摘要:

AbstractThe various tests usually applied to powders for the manufacture of porous bronze are listed. Stress is laid on the importance of consistency of materials. Variations in the important properties of each of the metallic and non-metallic ingredients, and their effect on pressing and sintering behaviour, are discussed. The conclusion reached is that a compromise on powder properties must be accepted in order to achieve economic production.

ISSN:0032-5899    

DOI:10.1179/pom.1961.4.7.011

出版商:Taylor&Francis    

年代:1961

数据来源: Taylor

摘要:

AbstractSome twenty different iron powders are available in Europe for the manufacture of sintered bearings and structural parts. These powders can be grouped under four headings: reduced, atomized, comminuted, and electrolytic. Details are given of the experience gained in testing these types of powder by the methods in common use in the metal-powder industry.The influence of the data thus obtained on the processing, in particular the pressing and sintering conditions, of iron powders is discussed in detail. Consideration is given to the way in which the properties of the powders affect their sinterability, the pressing operation and tool design, and also the physical characteristics of the finished product.

ISSN:0032-5899    

DOI:10.1179/pom.1961.4.7.012

出版商:Taylor&Francis    

年代:1961

数据来源: Taylor

摘要:

AbstractAn investigation is described of problems encountered in the conventional powder metallurgy of titanium, with particular reference to the pressing and sintering characteristics of titanium and titanium hydride powders and to sources of contamination. It is concluded that, for success to be achieved in the production of fully dense sintered material by the present method without incurring serious contamination, commercial titanium would have to be available as powder conforming to strict purity requirements.

ISSN:0032-5899    

DOI:10.1179/pom.1961.4.7.013

出版商:Taylor&Francis    

年代:1961

数据来源: Taylor

摘要:

AbstractTwo methods for forming shaped bodies in beryllium by powder metallurgy are described and compared. The requirements for uniform densification during hot pressing are discussed, and it is concluded that a double-pressing method is essential if thin-walled hemispherical shapes are required.

ISSN:0032-5899    

DOI:10.1179/pom.1961.4.7.014

出版商:Taylor&Francis    

年代:1961

数据来源: Taylor

摘要:

AbstractThe preparation of titanium hydride powder and the method of adding aluminium and manganese are described. Sintered materials had poor ductility and this is attributed to the presence of an acicular structure. The tensile strength and ductility of sintered and forged alloys, in which the acicular structure is destroyed, were as good as, and in some cases superior to, those of the equivalent conventional cast and wrought alloy. Both the sintered and the sintered and forged material exhibited good creep properties at 200 and 400°C. Attempts to destroy the acicular structure of the sintered alloy by heat-treatment were unsuccessful.

ISSN:0032-5899    

DOI:10.1179/pom.1961.4.7.015

出版商:Taylor&Francis    

年代:1961

数据来源: Taylor

摘要:

AbstractThe apparent activation energy for the following reactions has been determined by measuring the amount of carbon removed from samples of powder heated to various temperatures in an atmosphere of either dry or wet hydrogen:Dry Hydrogen“As-carburized”tungsten carbide: no reaction up to 900°C.Water–milled tungsten carbide: 8·38 kcal/mole over the range 600–900°C.Water–milled tungsten carbide+ 6% cobalt: complex reaction over the range 600–900°C.Wet Hydrogen“As-carburized”tungsten carbide: 58·1 kcal/mole over the range 800–900°C.Water–milled tungsten carbide: 34·8 kcal/mole over the range 700–900°C.Water–milled tungsten carbide+ 6% cobalt: 38·4 kcal/mole over the range 825–900°C; 7·38 kcal/mole over the range 600–800°C.It has been shown that ball-milling in water changes both the physical and chemical properties of tungsten carbide powder. These changes are discussed in relation to the marked differences in reaction rates. A number of possible reasons for these differences are given.

ISSN:0032-5899    

DOI:10.1179/pom.1961.4.7.016

出版商:Taylor&Francis    

年代:1961

数据来源: Taylor

ISSN:0032-5899    

DOI:10.1179/pom.1961.4.7.017

出版商:Taylor&Francis    

年代:1961

数据来源: Taylor