The core competitiveness of silicon nitride bricks lies in their uniform and dense microstructure and stable physical and chemical properties. The density and density uniformity of the green body are entirely dependent on precise control during the forming stage - the forming process must meet five core requirements: uniform density, dense structure, no cracks, intact edges and corners, and no damage to the activity of the particles. It is necessary to ensure uniform density throughout the green body, with the final product's bulk density controlled at 3.1-3.3g/cm³ and the apparent porosity ≤12%, laying a solid foundation for subsequent high-temperature sintering. At the same time, it is necessary to avoid the agglomeration of silicon nitride particles and the stratification of raw materials during the pressing process to prevent structural porosity, crack propagation, and spalling after sintering. The pressing speed and holding time must also be precisely controlled to accommodate the fine particles, poor fluidity, and difficult gas expulsion of the silicon nitride mixture, avoiding internal gas pores in the green body that could lead to structural failure during high-temperature service. Additionally, the activity of the silicon nitride particles must be protected to prevent oxidation and affect the corrosion and high-temperature resistance of the product. Moreover, the forming pressure requirements for different specifications of silicon nitride bricks must be precisely matched to avoid over-pressing damage and under-pressing porosity. Currently, the technical shortcomings of traditional forming equipment have led to common problems in the production of silicon nitride bricks, such as uneven density, green body cracking, edge and corner damage, large dimensional deviations, and low product qualification rates, seriously restricting the industrialization of high-end silicon nitride bricks. Zhengzhou Haloong, relying on the third-generation permanent magnet synchronous servo direct drive core technology, has optimized and upgraded the HLDS series of CNC servo screw presses, specifically addressing the forming pain points of silicon nitride bricks and creating dedicated forming equipment. With the core advantages of precise pressure control, flexible pressure transmission, and intelligent adaptation, it has established a benchmark for high-end silicon nitride brick quality.

Compared to ordinary refractory bricks, the forming difficulty of silicon nitride bricks increases exponentially due to the characteristics of the raw materials and performance requirements. The mixture is composed of silicon nitride coarse powder, fine powder, and sintering aids in precise proportions, with fine particles, large specific surface area, extremely poor fluidity, and difficult gas expulsion. Moreover, silicon nitride particles are hard, brittle, and prone to oxidation, making it easy to experience particle agglomeration, micro-cracks in the green body, edge and corner damage, and surface oxidation during the forming process. The precision requirements for the application force, pressing speed, and holding time are extremely strict - it is necessary to achieve green body densification through precise pressing and ensure the uniform dispersion of silicon nitride particles, while avoiding green body cracking and edge and corner damage caused by rigid impact. At the same time, the air in the mixture must be efficiently expelled to prevent residual pores from affecting the product's thermal shock resistance and corrosion resistance. The temperature fluctuations during the pressing process must also be controlled to prevent the oxidation and deterioration of silicon nitride particles. Moreover, it is necessary to adapt to the differentiated forming requirements of different specifications and uses of silicon nitride bricks.

Zhengzhou Haloong has deeply studied the raw material characteristics, forming process logic, and industry upgrade demands of silicon nitride bricks. With the core technology of permanent magnet synchronous servo motor direct drive + static pressure flexible pressure transmission + intelligent CNC system, it has specifically optimized the HLDS series of servo screw presses, comprehensively upgrading the equipment's precision, stability, and adaptability. The advantages precisely match the forming requirements of silicon nitride bricks, making it the preferred equipment for mass production of high-quality silicon nitride bricks and assisting refractory material enterprises in creating high-quality products suitable for high-temperature, strong corrosion, and strong impact working conditions, seizing the opportunity in the high-end market.

Equipped with a core permanent magnet synchronous servo motor direct drive system, it completely eliminates the inefficient transmission structures such as traditional friction discs and clutches, with an extremely short transmission chain and zero energy loss during energy transmission. The pressure output is stable and controllable throughout the process. The equipment is equipped with Haloong's independently developed CNC pressure control module for silicon nitride bricks, which can digitally and precisely set the striking energy, pressing speed, stepwise pressing times, and holding time. The energy repetition control accuracy is ≤±1%, ensuring that the forming pressure is highly consistent in each process, completely eliminating quality deviations caused by manual operation and mechanical fluctuations. In response to the fine particle size, difficult exhaust, and easy agglomeration characteristics of silicon nitride mixed materials, a customized stepwise flexible pressurization process has been developed. This process first applies light pressure to loosen the raw materials and slowly expel the residual air inside, then gradually and steadily pressurizes layer by layer, and finally maintains long-term pressure to shape the product. This ensures that all parts of the green body, including the center, edges, and corners, are uniformly stressed, with density fluctuations controlled within a very small range. At the same time, it effectively prevents the agglomeration of silicon nitride particles and the stratification of raw materials, protects the activity of silicon nitride particles, and provides a solid foundation for the uniform combination of the bonding phase during subsequent high-temperature sintering, increasing the product qualification rate to over 99%.

