• 한국결정성장학회지
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• 제27권2호
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• pp.70-74
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• 2017

건식 진동밀과 습식 볼밀로 출발원료를 혼합/분쇄하여 나트륨이온전지용 양극활물질인 $Na_{2/3}(Ni_{1/3}Mn_{2/3})O_2$를 합성하여 특성을 비교하였다. 건식 진동밀로 혼합/분쇄한 분말은 습식 볼밀한 분말보다 더 미세한 $1{\mu}m$ 이하의 입자였으며, $875{\sim}900^{\circ}C$에서 열처리 하였을 때 단일상을 얻을 수 있었다. 또한 전지 특성도 건식 진동밀을 사용한 분말이 습식 공정으로 합성한 분말보다 방전용량이 크고 방전 전위도 높게 나왔다.

• Advances in materials Research
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• 제9권3호
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• pp.189-202
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• 2020

The objective of the present work is to investigate the effect of cutting parameters (Vc, fz and ap) on tool life and the level of vibrations velocity in the machined part during face milling operation of hardened AISI 52100 steel. Dry-face milling has been achieved in the annealed (28 HRc) and quenched (55 HRc) conditions using multi-layer coating micro-grain carbide inserts. Statistical analysis based on the Response surface methodology (RSM) and ANOVA analysis have been conducted through a plan of experiments methodology using a reduced Taguchi table (L9) in order to obtain engineering models for tool life and vibration velocity in the workpiece for both heat treatment conditions. The results show that the cutting speed has a dominant influence on tool life for both soft and hard part. Cutting speed and feed per tooth is the most significant parameters for vibration levels. Comparing the experimental values with those predicted by the developed engineering models of tool life and levels of vibrations velocity, a good correlation has been obtained (between 97% and 99%) in annealed and hard conditions.

• 대한기계학회논문집A
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• 제24권10호
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• pp.2496-2501
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• 2000

High speed ball end milling is attracting interest in the aerospace industry for the machining of complex 31) airfoil surfaces in nickel based superalloys, Experimental work is detailed on the effect of cutter orientation on tool life, cutting forces, chip formation, specific force and workpiece surface roughness, when high speed ball end milling nickel based supperalloy(lnconel 718). Dry cutting was performed using 8min diameter solid carbide cutters coated with either TiA1N or CrN for the workpiece mounted at an angle of 45˚ from the cutter axis. A horizontal downwards cutting orientation provided the best tool life with cut lengths~50% longer than for all other directions. Evaluation of cutting forces and associated spectrum analysis of results indicated that cutters employed in a horizontal downwards direction produced the least vibration.