6.2.4 Ceramic sintering
Hello, everyone, today we are going to talk about ceramic sintering.
译文：
大家好，今天我们要讲的是陶瓷烧结。
Becau of their high melting point, hardness，and brittleness, ceramic components cannot be made by the fabrication routes ud with metals and polymers. The Main method for preparing ceramic is Sintering, Feedstock is usually available as a powder. Powder as raw materials would affect the final properties of products, so powder handling and powder processing are required. 陶瓷由于本身高熔点，硬和脆，制备方法与金属和聚合物不同。主要方法是烧结和粉体喂料方式。由于粉体为原料可能影响产品最终性能，因此有必要对粉体进行处理。
译文：
陶瓷由于本身高熔点，硬和脆，制备方法与金属和聚合物不同。主要方法是烧结和粉体喂料方式。由于粉体为原料可能影响产品最终性能，因此有必要对粉体进行处理。
Now look at this picture, The key steps are following: Powder Synthesis, Powder Handling, Green Body Formation, Sintering of Green Body, Final Machining and Asmbly.
译文：
现在看这张图，关键步骤如下：粉体合成、粉体处理、生坯形成、生坯烧结、最终加工和装配。
A major problem in ceramic processing is achieving the same properties every time when a process is repeated. Intelligent processing of materials is an attempt to solve the problem of making complex materials to get more uniform in their structure and properties. Some industry have an ongoing program to automate quality control that allows quality to be built in during processing by ceramic powder and powder handing.
陶瓷处理的一个主要问题是在每次重复的过程中都要达到相同的属性。材料的智能化处理是解决复杂材料在结构和性能上的统一问题的一种尝试。一些企业在利用自动化控制质量，以达到在陶瓷粉末以及粉末处理过程中建立质量品质。
In the initial preparation of ceramic materials for shaping into some uful products the raw ceramic materials must first be reduced to a powder form. 在陶瓷成型过程，必须首先降低陶瓷原料粉体的粒径。
译文：
在陶瓷原料的最初制备过程中，必须先将陶瓷原料加工成粉末。
Ceramic powders are typically in the size range 0.5 - 5.0 μm. Natural materials such as clays are weathered mineral powders of this size mixed with water. Traditional ceramics are made from treated mixtures of clays. Advanced ceramic powders are synthesized. About powder handling, often a liquid suspension stage followed by drying. Dried powders are then compacted to form a “green body” before firing. 天然材料比如粘土是不同粒径颗粒与水混合的风化矿物粉末。传统陶瓷就是由黏土处理的混合物制成的。工程陶瓷粉体是人工合成。关于粉末处理，通常是由制成液体悬浮液，然后干燥，干粉在烧结前会被压成一个生坯。注意，green body是生坯的意思。注意，green body是生坯的意思。
译文：
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陶瓷粉末粒径一般在0.5-5.0微米范围内。天然材料比如粘土是不同粒径颗粒与水混合的风化矿物粉末。传统陶瓷就是由黏土处理的混合物制成的。工程陶瓷粉体是人工合成。关于粉末处理，通常是由制成液体悬浮液，然后干燥，干粉在烧结前会被压成一个生坯。注意，green body是生坯的意思。
巨大的反义词
In the initial preparation of powders, comminution describes the operations of crushing and grinding. Crushing reduces the raw material to particle size, Grinding further reduces the particle-size ceramic to a powder form.
在粉末的初始制备中，粉碎操作描述了碾碎和研磨的过程。碾碎将原料减少到颗粒大小，研磨进一步将颗粒大小的陶瓷研磨成粉末。青少年脱发怎么办
Grinding is accomplished by confining the ceramic powder along with extremely hard balls, pebbles, or rods in a revolving, cylindrical drum called a ball mill. This grinding action caus the reduction to a fine powder by a combination of impact and attrition. Often water is added to the powder which changes into a slurry. The hard balls and pebbles are known as media. 这里，Crushing是碾碎，Grinding是研磨，是将陶瓷粉和硬的球，鹅卵石，或棒在筒状机中旋转，我们称之为球磨。这个球磨通过冲击和摩擦，将粉体变成细粉。通常加入水加入到粉体中形成泥浆。硬球和鹅卵石被称为介质。获得合适的粉体原料后，下面就要进行烧结。
译文：
这里，Crushing是碾碎，Grinding是研磨，是将陶瓷粉和硬的球，鹅卵石，或棒在筒状机中旋转，我们称之为球磨。这个球磨通过冲击和摩擦，将粉体变成细粉。通常加入水加入到粉体中形成泥浆。硬
随心所欲拼音球和鹅卵石被称为介质。获得合适的粉体原料后，下面就要进行烧结。山药骨头汤的做法
Sintering, Densification, or firing, is a process by which a particulate compact is transformed into a ceramic part that has adequate properties to satisfy the needs of a specific application.
