In the research and development stage of new special ceramic products, mold opening often costs tens of thousands of yuan and takes several weeks, which often becomes a hurdle for engineers. Tao " high wall " . If the product design still requires later iterations, the early mold fees will most likely be wasted. In order to solve this pain point, the field of special ceramics has vigorously promoted " None Mold quick prototyping " technology. This can not only help companies save a lot of mold opening costs, but also shorten the development cycle from weeks to days. At present, the mainstream and mature mold-less proofing solutions in the industry are mainly divided into " Additive Manufacturing ( 3D Print) " with " Subtractive manufacturing ( Precision machining) " Two major schools.

School One: Special Ceramics 3D Print

3D Printing is real " No mold " technology through computers CAD The model directly drives the equipment and is stacked layer by layer. This is the only option for ceramic parts with extremely complex structures, internal hollow dimples, flow channels or topologically optimized structures. Current industrial grade special ceramics 3D There are two main mainstream technologies for printing.

1. Light curing molding

Ceramic powder is mixed into photosensitive resin in a high proportion to prepare ceramic slurry. UV light is used to irradiate and cure layer by layer to form " Blank before degluing " , and finally undergoes high-temperature debinding and sintering.

• Advantages: The surface finish is extremely high, almost comparable to mold molding. High dimensional accuracy, usually up to ±0.05 mm , very suitable for making micro and precision ceramic parts.

• Applicable materials: alumina, zirconia, etc.

2. selective laser sintering

Solidified ceramic powder or powder mixed with a binder is directly scanned using a high-energy laser beam.

• Advantages: Fast production speed, suitable for manufacturing medium and large structural parts.

• Applicable materials: Silicon carbide, silicon nitride and other ceramic materials with extremely high covalent bond hardness and difficult to process with light curing.

School Two: Ceramic Green Body / Precision machining of cooked blanks

If the parts you are prototyping have relatively regular structures, such as porous plates, shafts, sleeves, flanges, etc., but have extremely high requirements on material performance (density, strength), then using existing standard blocks for machining is the fastest and lowest cost prototyping method. According to the location of the ceramic during processing " Status " , divided into two routes:

1. green body / Ceramic pre-sintered body (porcelain block) processing ——" Soft first and then hard "

After the ceramic powder is press-formed and before it undergoes the last step of high-temperature full sintering (at this time, the ceramic is like chalk, with low hardness and easy to cut), directly use a standard CNC machine tool ( CNC ) for turning, milling and drilling. • Advantages: fast processing speed, small tool wear, and very low cost.

• Difficulty: Due to the severe volume shrinkage of the green body during the subsequent high-temperature sintering process (usually the shrinkage rate is within 15% ~ 25% between), so it is necessary to rely on extremely accurate dimensional shrinkage enlargement calculations. If the manufacturer is inexperienced, the size of the sintered finished product can easily exceed tolerances.

2. Precision hard machining of cooked blanks (fully sintered ceramics) ——" head-on "

Directly take the standard special ceramic plates or rods that have been sintered at high temperature and completely densified, and use diamond tools, ultrasonic processing or laser engraving for fine material reduction. • Advantages: No sintering shrinkage problem, extremely high dimensional accuracy and geometric tolerance (up to micron level μm ), without any discount on material performance.

• Applicable scenarios: high-purity alumina, pressure-sintered silicon nitride, tough zirconia, etc. For a small amount of samples, just buy ready-made bar stock and let the master process it with a diamond grinding wheel. Usually, you can get the sample in a few days.

How to choose? " Tooling-Free Prototyping " Decision guide

In actual research and development, you can refer to the following vivid comparison dimension to determine which mold-less proofing technology is used: