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ballack315629

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[求助] 弱问,理论密度theoretical density 是不是就是真密度true density

弱问,理论密度theoretical density 是不是就是真密度true density。 球磨后用Helium pycnometry测出的密度,是不是就是理论密度。[ Last edited by ballack315629 on 2012-4-15 at 19:29 ]
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朗月星辰

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Absolute powder density: The mass of powder per unit of absolute volume
Apparent particle density: The mass of a particle divided by its apparent (particle) volume
Apparent powder density: The mass of a powder divided by its apparent volume
Bulk density: (also called Bulk powder density): The apparent powder
density under defined conditions .
The mass of the particles divided by the volume they occupy that includes
the space between the particles
The ratio of the mass of a collection of discrete pieces of solid material to
the sum of the volumes of: the solids in each piece, the voids within the
pieces, and the voids among the pieces of the particular collection

Effective particle density: The mass of a particle divided by its volume
including open pores and closed pores

Envelope density: The ratio of the mass of a particle to the sum of the
volumes of: the solid in each piece and the voids within each piece, that is,
within close-fitting imaginary envelopes completely surrounding each piece

The ratio of the mass of a particle to the envelope volume of the particle

Skeletal density: The ratio of the mass of discrete pieces of solid material
to the sum of the volumes of: the solid material in the pieces and closed (or
blind) pores within the pieces

Tap density (also called Tap powder density): The apparent powder
density obtained under stated conditions of tapping

Theoretical density: The ratio of the mass of a collection of discrete
pieces of solid material to the sum of the volumes of said pieces, the solid
material having an ideal regular arrangement at the atomic level

True density (also called True particle density); The mass of a particle
divided by its volume, excluding open pores and closed pores
11楼2012-10-27 19:42:36
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封神之神

至尊木虫 (职业作家)


ballack315629(金币+1): 谢谢参与
dengwei_19: 专家考核 2012-05-01 23:59:33
个人认为不是一个意思
理论密度是通过理论计算得出的
真密度是测试得出的
虽然两者数值应该比较接近,但是仍然会有误差,原因和测试过程以及制样过程,微观结构有关
2楼2012-04-13 22:31:26
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csuxiangbo

铜虫 (小有名气)

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ballack315629(金币+1): 谢谢参与
tjcdp: 金币+1, 鼓励交流,言之有理! 2012-04-21 17:51:01
zhangquan8385: 回帖置顶 2012-04-23 07:57:04
肯定回答:不是一回事,理论密度是按照理想状态下的晶体结构,在X射线衍射探测到的材料密度,也就是它所能达到的最大密度。实际密度往往是通过水测法,油浸法,其实都是依据阿基米德原理来测,需要测量其饱和质量,悬浮重量,干重。来计算其密度,当然通过计算重量,几何体积得到的就是几何密度。
3楼2012-04-14 00:03:29
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朝歌屠叟

铁杆木虫 (正式写手)

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ballack315629(金币+1): 谢谢参与
tjcdp: 金币+1, 鼓励热心回复! 2012-04-21 17:51:20
zhangquan8385: 金币+1, 鼓励 2012-04-23 07:57:43
zhangquan8385: 回帖置顶 2012-04-23 07:57:46
首先,理论密度和真实密度完全不一样。
其次,你所说的Helium pycnometry是怎么操作的,能说具体一点吗。

陶瓷材料密度有如下几种表示:
1. 结晶学密度。指由原子组成的没有缺陷的连续晶格计算出来的理想密度。
2. 理论密度。与结晶学密度同义,但考虑了固溶体和多相。
3. 体积密度。陶瓷体实际测出的密度,包括陶瓷内部所有的晶格缺陷,各种相组成和制造中形成的气孔。
4. 相对密度。指陶瓷实测体积密度与其理论密度比值的相对百分数。
前两种密度是指陶瓷材料内没有缺陷的理想情况,意味着制造过程形成的气孔为零,所以在结构内的原子间只有间隙。
在制造中形成的缺陷和气孔的情况下,通常使用体积密度或相对密度。

结晶学密度或理论密度可以从晶体结构数据(晶胞参数)和所含元素的相对原子质量通过计算得到。

对于坯体的体积密度测量:
烧结后的陶瓷体体积密度通常采用排水法,按阿基米德定律计算出来。
烧结前的陶瓷素坯用排汞法测量。
4楼2012-04-14 05:34:18
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