The equipment adopts a fully enclosed static pressure screw, nut, and dedicated heavy-duty bearing transmission structure. During operation, a stable high-pressure oil film is formed for protection, achieving flexible and uniform pressure application and gradual pressurization. This completely avoids the severe impact force and stress concentration problems caused by traditional rigid pressurization. The pressurization process is smooth and gentle, with uniform and soft pressure transmission. It can not only fully expel the internal pores of the green body and disperse the agglomeration of silicon nitride particles, completely eliminating defects such as porosity, stratification, and micro-cracks, but also gently protect the activity of silicon nitride particles, prevent the cracking and corner damage of the green body, significantly reduce the waste of high-cost raw materials, and effectively extend the service life of the mold, reduce material costs, and improve the production efficiency of the enterprise.

Breaking through the structural limitation of the fixed lower dead point in traditional equipment, a stepwise forging forming mode is adopted. According to the material, size, structural complexity (such as aviation-shaped parts, nozzle bricks, lining bricks), and density requirements of silicon nitride bricks, the stroke of the slider, the pressurization depth, and the applied pressure can be flexibly adjusted to precisely match the forming requirements of various types of silicon nitride bricks, covering the full range of production scenarios for high-end refractory materials and structural ceramics. There is no need to worry about the problems of uneven pressurization caused by deviations in raw material filling volume, particle size distribution differences, and changes in the fluidity of the mixed materials. Combined with a rapid mold change system, mold changes are convenient and efficient, perfectly adapting to the flexible mode of multi-variety and batch production, meeting the batch supply needs of high-end fields such as aerospace and semiconductors.

The equipment is equipped with a dedicated forming parameter database for silicon nitride bricks, integrating the optimal forming process parameters for various specifications, different raw material ratios, and different density requirements of silicon nitride bricks, including common products such as standard silicon nitride bricks, shaped silicon nitride components, and high-strength corrosion-resistant silicon nitride bricks. Operators can retrieve them with one click, eliminating the need for repeated debugging and exploration, and significantly reducing the interference of human factors on product quality. All forming parameters can be permanently saved and reused in batches, ensuring that the density, porosity, and dimensional accuracy of each batch and each product are highly consistent, with uniform dispersion of silicon nitride particles and effective prevention of particle oxidation, easily meeting the strict quality requirements of high-end fields at home and abroad, and helping enterprises smoothly open up overseas high-end refractory materials and structural ceramics markets.

Compared with traditional friction presses, the Haloong servo screw press adopts an on-demand start-stop and sleep energy-saving intelligent mode. The servo motor only operates during the pressing process, and the standby state is completely zero energy consumption, with a comprehensive energy-saving rate of over 55%, significantly reducing the electricity cost of silicon nitride brick production, meeting the green and low-carbon development needs of the refractory materials and structural ceramics industry. At the same time, the static pressure transmission structure has minimal wear, combined with a fully automatic forced lubrication system and an oil shortage alarm device, achieving maintenance-free operation, with a low equipment failure rate and a service life far exceeding that of traditional equipment, reducing the later maintenance cost by more than 40%, comprehensively compressing production, maintenance, and material costs, and helping enterprises achieve a green, low-carbon, and efficient profit-making production model.

The equipment is equipped with standardized industrial communication interfaces, which can be seamlessly linked with automatic and precise feeding machines, closed-loop distribution machines, intelligent demolding machines, non-destructive testing equipment for green bodies, and constant-temperature conveyor lines, building a fully automated and intelligent forming production line for silicon nitride bricks, achieving unmanned control throughout the process from distribution, pressing, pressure maintenance, demolding to green body transfer and inspection, minimizing human intervention. This not only avoids damage to the green body caused by manual operation but also ensures forming accuracy and production efficiency. It supports remote monitoring, parameter debugging, fault early warning, and production data traceability functions, facilitating domestic and foreign customers to manage production progress and product quality in real time from different locations. It fully conforms to the global trend of intelligent, digital, and green transformation in the refractory and structural ceramics industry, and helps enterprises build an intelligent production base for high-end silicon nitride bricks.

Zhengzhou Haloong Machinery Co., Ltd., as a leading enterprise in the domestic electric servo screw press field, has been focusing on technological innovation in refractory forming equipment for 45 years. It has been deeply engaged in solving the forming process pain points of high-end refractories such as silicon nitride bricks and structural ceramics. It adheres to customizing technology to empower industrial upgrading. The Haloong HLDS series of CNC servo screw presses cover the full tonnage range from 200T to 1600T. According to the material, specifications, production capacity, density, and raw material ratio requirements of customers' silicon nitride bricks, it provides one-to-one customized forming solutions, fully meeting the mass production needs of various silicon nitride bricks and adapting to the supply of refractories in different high-end high-temperature, strong thermal shock, and strong corrosion fields.