The machinability of powder metallurgy steels is poorer compared with wrought steels of appropriate composition and/or mechanical [properties. The reason for it is a larger number of material and processing variables affecting the final properties of a sintered material. Therefore the machining of powder metallurgy (PM) steels is a permanent subject of investigation and practice. The aim of the book is to make on the basis of present knowledge an overview of all interacting factors in machining process including those applied for the improvement of the machinability. There are the properties of basic plain iron and alloyed powders, various additions, compaction and sintering conditions. Effect of porosity, individual alloying elements and microstructure character is considered. The description of the basic machining processes with their characteristics and with the characteristics of the tool geometry belongs to the mentioned factors. For the improvement of machinability of PM steels different machining aids, as S, MnS, MoS2 and other are frequently used and their chemical and physical characteristics are given.
The effect of various machining aids used on machinability of sintered plain iron, iron-carbon and of steels alloyed with Cu, Ni, Mo, Cr, Mn including powder forged steels with very different mechanical properties and very different microstructures is analysed and summarized. The high-speed steel, hardmetal and other tools with their geometry as the part of the cutting process are described in relation to the sintered powder materials. The recommendations for machining of various steels enclose the present knowledge about the machinability of powder metallurgy steels.
1. INTRODUCTION 2. Powder Metallurgy Processes and MaterialS (metal powder production; chemical, physical and technological characteristics of metal powders; mixing and compaction; sintering; alloying methods and alloying elements; secondary operations; porosity and mechanical properties of sintered iron and steel) 3. Principles of Machining of Steel (machining processes; characterisation of machining processes; analysis of the machining process; machinability testing) 4. Cutting Tools (cutting tool materials; high speed steels; hardmetals; stellite; cermets; ceramics; cubic boron nitride; polycrystalline diamond (PCD); tool coatings and hardening processes; cutting tool wear and tool life; cutting tools, workpiece material and surface integrity) 5. Factors Influencing the Machinability of PM Steels (effect of processing characteristics on machinability; effect of material characteristics on machinability) 6. Measures to Improve the Machinability of PM Steels (machining aids in PM; role of machining aids in machining process; metal sulphide characteristics and effects; manganese sulphide characteristics; sulphides of other elements; production processes; microstructure modification; green machining; effect of machining operations; tool coating) 7. Machining of Sintered Steels - State of the Art (plain iron and iron-carbon steels; iron-copper-carbon steel; nickel alloyed steels; diffusion alloyed steels; stainless steel; effect of density and sintering temperature and atmosphere; comparing the machinabiulity of various steels under different cutting conditions; drilling test with constant thrust force; effect of some machining aids on machinability of various alloys; machinability vs. mechanical and other characteristics of PM; high machinability rating PM steels and conditions; standardizing the machinability of PM steels; special processing and machining routes for high-strength - hardness PM metals; green machining; heat treatment processes and machinability; machining of powder forged steels) 8. Recommendations for Machining of PM Steels (recommendations for drilling; selection of drill type; recommendations for turning; cutting tools and general cutting conditions; specific recommendations and cutting data; tapping and threading; recommendations and cutting data for milling, reaming, broaching and green machining; parameters for optimizing machining of PM parts) APPENDIX REFERENCES INDEX
Number Of Pages: 556
Published: 1st May 2005
Publisher: Cambridge International Science Publishing
Country of Publication: GB
Dimensions (cm): 23.4 x 15.6
Weight (kg): 0.95