force and coefficient the of friction was less influential. Despite making little direct contribution to the cutting force, the cutting speed is not supposed to be high for reducing the coefficient of friction. The cutting force models are instructive in manufacturing the diamond beads by determining the protrusion height of the diamond grits and the future planning of the cutting parameters.

Microstructural Change of Beta Type Titanium Alloy by Intense Plastic Deformation

2006 ◽  
Vol 503-504 ◽  
pp. 705-710 ◽  
Author(s):  
Goroh Itoh ◽  
Hisashi Hasegawa ◽  
Tsing Zhou ◽  
Yoshinobu Motohashi ◽  
Mitsuo Niinomi
Keyword(s):  
Plastic Deformation ◽  
Work Hardening ◽  
Static Recrystallization ◽  
True Strain ◽  
Microstructural Change ◽  
Intense Plastic Deformation ◽  
Rolled Plate ◽  
Al Alloy ◽  
Hot Rolled ◽  
Zr Alloy

Usual static recrystallization treatment and a method to provide intense plastic deformation, ARB namely Accumulative Roll-Bonding, have been applied to two beta type titanium alloys, i.e. Ti-29Nb-13Ta-4.6Zr and Ti-15V-3Cr-3Sn-3Al. Microstructural change as well as work-hardening behavior was examined as a function of plastic strain. Both the work-hardening rate and the hardness at the initial as-hot-rolled state were smaller in the Ti-Nb-Ta-Zr alloy than in the Ti-V-Cr-Sn-Al alloy. Recrystallized grains of 14μm in size were obtained by the usual static recrystallization treatment, which was significantly smaller than that of the starting as-hot-rolled plate of 38μm. No significant change other than flattening and elongating of the original grains was found in the optical microscopic scale. It was revealed, however, from a TEM observation combined with selected area diffraction technique that geometric dynamic recrystallization occurred in the Ti-Nb-Ta-Zr alloy deformed at room temperature by a true strain of 5, resulting in an ultra-fine-grained microstructure where the grain size was roughly estimated to be about 100nm.

Enhancement of tribological properties and characteristic of polymer matrix composite (UHMWPE reinforced with short fibres of polyester) for Total Disc Replacement (TDR)

2020 ◽  
Vol 2 (102) ◽  
pp. 55-65
Author(s):  
M.N. Obaid ◽  
S.H. Radhi
Keyword(s):  
Surface Roughness ◽  
Contact Angle ◽  
Wear Resistance ◽  
Composite Material ◽  
Thermal Properties ◽  
Coefficient Of Friction ◽  
Tribological Properties ◽  
Total Disc Replacement ◽  
Short Fibres ◽  
The Matrix

Purpose: The number of people suffering from Degenerative Disc Disease (DDD) is increasing. The disease causes heavy pain and restrict a number of day-to-day life activities. In extreme cases, the degraded disc is removed under total disc replacement which is usually made up of Ultra-High Molecular Weight Polyethylene (UHMWPE). The material has astounding biocompatible characteristics mechanical properties and wear resistance. However, these characteristics are insufficient in arthroplasty application. Therefore, research investigations are ongoing to improve tribological properties through reinforcement that may result in a composite material of UHMWPE. Thus the current study is aimed at reinforcing UHMWPE with short fibres of polyesters to enhance the tribological properties and surface characteristic so as to improve wear resistance and nourish the fibroblast cells on synthetic disc. Design/methodology/approach: The researcher prepared UHMWPE composite material, reinforced with different weight fractions of short polyester fibres (2, 4, 6, 8 and 10% following hot press method. Further pin-on-disc device was used to study the tribological properties (coefficient of friction and volume of wear). The study tested surface roughness and surface characteristics by atomic force microscopy (AFM) device, hardness by shore D device, contact angle to study the effect of polyester short fibres on wettability of UHMWPE surface and tested the thermal properties and crystalline degree using Differential Scanning Calorimetry measurement (DSC) device. Findings: The results infer that the wear resistance got improved when using 2% w.t polyester though it got decreased initially. However, the value was still more than neat UHMWPE. There was a decrease observed in coefficient of friction, but after 4 w.t% polyester, the coefficient of friction got increased due to increasing percentage of fibres which make it harder and stiff compared to UHMWPE. There was a decline observed in surface roughness due to alignment of the fibres with smooth surface. The contact angle got increased in a moderate range while the roughness enhanced the growth of fibroblast cell. The hardness of composite material got increased, because the fibres turned stiffer and harder than the matrix. DSC results infer the improvements in thermal stability due to high thermal properties of polyester fibres compared to UHMWPE. The degree of crystallinity got increased which in turn enhanced wear resistance, especially at 6 w.t % polyester fibres. There was a mild increase observed in density since the density of polyester is higher than polymer. Research limitations/implications: The major challenge was the dispersion of fibres. Uniform distribution of fibres within the matrix (UHMWPE) was achieved through two steps of mixing processes such as mechanical mixture and twin extruder. In future studies, fatigue tests must be conducted to study the behaviour of prepared composite materials under fatigue cycle. Practical implications: A significant objective is how to connect among different properties to obtain good improvement in tribological and surface properties so as to enhance wear resistance and growth of fibrolase cells. Originality/value: In this study, polymeric short fibres were used as reinforcement with polymeric matrix to enhance the wettability of fibres with matrix. In this way, the bonding among them got increased which supports the tribological, surface, and crystalline behaviour.

Microtexture Development and Flow Stress Saturation during Triaxial Forging of an Al-3Mg-Sc(Zr) Alloy

2007 ◽  
Vol 546-549 ◽  
pp. 793-800
Author(s):  
S. Ringeval ◽  
David Piot ◽  
Julian H. Driver
Keyword(s):  
Flow Stress ◽  
Work Hardening ◽  
Room Temperature ◽  
Specific Work ◽  
Textural Evolution ◽  
Spatially Resolved ◽  
Grain Fragmentation ◽  
New Type ◽  
Grain Coalescence ◽  
Zr Alloy

An Al-3%Mg-0.25%Sc-0.12%Zr alloy was deformed by triaxial forging at 20-400°C up to strains of about 3. A study of its textural evolution reveals the tendency towards three symmetrical variants of a <110><1 10 ><001> component. This experimental observation is supported by a 3D spatially resolved crystal plasticity analysis. Samples strained at room temperature undergo grain fragmentation in the form of fine substructures and relatively weak textures. Conversely, at 300°C and above, more homogeneous intergranular deformation and rotations give rise to stronger textures. This eventually encourages grain coalescence and thus the development of interpenetrating “orientation chains”, creating a new type of microstructure. The influence of this texture development on the specific work hardening behaviour is discussed.

Sign in / Sign up

Export Citation Format

Share Document