Heat treatment and mechanics of Moravian Jurassic cherts
Heat treatment and mechanics of Moravian Jurassic cherts
复制标题
摩拉维亚侏罗纪燧石的热处理和力学
DOI：
10.1007/s12520-021-01388-z
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发表时间：
2021
影响因子：
2.2
通讯作者：
P. Schnabl
中科院分区：
文献类型：
--
作者：
Martin Moník;H. Hadraba;D. Milde;Z. Chlup;Z. Nerudová;P. Schnabl
对Moravia(捷克共和国)OlomučAny类型的侏罗纪硅质岩进行了实验热处理，以确定其是否具有更好的剥落性能。使用了压痕测试和其他测试，并与红外(NIR)光谱的变化进行了比较，红外光谱通常指示与材料失水有关的机械变化。由于压痕拐角处裂纹的不规则扩展，压痕测试提供了模糊的结果。另一方面，三点载荷断裂和共振试验表明，硅质岩在加热到300°C后，断裂韧性降低，弹性模数增加，剥落效果最好。这两个变化相辅相成：第一个变化导致更容易剥落，另一个更稳定的裂纹扩展和可预测性。流体包裹体的同时形成可能有助于更快的裂纹扩展。正如我们的序列统计分析所显示的，断裂韧性的下降似乎是一个更渐进的过程，而在300°C时硬度的增加是相当突然的。在东欧的史前，奥洛木č任何硅质岩或其他细粒岩性都没有经过热处理，这一事实表明，与更西边的地区不同，史前时期这一地区并没有通过热处理进行改进。这可能是由于远距离进口其他更细颗粒的岩性，这是自公元前4万年以来该地区经常使用的一种策略。
Experimental heat treatment was applied to Moravian (Czech Republic) Jurassic cherts of Olomučany type to find whether it leads to better flaking properties. Indentation tests and other tests were used and compared with the changes in infrared (NIR) spectra which are usually indicative of mechanical changes linked with water loss from the material. The indentation tests provided ambiguous results due to irregular propagation of cracks from indent corners. On the other hand, three-point-load fracturing and resonance tests were usable and indicated that the cherts are best flakeable after heating to 300 °C when fracture toughness is reduced whereas elastic modulus increases. These two changes complement each other: The first causes easier flakeability and the other more stable crack propagation and predictability. The simultaneous formation of fluid inclusions probably contributes to swifter crack propagation. As shown by our sequence statistics analysis, the drop in fracture toughness seems to be a more gradual process, whereas the increase in stiffness at 300 °C is rather sudden. The fact that the Olomučany chert or other fine-grained lithologies were not heat-treated in the prehistory of eastern Central Europe indicates that the improvement by heat treatment was not practised in this area in prehistory, unlike in more westerly regions. This may be due to long-distance imports of other, finer-grained lithologies, a strategy frequented in the region since 40,000 BCE.
旧石器时代石器材料的显微硬度分析和表征，以了解主要材料的选择和利用
DOI：
--
发表时间：
2009
期刊：
Materials Characterization 60
影响因子：
--
作者：
Kazuki Ueno;et. al.;Kaoru Yonekura
通讯作者：
Kaoru Yonekura