霸刀分享-浅谈立方氮化硼超硬刀具材料
立方氮化硼（CBN）是一种硬度仅次于金刚石的人工合成超硬材料，因其卓越的热稳定性和对铁系金属的化学惰性，成为加工淬硬钢、高硬度铸铁等黑色金属难加工材料的首选刀具方案。
背景
立方氮化硼（Cubic Boron Nitride, CBN）是20世纪50年代由美国通用电气公司（GE）在高温高压条件下人工合成的。它的出现填补了金刚石刀具在加工铁族金属时易发生化学反应（如扩散和催化转化）而导致快速磨损的空白。CBN与金刚石并称为“超硬材料”，广泛应用于现代机械制造中对高硬度、高强度材料的精密和高效切削。
性能优势
CBN刀具的核心竞争力源于其独特的物理化学性能：
极高的硬度与耐磨性：CBN的硬度可达8000~9000 HV，仅次于金刚石，远高于硬质合金和陶瓷刀具，使其在加工高硬度材料时具有超长的刀具寿命。
优异的热稳定性：CBN的耐热温度高达1400~1500℃，是所有刀具材料中最高的，而金刚石在700~800℃就开始氧化或石墨化。这使得CBN刀具非常适合高速切削和干式切削。
出色的化学稳定性：CBN与铁、镍、钴等铁族金属在1200~1300℃下不发生明显的化学反应，有效避免了刀具的粘结和扩散磨损，这是它能成功加工钢铁类材料的关键。
良好的导热性：CBN的导热系数仅次于金刚石，有助于快速传导切削区产生的热量，降低刀尖温度，保护刀具和工件。
分类与形式
CBN刀具主要分为两大类：
整体聚晶立方氮化硼（PCBN）刀具：整个刀片均为CBN材料，无中心孔，通常需专用刀杆，适合大切深、重载荷的断续切削。
焊接式PCBN刀具：将CBN材料作为切削刃，焊接在硬质合金基体上，有中心孔，可与标准刀杆通用，经济性好，适用于精加工和半精加工。
立方氮化硼（CBN）凭借其高硬度、高热稳定性和对铁族金属的化学惰性，已成为现代制造业中加工高硬度黑色金属不可或缺的超硬刀具材料。 它不仅实现了“以车代磨”的工艺革新，大幅提高了生产效率和加工精度，还在航空航天、汽车制造、国防军工等高端制造领域发挥着关键作用。随着国产化进程加速，中国企业在CBN刀具市场也正占据越来越重要的地位。
A Brief Discussion on Cubic Boron Nitride Super-hard Cutting Tool Materials
Cubic boron nitride (CBN) is a synthetic super-hard material with a hardness second only to diamond. Due to its outstanding thermal stability and chemical inertness to iron-based metals, it has become the preferred tool solution for machining difficult-to-machine ferrous metals such as hardened steel and high-hardness cast iron.
Background
Cubic Boron Nitride (CBN) was artificially synthesized by General Electric Company (GE) of the United States under high temperature and high pressure conditions in the 1950s. Its emergence fills the gap that diamond tools are prone to chemical reactions (such as diffusion and catalytic conversion) when processing iron group metals, which can lead to rapid wear. CBN, along with diamond, is known as a "super-hard material" and is widely used in modern mechanical manufacturing for precise and efficient cutting of high-hardness and high-strength materials.
Performance advantage
The core competitiveness of CBN cutting tools stems from their unique physical and chemical properties:
Extremely high hardness and wear resistance: The hardness of CBN can reach 8000 to 9000 HV, second only to diamond and far exceeding that of cemented carbide and ceramic tools, which endows it with an extremely long tool life when processing high-hardness materials.
Outstanding thermal stability: The heat resistance temperature of CBN is as high as 1400 to 1500℃, which is the highest among all tool materials, while diamond begins to oxidize or graphitize at 700 to 800℃. This makes CBN tools highly suitable for high-speed cutting and dry cutting.
Outstanding chemical stability: CBN does not undergo obvious chemical reactions with iron, nickel, cobalt and other iron group metals at 1200 to 1300℃, effectively avoiding the adhesion and diffusion wear of cutting tools. This is the key to its successful processing of steel materials.
Good thermal conductivity: The thermal conductivity of CBN is second only to that of diamond, which helps to quickly conduct the heat generated in the cutting zone, reduce the temperature of the tool tip, and protect the tool and workpiece.
Classification and Form
CBN cutting tools are mainly divided into two categories:
Integral polycrystalline cubic boron nitride (PCBN) cutting tools: The entire blade is made of CBN material without a center hole. It usually requires a dedicated tool holder and is suitable for intermittent cutting with large cutting depths and heavy loads.
Welded PCBN tools: CBN material is used as the cutting edge, welded onto a hard alloy substrate, with a center hole, and can be used interchangeably with standard tool holders. They are economical and suitable for both finish and semi-finish machining.
Cubic boron nitride (CBN) has become an indispensable super-hard tool material for processing high-hardness ferrous metals in modern manufacturing due to its high hardness, high thermal stability and chemical inertness to iron group metals. It not only realizes the technological innovation of "replacing grinding with turning", significantly enhancing production efficiency and processing accuracy, but also plays a key role in high-end manufacturing fields such as aerospace, automotive manufacturing, and national defense and military industry. With the acceleration of the localization process, Chinese enterprises are also occupying an increasingly important position in the CBN cutting tool market.