Radial mechanical properties of high-temperature dried Norway spruce (Picea abies) wood

2011 ◽  
Vol 6 (3) ◽  
pp. 147-154 ◽  
Author(s):  
Marc Borrega ◽  
Petri P. Kärenlampi
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Picea Abies ◽  
Norway Spruce

Grade yields and wood properties of Norway spruce [Picea abies (L.) Karst.] from the Maritimes

1995 ◽  
Vol 71 (4) ◽  
pp. 473-478
Author(s):  
Y. H. Chui
Keyword(s):  
Mechanical Properties ◽  
Picea Abies ◽  
Norway Spruce ◽  
Wood Quality ◽  
Wood Properties ◽  
Bending Properties ◽  
Clear Wood ◽  
Comparative Information ◽  
Grade Yield

Norway spruce [Picea abies (L.) Karst.] is one of the major non-native softwood species in the Maritimes. A project was undertaken to evaluate the grade yields and mechanical properties of Norway spruce. The project also provided comparative information on the wood quality of two Norway spruce provenances from Germany and Poland. Four plantations were selected for the study with two of these plantations containing trees of known provenances. One plantation was mature and the other three were juvenile. In total, 530 pieces of lumber and the same number of matched small clear specimens were tested for bending properties. Prior to testing, the lumber was visually graded according to both British and Canadian specifications. Quality of lumber varied significantly between sites. Lumber from the Polish provenance had slightly better mechanical properties than that from trees of the German provenance. Compared with published information, the plantation-grown Norway spruce had lower clear wood bending properties and specific gravity than primary eastern Canadian spruce species and balsam fir, and natural Norway spruce grown in Europe. Key words: Norway spruce [Picea abies (L.) Karst.], wood quality, bending properties, grade yield

Effect of abnormal fibres on the mechanical properties of paper made from Norway spruce, Picea abies (L.) Karst.

Holzforschung ◽  
2008 ◽  
Vol 62 (2) ◽  
pp. 149-153 ◽  
Author(s):  
Nasko Terziev ◽  
Geoffrey Daniel ◽  
Ann Marklund
Keyword(s):  
Mechanical Properties ◽  
Picea Abies ◽  
Norway Spruce ◽  
Cell Walls ◽  
Compression Wood ◽  
Morphological Changes ◽  
Mechanical Processing ◽  
Opposite Wood ◽  
Tear Index ◽  
Control Samples

Abstract The aim of the present study was to determine the effect of a variety of abnormal fibres on the mechanical properties of paper made from Norway spruce, Picea abies (L.) Karst. Fibres representing abnormality were obtained from trees treated by irrigation and fertilisation. Moreover, fibres from compression wood and its accompanying opposite wood were isolated. The effect of dislocations on paper quality was studied on four mixtures (20, 40, 60 and 80% fibres with induced dislocations) of untreated/compressed fibres. Two more groups consisting of control untreated samples and samples with 100%-induced dislocations were also included in the test. The mechanical properties of the paper were tested and the results were compared to those of control samples. Abnormal fibres reduced the desired mechanical properties of the final paper concerning tensile strength, modulus of elasticity and tear-tensile index. Irrespective of the type of treatment, all morphological changes introduced in fibre cell walls appear to directly affect changes in the mechanical properties of the paper. Control samples had a tear index of 25 compared to 10 mN m2 g-1 of samples containing 100% dislocations. It is obvious that 20% of dislocations, an amount that is expected to be induced in pulp under mechanical processing and transport, will contribute to a decrease in tear index with an average of 3 mN m2 g-1, i.e., 10% of the total value.

The radial variation of the selected physical and mechanical properties of Norway spruce (Picea abies (L.) H. Karst) wood from the provenance area in Głuchów

2019 ◽  
Vol 105 ◽  
pp. 133-143
Author(s):  
KAROLINA ZAWADZKA ◽  
PAWEŁ KOZAKIEWICZ
Keyword(s):  
Mechanical Properties ◽  
Picea Abies ◽  
Norway Spruce ◽  
Bending Strength ◽  
Physical And Mechanical Properties ◽  
Research Area ◽  
Radial Variation ◽  
Static Modulus ◽  
Spruce Wood ◽  
Static Modulus Of Elasticity

