A cold-work tool steel powder is used to fabricate 3-dimensional objects by selective laser melting using a high-pressure gas atomization process. The spherical powder particles form continuous carbide networks among the austenite matrix and its decomposition products. The carbides comprise Nb-rich MC and Mo-rich M2C. In the SLM process, the process parameters such as the laser power (90 W), layer thickness (25 μm), and hatch spacing (80 μm) are kept fixed, while the scan speed is changed from 50 mm/s to 4000 mm/s. At a low scan speed of 50 mm/s, spherical cavities develop due to over melting, while they are substantially reduced on increasing the speed to 2000 mm/s. The carbide network spacing decreases with increasing speed. At an excessively high speed of 4000 mm/s, long and irregularly shaped cavities are developed due to incomplete melting. The influence of the scan pattern is examined, for which 1 × 1 mm2 blocks constituting a processing layer are irradiated in a random sequence. This island-type pattern exhibits the same effect as that of a low scan speed. Post processing of an object using hot isostatic pressing leads to a great reduction in the porosity but causes coarsening of the microstructure.

The correct computer simulation of the powder compaction stage requires the determination of the elastoplastic parameters which characterize its mechanical behavour. Instrumented dies are frequently used to monitor the longitudinal and radial stress occurring during powder compaction. When strain gages are employed a previous calibration is needed. Many sources of error exist that can lead to the incorrect calibration of the instrumented die. By means of a FEM simulation some of these problems are analysed. The effect of die wall thickness, compression length, and strain location are studied.

The deformation under radial pressure of rectangular dies for metal powder compaction has been investigated by FEM. The explored variables have been: aspect ratio of die profile, ratio between diagonal of the profile and die height, insert and ring thickness, radius at die corners, interference, different insert materials, i. e. conventional HSS, HSS from powders, cemented carbide (10% Co). The analyses have ascertained the unwanted appearance of tensile normal stress on brittle materials, also "at rest", and even some dramatic changes of stress patterns as the die height increases with respect to the rectangular profile dimensions. Different materials behave differently, mainly due to difference of thermal expansion coefficients. Profile changes occur when the dies are heated up to the temperature required for warm compaction. The deformation patterns depend on compaction temperature and thermal expansion coefficients.

본 논문은 엘리엇의 종교관을 기존의 ‘기독교적’이라는 광범위한 개 념대신에 ‘앵글로 가톨릭주의’로 규명하고 이러한 종교관이 드러난 한 예시로서 대성당의 살인에서 사용된 그레고리안 성가, ‘디에스 이레’ 를 제시한다. 그의 종교관을 규명하기 위해, 본 연구는 당대의 영국 국 교회내의 저교회파와 고교회파와의 양상을 확인하고, 성육화 교리를 중 심으로 그 특징을 파악하였다. 복음주의적 저교회파보다는 전통적 교회 로의 회귀를 주장하던 옥스퍼드 운동에 의해 부흥하였던 고교회파의 앵 글로 가톨릭주의는 엘리엇의 성향과 잘 부합된다. 앵글로 가톨릭주의와 그레고리안 성가의 부흥에는 동일하게 옥스퍼드 운동이 동일하게 유발 하였으며, 기존의 복음주의적 성향의 예배식과 평성가 보다는 더욱이 앵글로 가톨릭주의의 엄격한 수행과 관련이 있었다. 또한 ‘디에스 이레’ 의 심판의 날에 대한 주제는 기존의 복음주의보다는 보다 엄격한 앵글 로 가톨릭주의와 관련이 있었다. 기존의 작품에 대한 텍스트의 접근법 뿐 아니라 작품 속 작은 부분을 차지하는 한 성가역시 작품 속 흐르는 엘리엇의 순교에 의미를 함축적으로 드러내고 있음을 확인할 수 있었 다.