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烧结、致密化或燃烧，是指将一种颗粒状致密物转化成陶瓷部件，使其具有足够的性能，以满足特定应用的需要。
Sintering is the any changes in shape which a small particle or a cluster of particles of uniform composition undergoes when held at high temperature. So sintering is a complex phenomenon in which veral process are occurring simultaneously. When sintered at high temperatures, usually between 1000o C to 2000o C, the particles fu to become a solid material with properties superior to many metals. In sintering, the
powder compact is heated at a temperature below the melting temperature of its components. 烧结是一个复杂的过程。当在高温下烧结，通常为1000o C to 2000o C 时，这些粒子融合成一种固体物质，其性能优于金属。在烧结中压坯加热温度要低于组元的熔点。
港台经典歌曲译文：
王晶莹>轴端挡圈烧结是指在高温下，小颗粒或一团均匀成分颗粒的形状发生的变化。烧结是一个复杂的过程。当在高温下烧结，通常为1000o to 2000o C时，这些粒子融合成一种固体物质，其性能优于金属。在烧结中压坯加热温度要低于组元的熔点。
Sintering process can be considered as a variety of mechanisms. First, remove the initial pores, cond cau the growth of grains and then strong bonding forces to provide strength to a powder compact.
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烧结过程可被认为有多种机制，首先是去除最初的气孔，其次是颗粒的生长，然后是大的结合力为压坯提供了强度。
Sintering can occur in the prence or abnce of a liquid pha. When some liquid is formed during processing, we call it liquid-pha sintering. In the abnce of a liquid pha, the process is referred to as solid-pha sintering. 烧结过程如果有液相存在，叫液相烧结，如果没有液相，则固相烧结。
译文：
烧结过程如果有液相存在，叫液相烧结，如果没有液相，则固相烧结。
The main driving force in sintering process is the reduction in surface area. It can be done through the following two paths. Look at this picture. Firstly, it can happen by the elimination of solid/vapor interfaces and the creation of grain boundary area, followed by grain growth, which leads to densification. Secondly, reduction of the total surface area by an increa in the average size of the particles, which leads to coarning. 烧结过程主要驱动力是减少表面积。它可通过以下两个路径进行，一是消除固汽界面和形成晶界，随后晶粒生长，导致致密化。另外通过颗粒粗化，平均晶粒尺寸
增加而使表面积减少。
译文：
烧结过程主要驱动力是减少表面积。它可通过以下两个路径进行，一是消除固汽界面和形成晶界，随后晶粒生长，导致致密化。另外通过颗粒粗化，平均晶粒尺寸增加而使表面积减少。.。
The two mechanisms are usually in competition. If the atomic process that lead to densification dominate, the pores get smaller and disappear with time and the compact shrinks. 如果原子致密化过程占主导地位，则随着时间的推移，气孔就会变小和消失，坯体收缩。
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如果原子致密化过程占主导地位，则随着时间的推移，气孔就会变小和消失，坯体收缩。
Ceramic requires strength, and strength comes with a homogeneous microstructure that has a fine grain structure. What the problem for the final density reached？The initial pores between the original particles have not been completely eliminated.
译文：
陶瓷需要强度，而强度则是由一种均匀的微观结构构成的。要达到最终密度的问题是什么? 是原始粒子间的初始气孔没有完全消除。
Sintering furnaces usually heat ceramic compacts externally by radiant and convection thermal transfer. 烧结炉加热陶瓷外部主要是通过辐射和对流进行热传递。
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烧结炉加热陶瓷外部主要是通过辐射和对流进行热传递。
There is a Figure in comparison with the effects of sintering alumina and zirconia using microwave sintering versus standard furnace heating. It shows that by microwave sintering, the density of Alumina can attain to about 90% with only 1200o C. But it is
