Mingbai Machinery Tool Successfully Develops "Gradient Composite Substrate" Slitter Shear Blade, Achieving Both Toughness and Wear Resistance

Recently, the R&D center of Mingbai Machinery Tool Technology Co., Ltd. announced a significant technological breakthrough. After nearly a year of repeated trials and process optimization, the company has successfully developed a slitter shear blade with a "gradient composite substrate" structure, which has now entered small‑batch production. This technology creates a gradient change in composition and microstructure from the core to the surface within the same blade, enabling the blade to simultaneously possess a high‑toughness core and a high‑wear‑resistant working layer. It completely resolves the long‑standing contradiction of traditional homogeneous material blades – "high hardness leads to brittleness, while good toughness results in poor wear resistance." According to internal tests and customer trials, the gradient composite substrate slitter shear blade achieves a 120% increase in service life compared to conventional blades when slitting high‑strength stainless steel and silicon steel, while impact resistance is improved by more than three times.

From "Single Material" to "Gradient Composite"

Traditional slitter shear blades are usually made from a single grade of tool steel or high‑speed steel. To achieve high wear resistance, the material hardness is often increased, but toughness decreases, leading to chipping when slitting thick plates or encountering hard spots. If toughness is prioritized by lowering hardness, the cutting edge wears out too quickly. Moving beyond the single‑material mindset, the Mingbai R&D team proposed a "gradient composite" design concept. The blade core uses a high‑toughness material to ensure impact resistance. The surface and cutting edge use a high‑wear‑resistance material to guarantee service life. Between them, a gradient transition layer with gradually changing composition and microstructure is set to eliminate interfacial stress caused by abrupt property changes.

Powder Metallurgy + Diffusion Sintering to Achieve Gradient Structure

The core of this technology lies in a special powder metallurgy diffusion sintering process. The R&D team fills a mold with two different metal powders in a layered gradient pattern – low‑carbon high‑toughness alloy powder for the core, and high‑carbon high‑wear‑resistance alloy powder for the surface. After high‑temperature, high‑pressure diffusion sintering, a gradient layer with continuously changing composition and a seamless microstructure transition is formed between the two layers, rather than a sharp interface. The resulting material is then forged, rolled, heat treated, and precision ground to produce the finished blade. Tests show that the gradient composite blade has a core hardness of 48‑52 HRC and impact toughness exceeding 80 J/cm². The surface hardness reaches 62‑65 HRC, equivalent to that of high‑alloy tool steel. The gradient transition layer is approximately 2‑3 mm thick, with no cracks or spalling defects.

Impressive Test Data: Both Hard and Tough

In internal bench tests, the gradient composite slitter shear blade continuously slit 6 mm thick 304 stainless steel plates for 8 hours without edge chipping, and the wear amount was only 60% that of a conventional high‑hardness blade. In impact load tests, the blade could withstand three times the impact energy of a conventional blade without fracture. Even more encouraging were the customer trial results. A transformer core processing enterprise used the gradient composite silicon steel shear blade to slit high‑grade oriented silicon steel. The blade remained free of chipping for two consecutive weeks, whereas the previously used imported blade chipped on average every five days. The customer's production manager said, "Mingbai's blade truly solved our pain point. The frequency of blade changes has dropped significantly, and production efficiency has noticeably increased."

Controlled Cost and Scalable for Mass Production

Compared with traditional powder metallurgy homogeneous high‑speed steel blades, the gradient composite substrate blade uses expensive wear‑resistant alloy powder only on the surface layer, while the core uses lower‑cost high‑toughness alloy powder. Overall material cost is reduced by approximately 20‑30%. Furthermore, this process can be applied to slitter shear blades, circular knives, and custom‑shaped blades of various specifications, offering good scalability. Mingbai has filed a national invention patent for this technology and plans to achieve mass production within the year, promoting it to industries such as metal processing, transformer core manufacturing, and new energy battery electrode slitting.

Continuous Innovation, Leading Material Technology Upgrades

The company's R&D director said, "The gradient composite substrate represents an important original exploration by Mingbai in blade material technology. We are no longer limited to selecting a single steel grade; we can now 'tailor' the internal microstructure distribution of the blade according to the customer's working conditions. In the future, Mingbai will continue to delve into materials science, providing customers with more blade products that combine high performance and high cost‑effectiveness." The company's general manager emphasized that Mingbai will adhere to technology‑driven development and promote China's precision blade industry to a higher level through original innovation.

Website: www.mingbaiblade.com