OPC 기반의 지능형 정밀 서보제어 분말성형 프레스 시스템의 설계 및 구현

유남현 한국전자통신학회 2018 한국전자통신학회 논문지 Vol.13 No.6

Metal Powder Metallurgy is a manufacturing technology that makes unique model parts or a certain type of product by using a hardening phenomenon when a powder of metal or metal oxide is put into a mold and compression-molded by a press and then heated and sintered at a high temperature. Powder metallurgical press equipment is mainly used to make parts of automobile, electronic parts and so on, and most of them are manufactured using precise servo motor. The intelligent precision servo control powder molding press system designed and implemented in this paper has advantages of lowering the price and maintaining the precision by using the mechanical camshaft for the upper ram part and precisely controlling the lower ram part using the high precision servo system. In addition, OPC-based monitoring and process data collection systems are designed and implemented to provide scalability that can be applied to smart manufacturing management systems that utilize Big Data in the future. 금속분말 야금은 금속이나 금속산화물의 분말을 금형에 넣어 프레스로 압축 성형한 후에 고온으로 가열 소결하면 굳어지는 현상을 이용하여 독특한 모형의 부품이나 일정한 형태의 제품을 만드는 제조 기술이다. 분말야금 프레스 장비는 자동차, 전자 부품 등의 핵심 정말 부품을 만드는데 사용되기 때문에 이를 위하여 정밀한 서보 모터를 사용하여 제작되는 경우가 대부분이다. 본 논문에서 설계 및 구현한 지능형 정밀 서보제어 분말성형 프레스 시스템은 상부 램 부분은 기계식 캠축을 사용하고 하부 램 부분은 고정밀 서보 시스템을 활용하여 정밀하게 제어함으로써 가격대를 낮추면서도 정밀도를 유지할 수 있는 장점을 가진다. 또한 OPC 기반의 모니터링 및 공정 데이터 수집 시스템을 설계 및 구현함으로써 향후 빅 데이터를 활용한 스마트 제조 관리 시스템에 적용될 수 있는 확장성을 제공한다.

급속 응고 분말 야금으로 제조된 알루미늄 합금의 용접성에 대한 연구

고진현 한국기술교육대학교 1997 論文集 Vol.4 No.1

The weldability of aluminum alloys made by the rapid solidification powder metallurgy was investigated by the hot cracking susceptibility test and microstructural examination. In this study, the optimum welding conditions for gas metal arc welding and electron beam welding processes were also established to weld aluminum alloys made by powder metallurgy. The weld beads of aluminum alloys insufficiently degassed showed nonuniform shape of beads, undercut and porosity in the weldments, while those of fully degassed aluminum alloys showed uniform beads and little porosity in the weldment. Based on this study, it can be recommended that the hot cracking susceptibility of aluminum alloys made by powder metallurgy can be minimized by controlling the homogenization temperature and the degree of recrystallization, which produce the fine-grained microstructure.

항공기 터빈 디스크용 니켈기 초내열 분말야금 합금의 고온 피로균열진전 거동 비교 평가

윤동현(Dong Hyun Yoon),나성현(Seong Hyeon Na),김재훈(Jae Hoon Kim),김홍규(Hongkyu Kim),김동훈(Donghoon Kim) 대한기계학회 2017 大韓機械學會論文集A Vol.41 No.8

항공기 터빈 디스크에 사용될 수 있는 니켈기 초내열 분말야금 합금의 피로균열진전 거동이 실제운전 환경을 고려하여 상온 및 650℃에서 연구되었다. ASTM E647에서 제시하는 직류전위차법을 이용하여 실시간으로 균열의 진전을 측정하였다. 또한 피로균열진전 시험은 응력비 0.1과 0.5의 두가지 조건에서 수행되었다. 시험결과들은 응력비와 온도 조건 모두 피로균열진전 거동에 영향이 있음을 보여주었으며, 응력비와 온도가 증가함에 따라, 니켈기 초내열 분말 야금 합금의 피로균열성장 속도는 증가하게 관찰되었다. 본 연구에서 사용된 니켈기 초내열 분말 야금 합금은 현재 개발 중인 소재로써 보다 정량적인 시험결과의 분석을 위해, 본 연구의 피로균열진전 시험결과와 기존에 연구된 Inconel-100 소재의 피로균열진전거동에 대한 상호 비교분석이 수행되었다. 피로균열진전 파단면의 분석은 SEM 촬영을 통하여 수행하였다. The behavior of fatigue crack growth of nickel-based powder metallurgy superalloy that could be used in aircraft turbine disc is investigated at room temperature, and 650℃ considering real operating conditions. The direct current potential drop(DCPD) method was used to measure the crack length of material in real time according to ASTM E647. Tests were performed with various stress ratios (0.1 and 0.5). Experimental results show that stress ratio, and temperature all affect the behavior of fatigue crack growth. As the stress ratio and temperature increase, the fatigue crack growth rate of nickel-based powder metallurgy superalloy also increases. Results were compared and reviewed with fatigue crack growth rates of other nickel-based superalloy materials (Inconel-100) that were studied in previous papers. Fractography analysis of the fractured specimens was performed using as SEM.

