At  the beginning of 2018, the Key Laboratory of Materials Electromagnetic  Process Research of the Northeastern University began to provide  titanium alloy processing tool coating for Hitachi Metals Co., Ltd. This  is the first time that Northeastern University has processed titanium  alloy high-speed cutting tools for foreign companies. It has not only  broken the technical blockade of Chinese titanium alloy high-speed  cutting tools, but also successfully achieved counter-attacks, marking  that China's titanium alloy high-speed cutting tools have reached  international standards. Leading level.

Titanium  is an important structural metal widely used in the manufacture of  high-end equipment such as aerospace, marine engineering and medical  equipment. Titanium  alloy is not only difficult to prepare, but also difficult to cut in  the manufacturing process of the product, which has become one of the  bottlenecks restricting the development of China's high-end equipment  manufacturing industry.

When  the hardness of titanium alloy is greater than HB350, it is difficult  to cut. When it is less than HB300, it is prone to sticking and it is  difficult to cut. In  the actual production process, in order to prevent the cutting  temperature from being too high, most of the titanium alloy processing  enterprises in China adopt the traditional processing method of “low  speed, large depth of cut and small feed”, and the tool wears quickly. Foreign  high-quality knives have restricted exports to China. The cruel reality  has made China's titanium alloy cutting speed and processing efficiency  far behind those of developed countries such as Europe and America.

The  development of new tools for efficient cutting of titanium alloys has  become a common concern in the field of high-end equipment manufacturing  and metal cutting research. In  2012, Wang Qiang, a key laboratory of the Ministry of Education for  Materials Electromagnetic Process Research of Northeastern University,  led the “High-speed Cutting Process and Tool Materials Research for  Aerospace High-strength Lightweight Materials Typical Parts” project and  won the “High-end CNC Machine Tool and Basic Manufacturing Equipment”. Funded for major science and technology projects.

The  research team, based on the major national science and technology major  projects, and the Institute of Metal Research of the Chinese Academy of  Sciences, jointly carried out high-speed cutting technology for  aerospace and titanium alloy materials and high-performance tool  materials. In  view of the difficult-to-cut properties of titanium alloys such as "low  thermal conductivity, low modulus of elasticity, and high chemical  reactivity", the research team focused on teamwork and studied these  problems one by one.

After  three years of numerous experiments, the research team successfully  developed a new type of high-speed cutting tool for titanium alloy with  international leading level. The  tool adopts ultra-fine grain gradient cemented carbide tool material  with surface grain size of less than 0.6μm and functional composite  nano-tool coating technology, which successfully overcomes the problems  of high cutting temperature and low cutting efficiency when the reaction  activity is high. It  effectively solves the problems of chipping and the like caused by easy  bonding between the tool and the titanium alloy, and lays a solid  foundation for the development of China's high-end equipment  manufacturing industry.

In  2014, the overall ultra-fine grained carbide milling cutter, ultra-fine  grained carbide milling insert and surface-modified carbide milling  insert developed by the research group were carried out in the center of  titanium alloy in a certain aircraft industry (Group) Co., Ltd. Machining of the wing butt strap. Among  them, the overall ultra-fine grained carbide milling cutter achieves  stable cutting at a cutting speed of 160 m/min, and the processing  efficiency is improved by 42.2%. The  practical application shows that the coated milling insert developed by  Northeastern University achieves stable high-speed machining of  titanium alloy parts.

In  2015, the ultra-fine grain gradient functional carbide inserts  developed by the research group were tested by the National Tool Quality  Supervision and Inspection Center. Under the conditions of finishing  titanium alloy at a cutting speed of 100m/min, the cutting performance  exceeded that of similar tools at home and abroad. The  processing efficiency is increased by more than 50%. Under the  condition of rough machining of titanium alloy at a cutting speed of  60m/min, the cutting performance is comparable to that of similar tools  at home and abroad, and the processing efficiency is increased by more  than 50%. The  test of the National Tool Quality Supervision and Inspection Center  shows that the tool performance developed by Northeastern University  exceeds the level of similar products at home and abroad. The overall  technology has reached the international advanced level, and some of the  cutting tool products are internationally leading, breaking the  long-term technological monopoly of foreign companies.

With  the continuous development and improvement of new tools for high-speed  cutting of titanium alloys, the tools and technology developed by the  research team have won the favor of many companies. The  surface-modified cemented carbide tool has been verified by the rough  machining of titanium alloy by Shenzhen Haizhou CNC Machinery Tool Co.,  Ltd., and the wear rate is reduced by 64% at a cutting speed of 70m/min,  which truly achieves the effect of cutting "titanium". , has won wide acclaim from tool manufacturers and users.

In  the specific and production practice, the research group has gradually  established a high-speed cutting process specification for typical  titanium alloy parts, significantly improving the cutting speed and  processing quality, and effectively reducing the processing cost. At  present, Shenyang City and Shitai General Titanium Industry Co., Ltd.  and Japan's Hitachi Metals have expressed strong interest in the new  high-speed cutting tools for titanium alloys in Northeastern University,  and hope to further strengthen cooperation.

Wang  Qiang said that a high-end equipment manufacturing industrial park  between China and Germany (Shenyang) signed a strategic cooperation  agreement with Northeastern University, and the high-speed cutting  coating tool project landed in Sino-German Park. The  new high-speed cutting tool for titanium alloy, which is about to enter  the mass production stage, will greatly promote the development of  high-end manufacturing enterprises such as airplanes and automobiles,  and create huge economic and social benefits.