Search results

Filters

  • Journals
  • Authors
  • Keywords
  • Date
  • Type

Search results

Number of results: 4
items per page: 25 50 75
Sort by:
Download PDF Download RIS Download Bibtex

Abstract

While analyzing shape accuracy of ferroalloy precision castings in terms of ceramic moulds physical anisotropy, low-alloy steel castings

("cover") and cast iron ("plate") were included. The basic parameters in addition to the product linear shape accuracy are flatness

deviations, especially due to the expanded flat surface which is cast plate. For mentioned castings surface micro-geometry analysis was

also carried, favoring surface load capacity tp50 for Rmax = 50%.

Surface load capacity tp50 obtained for the cast cover was compared with machined product, and casting plate surface was compared with

wear part of the conveyor belt. The results were referred to anisotropy of ceramic moulds physical properties, which was evaluated by

studying ceramic moulds samples in computer tomography equipment Metrotom 800.

Go to article

Authors and Affiliations

R. Biernacki
R. Haratym
J. Tomasik
J. Kwapisz
Download PDF Download RIS Download Bibtex

Abstract

Inconel 713C precision castings are used as aircraft engine components exposed to high temperatures and the aggressive exhaust gas

environment. Industrial experience has shown that precision-cast components of such complexity contain casting defects like

microshrinkage, porosity, and cracks. This necessitates the development of repair technologies for castings of this type. This paper

presents the results of metallographic examinations of melted areas and clad welds on the Inconel 713C nickel-based superalloy, made by

TIG, plasma arc, and laser. The cladding process was carried out on model test plates in order to determine the technological and materialrelated

problems connected with the weldability of Inconel 713C. The studies included analyses of the macro- and microstructure of the

clad welds, the base materials, and the heat-affected zones. The results of the structural analyses of the clad welds indicate that Inconel

713C should be classified as a low-weldability material. In the clad welds made by laser, cracks were identified mainly in the heat-affected

zone and at the melted zone interface, crystals were formed on partially-melted grains. Cracks of this type were not identified in the clad

welds made using the plasma-arc method. It has been concluded that due to the possibility of manual cladding and the absence of welding

imperfections, the technology having the greatest potential for application is plasma-arc cladding.

Go to article

Authors and Affiliations

J. Adamiec
K. Łyczkowska
Download PDF Download RIS Download Bibtex

Abstract

The paper presents the properties of plastics under the trade names of PMMA and Midas, and of Formowax, Romocast 305 and Romocast 930 casting waxes. Their effect on the quality of foundry patterns used in the manufacture of ceramic moulds for precision casting is also discussed. From the selected materials for foundry patterns, samples were made for testing using the following methods: (i) 3D printing in the case of plastics, and (ii) conventional method based on tooling in the form of metal moulds (dies) in the case of casting waxes.

The most important physico-mechanical properties of materials for foundry patterns were determined, i.e. linear shrinkage, softening temperature, relative elongation and coefficient of thermal linear expansion. Bending tests were carried out on samples of patterns printed and made in metal moulds, including determination of the surface roughness of patterns.

After the process of melting out patterns from the cavities of ceramic moulds in an autoclave, the degree of their melting out was visually assessed (i.e. the residues from pattern removal were evaluated). The ash content after burning out of foundry patterns was also determined. The conducted tests allowed comparing the important parameters of materials used for foundry patterns and assessing the suitability of selected plastics as a material for foundry patterns used in the manufacture of high-quality precision castings.

Go to article

Authors and Affiliations

A. Dydak
M. Książek
Download PDF Download RIS Download Bibtex

Abstract

Inconel 713C alloy belongs to the group of materials with high application potential in the aerospace industry. This nickel alloy has excellent features such as high strength, good surface stability, high creep and corrosion resistance. The paper presents the results of metallographic examinations of a base material and padding welds made by laser beam on the Inconel 713C alloy. The tests were made on precisely cast test plates imitating low - pressure turbine blades dedicated for the aerospace industry. Observations of the macro- and microstructure of the padding welds, heat-affected zone and base material indicate, that the Inconel 713C alloy should be classified as a hard-to-weld material. In the investigated joint, cracking of the material is disclosed mainly in the heat-affected zone and at the melted zone interface, where pad weld crystals formed on partially melted grains. The results show that phases rich with chromium and molybdenum were formed by high temperature during welding process, which was confirmed by EDS analysis of chemical composition.

Go to article

Authors and Affiliations

K. Łyczkowska
J. Adamiec

This page uses 'cookies'. Learn more