DCPD법을 이용한 분말야금 니켈기 초내열합금의 고온 피로균열진전거동

나성현(Seonghyeon Na),오광근(Kwangkeun Oh),김홍규(Hongkyu Kim),김동훈(Donghoon Kim),김재훈(Jaehoon Kim) 한국추진공학회 2016 한국추진공학회지 Vol.20 No.2

Powder metallurgy nickel based superalloy has been used in a high temperature part of turbine engine for airplane. The fatigue crack growth behavior was investigated using CT specimens for the materials at room temperature(R.T.), 600℃ and 700℃. The direct current potential drop(DCPD) method suggested by ASTM E647 was used to measure the crack length during fatigue crack growth at various stress ratios. The fatigue crack growth rate at R=0.5 was faster than that at R=0.1 for all temperature conditions and increased with the increase of stress ratio and temperature. Fractography was conducted for analysis of fracture mechanism.

분말야금공정으로 제조된 TiC/steel 금속복합재료의 미세조직 및 기계적 물성 연구

이지혜 ( Jihye Lee ),조승찬 ( Seungchan Cho ),권한상 ( Hansang Kwon ),이상관 ( Sang-kwan Lee ),이상복 ( Sang-bok Lee ),김대하 ( Daeha Kim ),김정환 ( Junghwan Kim ) 한국복합재료학회 2021 Composites research Vol.34 No.5

본 연구에서는 3 wt.%, 10 wt.% Cr이 함유된 Fe-합금 분말을 기지 금속으로 하여 분말야금공정을 통해 TiC/steel 금속복합재료를 제조하였다. 이후 복합재료의 기계적 물성에 미치는 열처리의 영향을 고찰하고자, 어닐링 열처리 및 칭-템퍼링 열처리를 실시하였다. 인장, 압축 그리고 항절력 시험과 미세조직 분석을 통하여 Cr 함량 및 열처리 조건에 따른 미세조직의 변화와 구조적 강도 변화의 연관성을 고찰하였다. 10 wt.% Cr을 함유한 TiC/steel의 경우, TiC/steel 계면에서 형성된 조대한 Cr carbide의 영향으로 상온 인장강도 및 항절력이 크게 저하하였다. 이에 반해 압축강도에서는 Cr이 3 wt.%, 10 wt.% 함유된 TiC/steel 복합재료 모두 Cr carbide의 유무와 관계없이 어닐링 열처리 시편에 비해 칭-템퍼링 열처리 후 약 4 GPa에 달하는 높은 압축강도를 보였다. In this study, TiC/steel metal matrix composites were fabricated by powder metallurgy process using Fealloy powders with 3 wt.% Cr and 10 wt.% Cr, respectively, as matrix material. Subsequently, the composite samples were heat treated by the annealing and quenching-tempering(Q-T), respectively, to understand the effect of heat treatment on the mechanical properties of the composites. The correlation between microstructure and structural strength depending on the chromium content and the heat treatment conditions was studied through tensile, compressive, and transverse rupture test and microstructural analysis. In the case of TiC/steel composite containing 10 wt.% Cr, the tensile strength and transverse rupture strength at room temperature were significantly lowered by the influence of coarse chromium carbide formed at the TiC/steel interface. On the other hand, both TiC/steel composites containing 3 wt.% Cr and 10 wt.% Cr showed much higher compressive strength of about 4 GP after quenchingtempering compared to the annealed specimens regardless of the presence of the chromium carbide.

분말 야금에 의해 소결된 강철의 트라이볼로지 특성 향상

최세이미,카림바예프 루슬란,편영식,AMANOVAUEZHAN 한국트라이볼로지학회 2020 한국트라이볼로지학회지 (Tribol. Lubr.) Vol.36 No.4

Materials manufactured by powder metallurgy (PM) are widely used in various applications such as water pump, shock absorber, and airplane components due to the reduction in the cost and weight. In this study, tribological properties of carbon steel subjected by surface treatment were investigated. The main purpose is to increase the strength and improve the tribological properties by reducing pores that formed by PM. Moreover, the surface treatment was carried out at room and high temperatures (RT and HT). The surface roughness of the untreated (NON) and treated (AFTER) samples was measured. It was found that the surface roughness was reduced after both the RT AFTER and HT AFTER compared to RT NON sample. The tribological properties of the samples were performed against bearing steel ball under dry conditions. The friction coefficient of the RT NON samples was reduced by 22% and 56% RT AFTER and HT AFTER, respectively. The wear volume of the RT NON sample was also reduced by 43% and 87% RT AFTER and HT AFTER, respectively. Tribocorrosion tests were also performed and it was found that the surface of the RT AFTER, HT AFTER samples was less corroded compared to RT NON sample. The HT AFTER sample demonstrated a relatively higher corrosion potential in comparison with the RT AFTER samples. Hence, it was confirmed that after surface modification the surface roughness and hardness of the samples were significantly improved resulting in improvement in tribological and tribocorrosion behaviors of PM carbon steel.

