The results from experimental research of deformation by upsetting and die forging of lead specimens wit controlled impact are presented. Laboratory setup for conducting the investigations, which uses cold rocket engine operated with compressed air, is described. The results show that when using controlled impact is achieving greater plastic deformation and consumes less impact energy than at o...

Abstract The 17–4 Precipitation Hardening Stainless Steel (PH SS) manufactured by Selective Laser Melting (SLM) has wide application perspectives, but they are limited due to defects and anisotropy. selection of the appropriate process variables plays a fundamental part in microstructure determination final mechanical corrosion properties. main purpose this study is analyze behavior, hardness P...

In cold-work applications, tool steels with high carbide contents are used as cutting and stamping tools. The service life is limited by wear resistance fatigue strength. relationship between manufacturing-related microstructural influences strengths of has not yet been adequately investigated. To investigate these on high-cycle (HCF) strength (NG = 107), rotating bending tests performed AISI D...

Aluminum alloys with nanocrystalline (NC) and ultrafine grain (UFG) size are of interest because of their strengths that are typically 30 pct greater than conventionally processed alloys of the same composition. In this study, UFG AA 5083 plate was prepared by quasi-isostatic (QI) forging of cryomilled powder, and the microstructure and mechanical behavior was investigated and compared with the...

In multi-operation forging processes, the process fault due to missing parts from dies is a critical concern. The objective of this paper is to develop an effective method for detecting missing parts by using automatic classification of tonnage signals during continuous production. In this paper, a new feature selection and hierarchical classification method is developed to improve the classifi...

The paper reports on an investigation into the various aspects of closed die cold forging of polygonal powder preforms, which have been compacted and sintered from atomized powder. It is found that for certain dimensional ratios of the preform the die pressure is minimum. An attempt has been made for the determination of the die pressures developed for given geometries of the disc during the cl...

Within the net-shape and near-net shape technology hot flashless precision forging leads to high forging accuracy of the workpiece with regard to dimensional and surface finish tolerances. The main advantages are shortened production cycles by eliminating machining operations and the saving on raw material lost during machining. By producing ready-to-mount forgings high economical and ecologica...

This paper describes the development of a diagnostic expert system that identifies the cause of various manufacturing defects in hot forging and suggests remedies. The patterns of defect generation are various and due to many possible causes. They depend on part designs, tool designs and process conditions. Pertinent factors include part shape, the state of lubrication, location of the performe...

This paper presents experimental data on the microstructure and martensite transformation temperatures of Ti49.8Ni50.2 (at%) after abc pressing (multi-axial forging) to different true strains e from 1.84 9.55 at 573 K. The show that increasing strain results in grain–subgrain refinement scales a time. With = K, average size measured approximately 130 nm. Decreasing temperature 723 K caused decr...