The radial variation of the selected physical and mechanical properties of Norway spruce (Picea abies (L.) H. Karst) wood from the provenance area in Głuchów. Spruce wood (Picea abies (L.) H. Karst) is one of the main species used in building constructions. Due to the wide occurrence, it is important to test various origins and in this way select those with the best material properties. Wood was obtained from one habitat from a provenance experimental area in Głuchów from 40-year-old trees. For the study, trees from three different origins were selected: Nowe Ramuki, Bliżyn and Rycerka Praszywka II (origin from respectively northern, central and southern Poland - seedlings came from these places). Spruce wood from Bliżyn, which is the closest to the proven research area in Głuchów, reached the highest average values in all studied traits (density, ultrasonic wave velocity, dynamic and static modulus of elasticity and static bending strength) and was characterized by the highest variability of these features. Regardless of the origin, the above-mentioned features of the wood showed a clear upward trend going from the pith to the to the side of the trunk.

Lattice Imaging of Grain Boundaries in Ceramics

1977 ◽  
Vol 35 ◽  
pp. 114-115
Author(s):  
D. R. Clarke ◽  
G. Thomas
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Silicon Nitride ◽  
Grain Boundaries ◽  
High Temperature Strength ◽  
Current Interest ◽  
Lattice Imaging ◽  
Special Significance ◽  
Structural Applications ◽  
Refractory Ceramics

Grain boundaries have long held a special significance to ceramicists. In part, this has been because it has been impossible until now to actually observe the boundaries themselves. Just as important, however, is the fact that the grain boundaries and their environs have a determing influence on both the mechanisms by which powder compaction occurs during fabrication, and on the overall mechanical properties of the material. One area where the grain boundary plays a particularly important role is in the high temperature strength of hot-pressed ceramics. This is a subject of current interest as extensive efforts are being made to develop ceramics, such as silicon nitride alloys, for high temperature structural applications. In this presentation we describe how the techniques of lattice fringe imaging have made it possible to study the grain boundaries in a number of refractory ceramics, and illustrate some of the findings.

TEM Studies of Grain Boundary Films in Si3N4 Ceramics

1991 ◽  
Vol 49 ◽  
pp. 930-931
Author(s):  
H.-J. Kleebe ◽  
J.S. Vetrano ◽  
J. Bruley ◽  
M. Rühle
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Silicon Nitride ◽  
Hot Isostatic Pressing ◽  
Amorphous Film ◽  
Liquid Phase Sintering ◽  
Second Phase ◽  
High Temperature Mechanical Properties ◽  
Triple Points ◽  
Boundary Films

It is expected that silicon nitride based ceramics will be used as high-temperature structural components. Though much progress has been made in both processing techniques and microstructural control, the mechanical properties required have not yet been achieved. It is thought that the high-temperature mechanical properties of Si3N4 are limited largely by the secondary glassy phases present at triple points. These are due to various oxide additives used to promote liquid-phase sintering. Therefore, many attempts have been performed to crystallize these second phase glassy pockets in order to improve high temperature properties. In addition to the glassy or crystallized second phases at triple points a thin amorphous film exists at two-grain junctions. This thin film is found even in silicon nitride formed by hot isostatic pressing (HIPing) without additives. It has been proposed by Clarke that an amorphous film can exist at two-grain junctions with an equilibrium thickness.

AEM of reaction-bonded SiC

1992 ◽  
Vol 50 (1) ◽  
pp. 344-345
Author(s):  
K Das Chowdhury ◽  
R. W. Carpenter ◽  
W. Braue
Keyword(s):  
Mechanical Properties ◽  
Phase Transformation ◽  
High Temperature ◽  
Epitaxial Growth ◽  
Liquid Silicon ◽  
Structural Ceramic ◽  
Few Data

Research on reaction-bonded SiC (RBSiC) is aimed at developing a reliable structural ceramic with improved mechanical properties. The starting materials for RBSiC were Si,C and α-SiC powder. The formation of the complex microstructure of RBSiC involves (i) solution of carbon in liquid silicon, (ii) nucleation and epitaxial growth of secondary β-SiC on the original α-SiC grains followed by (iii) β>α-SiC phase transformation of newly formed SiC. Due to their coherent nature, epitaxial SiC/SiC interfaces are considered to be segregation-free and “strong” with respect to their effect on the mechanical properties of RBSiC. But the “weak” Si/SiC interface limits its use in high temperature situations. However, few data exist on the structure and chemistry of these interfaces. Microanalytical results obtained by parallel EELS and HREM imaging are reported here.

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