직류전위차법을 이용한 분말야금 니켈기 초내열합금의 피로균열진전거동 평가

나성현(Seonghyeon Na),오광근(Kwangkeun Oh),김재훈(Jaehoon Kim) 한국추진공학회 2015 한국추진공학회 학술대회논문집 Vol.2015 No.11

분말야금 니켈기 초내열합금은 항공기 터빈 엔진의 고온용 부품으로 사용된다. 본 연구에서는 분말야금 니켈기 초내열합금의 피로균열진전 시험은 상온과 600 ℃의 온도 조건에서 수행되었다. 피로균열 진전속도에 대한 평가방법은 ASTM E647에서 제시한 직류전위차법을 이용하여 산출하였다. 이러한 결과로부터, 분말야금 니켈기 초내열합금의 피로균열 진전 속도는 응력비 0.5 일 때 더 높고, 균열은 응력비 0.1 일 때 낮은 응력확대계수부터 시작한다. 파단면 관찰은 주사전자현미경을 이용하여 분석하였다. Powder metallurgy Nickel based superalloy is used to manufacture high temperature parts of turbine engine for airplane. In this study, fatigue crack growth tests for the material are conducted by temperature conditions at room temperature and 600 ℃. Evaluation method for fatigue crack growth rate calculated using DCPD method suggested by ASTM E647. From these results, fatigue crack growth rate of the material is higher when stress ratio is 0.5. When stress ratio is 0.1, crack begins from lower stress intensity factor. Fractography was carried out by Scanning Electron Microscope(SEM).

유한요소해석을 이용한 오일리스 베어링의 분말 압축 성형에 관한 시뮬레이션

박민혁(Min-Hyeok Park),강한빈(Han-Bin Kang),송주한(Ju-Han Song),백인석(In-Seok Pack),이동욱(Dong-Ug Lee),김덕주(Duk-joo Kim),이석순(Seok-Soon Lee) 한국기계가공학회 2013 한국기계가공학회지 Vol.12 No.2

In this study, simulation on the powder compression forming of oilless bearing is performed and the analysis results are compared with the actual products. This study aims to examine the suitability of powder compression for bearing by using FEA(finite element analysis) before full-scale production. The lubrication state can be predicted by changing the coefficient of friction in order to get the optimal density gradient. Analysis for single and double action presses are performed and these results are compared with each other. State and process of optimal lubrication are proposed from the study result.

분말야금으로 제작된 M2 공구강과 Cu 간 기능성 경사 복합재의 물성 평가

정종설(Jong-Seol Jeong),신기훈(Ki-Hoon Shin) 대한기계학회 2014 大韓機械學會論文集A Vol.38 No.9

형상적응형 냉각회로를 구비한 사출금형 및 히트 싱크를 가지는 절삭공구 (혹은 냉각 장치) 등과 같은 많은 응용 분야에서 기능성 경사 복합재(FGM)를 사용하여 필요한 강성을 약화시키지 않으면서 열전도 특성을 향상 시킬 수 있을 것으로 기대된다. 본 논문에서는 M2 공구강과 Cu 간의 FGM 히트 싱크를 가지는 절삭 공구 제작을 위한 기초연구로, M2 와 Cu 를 각각 100:0, 80:20, 60:40, 40:60, 20:80, 0:100 wt% 비율로 사전에 혼합한 금속분말을 분말야금법으로 가압성형 및 소결 제작 하였다. 각 시편의 단면을 광학현미경으로 관찰하여 소결 상태를 분석하였으며, 열전도도, 비열 및 열팽창계수 등 열전달 관련 물성을 측정하고 분석하였다. The use of functionally graded materials (FGMs) may enhance thermal conductivity without reducing the desired strength in many applications such as injection molds embedding conformal cooling channels and cutting tools with heat sinks (or cooling devices). As a fundamental study for cutting tools having FGM heat sinks between M2 tool steel and Cu, six FGM specimens (M2 and Cu powders were premixed such that the relative compositions of M2 and Cu were 100:0, 80:20, 60:40, 40:60, 20:80, and 0:100 wt%) were fabricated by powder metallurgy in this study. The cross sections of these specimens were observed by optical microscopy, and then the material properties (such as thermal conductivity, specific heat, and coefficient of thermal expansion) related to heat transfer were measured and analyzed.

3차원 분말야금 공정 시뮬레이터-PMsolver 3D

이민철(Min-cheol Lee),정석환(Suk-hwan Chung),권영삼(Young-sam Kwon),조주현(Ju-hyun Cho),전만수(Man-soo Joun) 대한기계학회 2007 대한기계학회 춘추학술대회 Vol.2007 No.11

We developed a three-dimensional power metallurgy process simulator for die compaction and sintering analyses, called PMsolver3D. The simulator is based on the continuum models for die compaction and sintering process. The theories were given in detail with emphasis on the constitutive models. We adopted the tetrahedral mesh system to increase the applicability and automate the simulation including remeshing. Of course, we have the optional capability of hexahedral elements. Typical simulation examples of only die compaction analysis, only sintering analysis and the coupled analysis of die compaction and sintering were given, which shows the applicability and versatility of the developed program PMsolver3D.