จำนวน Repository ( 4 )
การพัฒนาผลิตภัณฑ์เครื่องมือตัดปาดผิวโลหะนาโนเมตรจากโลหะผงทังสเตนคาร์ไบด์ที่ผลิตภายในประเทศ
The tungsten carbide powder which recycled from the scarps of cemented tungsten carbide produces the purity of 99%. Using this tungsten carbide powder to manufacture a cutting tool and test its properties are the main objective of this work. Based on the standard SNMG 120408 the cutting tool with the dimension of 12.7x12.7x4.76 is fabricated. With the 100 hours of Ball milling grinding Cobalt mixing and sintering at 1430 °C the experimental result is impressive. At 15% of mixedcobalt the cutting tool with the hardness of 2031.6 HV be able to cut S45C steel in the feed rate of 0.2 meters per revolution and 45 m/min in the cutting speed. Besides that it provides the depth of cut of 0.25 mm and when it reaches the cutting distance of 4200 mm the surface roughness is 3.65 μm. In comparison with the cutting tool made of imported tungsten carbide powder which has a hardness of 1254 HV it turned out that our cutting tool has the equivalent quality in terms of hardness and wear resistance. Hence this work is considered to be a material development and a tungsten carbide cutting tool manufacture those would be the vital base to lead us to a commercial production.
การพัฒนาโครงสร้างเกรนต้านทานการสึกหรอของชิ้นงานความแข็งสูงพิเศษด้วยกระบวนการอบผนึก
This study developed the cemented tungsten carbide by steadily sintering at 1430 °C for one hour. The tungsten carbide structure is a long shape. Its grain size has a difference between width and length and there are high distribution of sizes and shapes. In comparison with the work piece which has the similar size of grain structure the milling duration of tungsten carbide is less even though the condition of WC-Co is the same (95% WC – 5% Co). When the sintering of 1400 °C with the identical milling duration is performed. It turned out that both grain structures of the tungsten carbide and the work piece are similar and their grain sizes are slightly different. However when the grain structures are almost the same and sphericity is increased the hardness and wear resistance will also be improved. Therefore the size of grain structure between 1.00 – 3.00 μm with the milling duration of 100 hours will provide a work piece that has a wear resistance according to international standard
การพัฒนากระบวนการอบผนึกชิ้นงานความแข็งสูงพิเศษเพื่อเพิ่มประสิทธิภาพ การต้านทานการสึกหรอตามแนวทางการจัดการวัสดุเพื่อความยั่งยืน
This study aims to development of production process of hard metal by tungsten carbide powder with the particle sized of 0.1 - 0.35 µm. This carbide powder were made of recycling cemented carbide tool scraps so it is mixed with Ta = 2.82 % Mo = 0.45 % Nb = 1.22 % Ti = 4.56 % Zr = 0.37 % The shape of the carbide powder are roughly round due to ball milling for 300 hours. It was mixing cobalt 10 % and Paraffin wax 2 % which is found the work piece that running through the process of sintering with a temperature of 1400 °c and 1430 °c have the hardness of 1368.5 and 1346.3 HV respectively. In one hour of holding time process the work piece with 1430 °c of the sintering causes less wear. After the test of turning operation it can be concluded that the tungsten carbide cutting tool provides the equivalent quality as a standard cutting tool.
พัฒนาโลหะมีค่าชนิดทังสเตนคาร์ไบต์ผ่านการรีไซเคิลหมุนเวียนมาใช้ใหม่เพื่อผลิตชิ้นส่วนโลหะความแข็งสูง
This research was on the production of hardmetal from recovery of tungsten carbide tool scraps recycling through ball milling for 40 hours. The metal powder obtained which was of the size between 0.11-0.22 µm was composed of 96.69% of tungsten carbide (WC) 1.68% of tantalum (Ta) 1.21% of titanium (Ti) and 0.42% of niobium (Nb). When mixed with 5-15% cobalt binder metal cold isostatic press (CIP) sintered at 1450 ° C it became hardmetal work piece dimension 12.39 x 13.82 x 5.60 mm with 1410 HV hardness and 14.34 g/cm3 density. The result of S45C steel turning was tools life good. The research concluded that the hardmetal work piece produced by the developed material had suitable basic specification and would lead to the development in working in the future.