Search results

For additive manufacturing (AM) through laser-based powder bed fusion of polymers (PBF-LB/P), accurate characterization of powder flowability is vital for achieving high-quality parts. However, accurately characterizing feedstock flowability presents challenges because of a lack of consensus on which tests to perform and the diverse forces and mechanisms involved. This study aims to undertake a thorough investigation into the flowability of eight feedstock materials for PBF-LB/P at different temperatures using various techniques.

For ambient temperature assessments, established metrics such as avalanche angle and Hausner ratio, along with the approximated flow function coefficient (FFC_app), are used. The study then focuses on the influence of elevated temperatures representative of in-process conditions. FFC_app and differential scanning calorimetry (DSC) are performed and analyzed, followed by a correlation analysis as a holistic approach to identify key aspects for flowability. Furthermore, two feedstock materials are compared with a previous study to connect the present findings to PBF-LB/P processing.

The study revealed intrinsic material properties such as mechanical softening near the melting point to become significant. This partially explains why certain powders with poor ambient temperature flowability are consistently demonstrated to produce high-quality parts. FFC_app and thermal characterization through DSC are identified as critical metrics for optimizing feedstock material characteristics across temperature ranges.

Previous studies emphasized specific characterizations of feedstock material at ambient temperature, presented a limited materials selection or focused on metrics such as shape factors. In contrast, this study addresses a partially understood aspect by examining the critical role of temperature in governing feedstock material flowability. It advocates for the inclusion of temperature variables in flowability analyses to closely resemble the PBF-LB/P process, which can be applied to material design, selection and process optimization.

For the past twenty‐five years or so, the writings of George Orwell — especially his final novel 1984 — have been a popular topic for student research. From junior high through graduate school, interest in Orwell has been consistent. Book reports, term papers, and even seminars on Orwell are common‐place in the national curriculum. Now, as the year 1984 arrives, librarians at all levels — public, school, academic — must brace themselves for a year‐long onslaught of requests for biographical and critical material on Orwell.

Analysis of organizational decline has become central to the study of economy and society. Further advances in this area may fail however, because two major literatures on the topic remain disintegrated and because both lack a sophisticated account of how social structure and interdependencies among organizations affect decline. This paper develops a perspective which tries to overcome these problems. The perspective explains decline through an understanding of how social ties and resource dependencies among firms affect market structure and the resulting behavior of firms within it. Evidence is furnished that supports the assumptions of the perspective and provides a basis for specifying propositions about the effect of network structure on organizational survival. I conclude by discussing the perspective’s implications for organizational theory and economic sociology.

Analysis of organizational decline has become central to the study of economy and society. Further advances in this area may fail however, because two major literatures on the topic remain disintegrated and because both lack a sophisticated account of how social structure and interdependencies among organizations affect decline. This paper develops a perspective which tries to overcome these problems. The perspective explains decline through an understanding of how social ties and resource dependencies among firms affect market structure and the resulting behavior of firms within it. Evidence is furnished that supports the assumptions of the perspective and provides a basis for specifying propositions about the effect of network structure on organizational survival. I conclude by discussing the perspective's implications for organizational theory and economic sociology.

Index by subjects, compiled by K.G.B. Bakewell covering the following journals: Facilities Volumes 8‐17; Journal of Property Investment & Finance Volumes 8‐17; Property Management Volumes 8‐17; Structural Survey Volumes 8‐17.

Compiled by K.G.B. Bakewell covering the following journals published by MCB University Press: Facilities Volumes 8‐18; Journal of Property Investment & Finance Volumes 8‐18; Property Management Volumes 8‐18; Structural Survey Volumes 8‐18.

Compiled by K.G.B. Bakewell covering the following journals published by MCB University Press: Facilities Volumes 8‐17; Journal of Property Investment & Finance Volumes 8‐17; Property Management Volumes 8‐17; Structural Survey Volumes 8‐17.

Index by subjects, compiled by K.G.B. Bakewell covering the following journals: Facilities Volumes 8‐18; Journal of Property Investment & Finance Volumes 8‐18; Property Management Volumes 8‐18; Structural Survey Volumes 8‐18.

Compiled by K.G.B. Bakewell covering the following journals published by MCB University Press: Facilities Volumes 8‐18; Journal of Property Investment & Finance Volumes 8‐18; Property Management Volumes 8‐18; Structural Survey Volumes 8‐18.