Methodology for evaluating effectd of material characteristics on machinability - theory and statistics-based modelling applied on alloy 718
Artikel i vetenskaplig tidskrift, 2011

The potential machinability for Alloy 718 (Inconel 718) is examined in terms of five material characteristics considered to play a key role in the machinability: ductility elongation to fracture), strain hardening (ultimate tensile strength over yield strength), thermal conductivity, yield strength and abrasiveness (amount of carbides). The material characteristics are simulated with the software JMatPro from Sente software. The effects of composition, grain size, hardness (size of the precipitated intermetallic particles for given volume fraction), heat treatment, temperature and strain rate have been modelled and statistically evaluated. Combining thermodynamics-based modelling (JMatPro), design of experiments and statistical analysis Minitab), and machinability polar diagram, a concept on methodology to assess variations in material specifications and to optimise these specifications with respect to potential machinability has been developed. The mechanical properties, predicted from the meta-modelling are found to be affected by the same parameters: hardness (intermetallic particles characteristics), grain size, amount of aluminium, strain rate and temperature. The abrasiveness should only be affected by the amount of carbon. Simulated material characteristics for two different types of turbine discs were compared with measured tool wear from production environment machining experiments. Variations in material characteristics between the discs were small as well as the critical tool wear, revealing a robust metal cutting process.

Material properties .Machinability

Alloy 718

Modelling

Metal cutting

Författare

Stefan Olovsjö

Chalmers, Material- och tillverkningsteknik, Yt- och mikrostrukturteknik

Peter Hammersberg

Chalmers, Material- och tillverkningsteknik, Avancerad oförstörande provning

Pajazit Avdovic

Siemens Industrial Turbomachinery AB

Lunds universitet

J. E. Stahl

Lunds universitet

Lars Nyborg

Chalmers, Material- och tillverkningsteknik, Yt- och mikrostrukturteknik

International Journal of Advanced Manufacturing Technology

0268-3768 (ISSN) 1433-3015 (eISSN)

Vol. 59 55-66

Ämneskategorier

Materialteknik

Bearbetnings-, yt- och fogningsteknik

Styrkeområden

Produktion

Materialvetenskap

DOI

10.1007/s00170-011-3503-3