Judge dark-red enameled pottery sintering method

Judge dark-red enameled pottery sintering method

How to determine the sintering dark-red enameled pottery? The expert points out, the sintering, judge dark-red enameled pottery from shallow and deep, roughly into four kinds of methods, is view color, listening, debate inside and outside, check complex.
A, view color
Clay is less, the higher the sintering temperature. But some of purple material reaches a certain high temperature occurs after further chemical reaction, appear coking phenomenon, produce pin holes and bubble. From low melting things begin to melt to appear bubble, stythe eye of a needle, coking phenomenon the critical temperature range, is called sintering (temperature) range. With the increase of firing temperature, low melting things begin to melt, and at the same time, the amount and nature of the metal oxide also is in produce change. As a powder metalresult of the metal oxide few quantity and type is dark-red enameled pottery color material, so with the change in temperature, dark-red enameled pottery color effect will also be different, will not only from shallow darker, and some pug fever product color will be different. Those who need a specification is, how many kinds of metal oxide, apart from the firing temperature on outside, still and firing atmosphere related. When burning oxygen and carbon monoxide gas concentration is different, the formation of metal oxide will be different, thus decided to burn product color.

Second, listening
This is the most common method. Listen to the sound, 1, listen to the voice of grinding, 2, listen to the voice of stroke. Grinding, even with a pot cover mouth on lap type grinding; Stroke, is left hand should be under pitcher body mold, the right hand carry pot son (cover button), with the top of the lid tapping pot Pan (put). Listen to the sound, judgment is the body's density, also is in the body how much porosity. Purple is mainly based on quartz content and clay content and clay in metal oxide content type and many little to classification. Does not contain the quartz, or quartz content is very few, mud, otherwise it is sand. Mud fe content is more red clay, iron content rarely (or not) is white mud. In sand, clay, clay less little iron oxide (and iron ion), and titanium oxide more is this mountain lu (in fact for sand, similarly hereinafter). Iron content is less period of mud (sand). Quartz, clay matching moderate, clay of the iron content is less, is zhu mud (sand), iron content is more purple clay (sand).

Third, both inside and outside to contend
Dark-red enameled pottery color except decided to pug species outside, still and firing technology closely related. In oxidizing atmosphere, violet arenaceous mud of iron formation is rufous iron oxide red, in reducing atmosphere formation is sintered metalyoung black oxidation and iron. Purple clay, red mud (z mud) made dark-red enameled pottery color, it is by the relative amount of the decision. Firing atmosphere is refers to the combustion environment oxygen, carbon monoxide gas concentration level. In the same firing temperature (of course must be sintering temperature above), oxygen is more, is oxidation atmosphere; Carbon monoxide much gas, is reducing atmosphere. Obviously, the same conditions, always body surface oxygen concentration is high, the body internal carbon monoxide gas concentration is high, then, sintering dark-red enameled pottery of the surface is red, purple, but section but color is deeper, even a young black. Then, to observe dark-red enameled pottery pot body color difference in size, will become judgment dark-red enameled pottery sintering degree of a a universally, which will never change at all times and in all over the standard.