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Transverse properties of fibrous composites
SYSTEMATIC
ABSTRACTS
OF CURRENT
LITERATURE
A Review of Theories of Metal Removal in Grinding. .4. G. Wetton,J. Mech. Eng. Sci., II (4) (1969) 412-425; 10 figs., I table, 80 refs. The paper reviews theories of metal removal in grinding which have resulted in a considerable step forward in understanding the fundamental parameters, though no complete solution is yet available. Much is known about the shape of abrasive grit, the nature of their cutting edges and how these are affected by the various wear mechanisms prevailing during grinding to produce sharp edges by fracture, or dulled abrasive by chemical or attritious wear. Experiments have demonstrated the importance of considering both forward and lateral flow of metal and have shown the difference from conventional metal cutting. Chip formation in the conventional manner occurs and metal is also removed as slivers, resembling chips from the side walls of grooves resulting from lateral metal flow. The influences of speed, friction, lubrication and grit distribution need to be more closely examined before experimental results of grinding simulation can be accurately assessed.
Transverse Properties of Fibrous Composites. P. E. Chen and J. M. Lin, Matev. Res. Stds., 9
(8) (1969) 29-33; 14 figs. The transverse stiffness and strength of unidirectional fibre reinforced composites have been calculated by using the fine-element method and von Mises-Hencky criterion. The conditions of perfect bonding and total debonding have been included in the strength calculations. Experimental work has been carried out on boron-aluminium and stainless steel-aluminium composites; properties being increased as functions of fibre volume content. Theoretical results are compared with experimental data the metalmatrix composites and also for glass-epoxy composites. The Machining of Metals. E. J. A. Armaregoand R. H. Brown, Prentice Hall, Inc., Englewood Cliffs, N.J., 1969; 437 pp., 23 cm; 140 s. The authors analyse the mechanics of metal cutting and consider the phenomena of plastic flow, fracture, wear and vibration. The abrasive process, ultrasonic and electrical discharge processes are discussed. In addition tool life and the economics of machining are covered. 5.2.
Wear phenomena
A Study of Oxidation Corrosive Wear. F. F. Tao, ASLE Trans.,~ 8 figs.,
26 refs.
Phenomena (2)
in
(1969) 97-105;
30.5
A mathematical model based on the existing theories of corrosion and wear is proposed for analysing the controlling phenomena in corrosive wear caused by atmospheric oxygen and is applied to experimental data assuming all wear proceeded by a corrosive mechanism i.e. growth of an oxide layer and its removal by rubbing action. The results show that the rate of metal oxidation is the more important factor in the determination of wear rate. The increase of wear at higher loads can be explained by a simple increase in oxidation rate at higher surface temperature.
A Mathematical Model of Spalling Fatigue Failure in Rolling Contact. Y. P. Chiu, T. E. Tallian, J. L. McCool and J. A. Martin, ASLE Trans., 12 (2) (1969) 106-116; 2 figs., 26 refs. Variables affecting the fatigue life of a rolling contact bearing are identified. A mathematical model for thepredictionof the life of rolling contacts is proposed based on a concept of crack propagation from pre-existing defects. Numerous parameters characterising the material and geometry of the contact and the operating conditions are incorporated, including load, lubrication, matrix strength, defect population and defect severity. The new model comprises current standard bearing life prediction formulae as a special case.
Against Wear. 1. The Basic Mechanisms of Wear. K. H. R. Wright, Tribology, 2 (3) (1969)
Designing
152-161; 13 figs., 2 tables, 28 refs. The introductory article of a series aimed at aiding the engineer in wear diagnosis and improved design. The different types of wear are outlined and their basic mechanisms discussed.
G. INSTRUMENTATION
4ND
TESTING
6.1. Instrumentation
The ISRID Hot Hardness Testing Machine. P. Rabbe and G. Pomey, Mater. Res. Stds., g (8) (1969) 26-28; 4 figs. The instrument enables Vickers hardness tests to be carried out at temperatures between 2o°C and I 100°C in vacua or in a flow of inert gas using loads from I to 20 kg applied for times which can be varied from several seconds to several hours. Load is applied by means of a moving core electromagnet; a compact arrangement which reduces the number of gas tight joints. Successful applications include the study of ageing of steels and the determination of the hot hardness of high-speed tool steels, iron oxides, etc.
