Showing papers in "International Materials Reviews in 1968"
TL;DR: Maraging steels are a class of high-strength steels characterised by very low carbon contents and the use of substitutional elements to produce age-hardening in iron-nickel martensites as mentioned in this paper.
Abstract: Maraging steels are a class of high-strength steels characterised by very low carbon contents and the use of substitutional elements to produce age-hardening in iron–nickel martensites. The term 'maraging' was coined from a combination of martensite and age-hardening.
103 citations
TL;DR: Although ductile fracture is a continuing problem to the fabricator, fundamental work on this phenomenon is somewhat limited as mentioned in this paper. Part of the reason for this is the great theoretical complexity of the problem and the difficulty in doing clear-cut experiments.
Abstract: Although ductile fracture is a continuing problem to the fabricator, fundamental work on this phenomenon is somewhat limited. Part of the reason for this is the great theoretical complexity of the problem and the difficulty in doing clear-cut experiments. However, significant progress has been made in recent years toward elucidating the mechanisms and controlling variables. This progress is outlined in the following sections.
42 citations
TL;DR: A refractory metal, it is commonly agreed, is a metal with a high melting point as discussed by the authors, however, there is no agreement on the lower limit of melting temperature which defines the group.
Abstract: A refractory metal, it is commonly agreed, is a metal with a high melting point. There is no agreement, however, on the lower limit of melting temperature which defines the group. This is usually s...
38 citations
TL;DR: Fracturing behaviours are complex and involve complex interactions among the agents of separation: mechanical forces and distortions, activity of the environment upon the surface of the metal, and the inherent metallurgical structure leading to the nucleation and growth of fractures as mentioned in this paper.
Abstract: Fracturing behaviours are complex and involve complex interactions among the agents of separation: mechanical forces and distortions, activity of the environment upon the surface of the metal, and the inherent metallurgical structure leading to the nucleation and growth of fractures. When we succeed in isolating any one of these three, or characterising interactions between any two, our understanding of the processes leading to structural failure is enhanced. Indeed, to isolate one effect, the other two must be known or held constant. It is for this reason that the mechanics of fracturing, as one agent, is so essential to studies of corrosive environmental influences, as another agent. Fracture mechanics provides a way to normalise out the effects of the mechanical conditions peculiar to variations in cracksize and shape and the stress which this material discontinuity refuses to support. To the extent that linear elasticity describes the mechanical 'environment', the principle of superposition p...
32 citations
TL;DR: The diffusion coefficient is defined as the proportionality constant between the mass flux of a component in a system and the concentration gradient that gives rise to this flux as mentioned in this paper, and is defined by the authors of this paper.
Abstract: Definition and significance of diffusion coefficientsThe Diffusion Coefficient is usually defined as the proportionality constant between the mass flux of a component in a system and the concentration gradient that gives rise to this flux.
22 citations
TL;DR: The term "cutting tool" can be applied to almost any instrument employed to divide, sever, or penetrate any solid body, provided the instrument has an edge as discussed by the authors, which includes the razor blade, the tailor's scissors, and the bread knife, as well as the twist drill, the milling cutter and the saw.
Abstract: The term 'cutting tool' can be applied to almost any instrument employed to divide, sever, or penetrate any solid body, provided the instrument has an edge. This category includes the razor blade, the tailor's scissors, and the bread knife, as well as the twist drill, the milling cutter, and the saw. The present review will be confined to the materials for tools in the engineering industry. Even in this restricted field a great number of tools of very different sizes and shapes is employed to carry out many different operations on almost all the materials of construction used by the engineer. Engineering tools include single-edge lathe tools for turning, boring, facing, planing, and parting off; twist drills and reamers for shaping holes; milling cutters and routing cutters for producing plane surfaces and slots; hobbing cutters for generating gear teeth; broaching tools; form tools; saws; and many others.
22 citations
TL;DR: The surface tension of liquid mercury at 25°C was shown to be 485 dynes/cm in this article, within a narrow margin of error, and it was shown that the surface tension can be maintained within a 1.5 degree error.
Abstract: As shown in Table 1, within a narrow margin of error the surface tension of liquid mercury at 25° C is 485 dynes/cm.
11 citations
TL;DR: The first commercial production of manganes by an electrolytic method during the 1940s was described in this article, where the first successful experiments of Allmand and Campbell in 1923 were carried out in a laboratory scale.
Abstract: Large quantities of manganes in a state of fairly high purity (99.5–99.9%) have been generally available only since the first commercial production of the metal by an electrolytic method during the 1940s. Previously, it had been processed electrolytically by individuals on merely a laboratory scale, subsequent to the first successful experiments of Allmand and Campbell in 1923. For this reason, very few of the experiments carried out on the physical and other properties of manganese before the late 1940s were made on metal that for research purposes may now be termed high-purity.
5 citations
TL;DR: A review of the important papers dealing with powder-metallurgy (P.M.) parts can be found in this paper, where the focus is mainly limited to the metals commonly used in the manufacture of P.M. parts.
Abstract: This review covers most of the important papersthat have appeared since about 1960 dealing with some facet of the production of powder-metallurgy (P.M.) parts. The scope has been mainly limited to the metals commonly used in the manufacture of P.M. parts—iron, copper, tin, and nickel—and the production of friction materials and filters has not been included.
2 citations
TL;DR: The major advances in the heat-treatment of alloy steels during the last thirty years have been in our understanding of the processes involved as mentioned in this paper, which has enabled substantial improvements to be made in mechanical properties, especially in strength and toughness.
Abstract: The major advances in the heat-treatment of alloy steels during the last thirty years have been in our understanding of the processes involved. We now know much more about the role of carbon, the importance of alloying elements, the types of microstructure resulting from heat-treatment, and the ways in which these microstructures may be influenced by departures from simple heat-treatment processes, as in austempering, and by the interpolation of other processes, such as mechanical working, during heat-treatment. A greater insight has also been gained into the relationships between microstructure and mechanical properties, due largely to the increasing use of transmission electron microscopy, and this has enabled substantial improvements to be made in mechanical properties, especially in strength and toughness.
1 citations
TL;DR: In this paper, a review of small-scale tests based on turning or drilling has been conducted to investigate the influence of variations in test conditions on machinability results of cutting tools.
Abstract: Production-scale machining trials are too costly in material and time to be useful for quality control in manufacture or for a preliminary assessment of experimental properties. Unfortunately, the validity of rapid, small-scale tests is not widely accepted The purpose of this review is to establish which small-scale tests, based on turning or drilling, have been successfully employed in developing new materials, and to illustrate by typical results the use of such tests to detect variations in structure or composition. These results also serve to show that certain tests, properly interpreted, have given consistent trends with different investigators. It is not intended to describe testing procedures in detail, nor to consider tests specifically for cutting-tool materials. The mechanics of cutting is discussed only in so far as it explains the influence of variations in test conditions on machinability results. Finally, although the relationship between machinability and structure or composition is...