Wear, 14 (1969) 296-307
ABSTRACTS
OF CURRENT
LITERATURE
A Review of Theories of Metal Removal in Grinding. .4. G. Wetton,J. Mech. Eng. Sci., II (4) (1969) 412-425; 10 figs., I table, 80 refs. The paper reviews theories of metal removal in grinding which have resulted in a considerable step forward in understanding the fundamental parameters, though no complete solution is yet available. Much is known about the shape of abrasive grit, the nature of their cutting edges and how these are affected by the various wear mechanisms prevailing during grinding to produce sharp edges by fracture, or dulled abrasive by chemical or attritious wear. Experiments have demonstrated the importance of considering both forward and lateral flow of metal and have shown the difference from conventional metal cutting. Chip formation in the conventional manner occurs and metal is also removed as slivers, resembling chips from the side walls of grooves resulting from lateral metal flow. The influences of speed, friction, lubrication and grit distribution need to be more closely examined before experimental results of grinding simulation can be accurately assessed.
Transverse Properties of Fibrous Composites. P. E. Chen and J. M. Lin, Matev. Res. Stds., 9
(8) (1969) 29-33; 14 figs. The transverse stiffness and strength of unidirectional fibre reinforced composites have been calculated by using the fine-element method and von Mises-Hencky criterion. The conditions of perfect bonding and total debonding have been included in the strength calculations. Experimental work has been carried out on boron-aluminium and stainless steel-aluminium composites; properties being increased as functions of fibre volume content. Theoretical results are compared with experimental data the metalmatrix composites and also for glass-epoxy composites. The Machining of Metals. E. J. A. Armaregoand R. H. Brown, Prentice Hall, Inc., Englewood Cliffs, N.J., 1969; 437 pp., 23 cm; 140 s. The authors analyse the mechanics of metal cutting and consider the phenomena of plastic flow, fracture, wear and vibration. The abrasive process, ultrasonic and electrical discharge processes are discussed. In addition tool life and the economics of machining are covered. 5.2.
Wear phenomena
A Study of Oxidation Corrosive Wear. F. F. Tao, ASLE Trans.,~ 8 figs.,
26 refs.
Phenomena (2)
in
(1969) 97-105;
30.5
A mathematical model based on the existing theories of corrosion and wear is proposed for analysing the controlling phenomena in corrosive wear caused by atmospheric oxygen and is applied to experimental data assuming all wear proceeded by a corrosive mechanism i.e. growth of an oxide layer and its removal by rubbing action. The results show that the rate of metal oxidation is the more important factor in the determination of wear rate. The increase of wear at higher loads can be explained by a simple increase in oxidation rate at higher surface temperature.
A Mathematical Model of Spalling Fatigue Failure in Rolling Contact. Y. P. Chiu, T. E. Tallian, J. L. McCool and J. A. Martin, ASLE Trans., 12 (2) (1969) 106-116; 2 figs., 26 refs. Variables affecting the fatigue life of a rolling contact bearing are identified. A mathematical model for thepredictionof the life of rolling contacts is proposed based on a concept of crack propagation from pre-existing defects. Numerous parameters characterising the material and geometry of the contact and the operating conditions are incorporated, including load, lubrication, matrix strength, defect population and defect severity. The new model comprises current standard bearing life prediction formulae as a special case.
Against Wear. 1. The Basic Mechanisms of Wear. K. H. R. Wright, Tribology, 2 (3) (1969)
Designing
152-161; 13 figs., 2 tables, 28 refs. The introductory article of a series aimed at aiding the engineer in wear diagnosis and improved design. The different types of wear are outlined and their basic mechanisms discussed.
G. INSTRUMENTATION
4ND
TESTING
6.1. Instrumentation
The ISRID Hot Hardness Testing Machine. P. Rabbe and G. Pomey, Mater. Res. Stds., g (8) (1969) 26-28; 4 figs. The instrument enables Vickers hardness tests to be carried out at temperatures between 2o°C and I 100°C in vacua or in a flow of inert gas using loads from I to 20 kg applied for times which can be varied from several seconds to several hours. Load is applied by means of a moving core electromagnet; a compact arrangement which reduces the number of gas tight joints. Successful applications include the study of ageing of steels and the determination of the hot hardness of high-speed tool steels, iron oxides, etc.
Wear, 14 (1969) 296-307