• Asian-Australasian Journal of Animal Sciences
• /
• v.23 no.1
• /
• pp.131-148
• /
• 2010

Piglet health at weaning is compromised due to several stress factors. Following the ban of antibiotic growth promoters new alternatives are required to control these problems. This paper reviews the evidence available for the use of spray dried animal plasma (SDAP) as an alternative to antibiotics in weaning pigs. Data from 75 trials in 43 publications involving over 12,000 piglets (mean values) have been used to calculate the performance responses of piglets according to several factors including SDAP origin, protein source from the control diet being replaced, dose of inclusion, age and weight of the piglets at weaning, sanitary conditions and simultaneous use or not of medication. Although the use of SDAP of all origins results in positive responses, it appears that plasma from porcine origin has the highest efficacy. This could be explained by the specificity of its IgG against porcine pathogens. During the first week post-weaning the response to plasma appears to increase with the inclusion dose, although over the two-week pre-starter period an optimal inclusion level of 4-8% is suggested. SDAP improves feed efficiency more markedly when the piglets are challenged with an experimental infection or when feed does not contain medication, which could be indicative of a lower expenditure of energy and nutrients to build an immune response against the challenge. There is evidence supporting that SDAP IgG and other bioactive substances therein prevent the binding of pathogens to the gut wall and reduce the incidence of diarrhoea in the post-weaning phase. Overall, plasma can be postulated as an excellent alternative to in-feed antimicrobials for piglets in the post-weaning phase.

• 연구논문집
• /
• s.25
• /
• pp.193-205
• /
• 1995

Plasma spray coating technology is essential for the microsemiconductor processes based on the electronic and computer industry, and extend gradually the range of application for up-to-date industry such as diesel engine and gas turbine components. These thechonoogies may be applied to the components requiring wear-resistance, heat resistance, fatigue-resistance, and corrosion-resistance. In this research, plasma spray technology was selected for the wear resistant coatings as the most proper technique. The final goal of this study is to improve the wear resistance through establishment of coating soft-ware, and basic research for industrialization of the technology concerned.

• Journal of Welding and Joining
• /
• v.18 no.5
• /
• pp.98-104
• /
• 2000

Aluminum alloys are being employed in automobile parts as strive to reduce overall vehicle weight to meet demands for improved fuel economy and reduction in vehicle emissions. Al-based composites reinforced with ceramic ($Al_2O_3,\;SiC,\;TiC\;and\;B_4C$) applications in a variety of components in automotive engines, such as liners, where the tribological properties of the material are important. In this study, Al-base composites reinforced with TiC particle powders has been developed for producing plasma spray coatings. The composite plasma spray powders were prepared Al-13Si-3Mg(wt%) alloy with TiC(40, 60 and 80wt%) particles ($0.2~5{\mu}textrm{m}$) by drum type ball milling. The composite powders ($36~76{\mu}textrm{m}$) were sprayed with plasma torch. Plasma sprayed coatings were heat-treated at $500^{\circ}C$ for 3 hours. The wear resistances of the plasma sprayed coatings were found to decrease with increasing TiC content and improved with heat treatment. AlSiMg-40% TiC heat-treated coatings were showed the best wear resistance in this study.

• Journal of the Korean Ceramic Society
• /
• v.52 no.6
• /
• pp.395-402
• /
• 2015

The suspension plasma spray (SPS) technique has been used to obtain dense $Y_2O_3$ coatings and to overcome the drawbacks of the conventional air plasma spray (APS). SPS uses suspensions containing micrometer or sub-micrometer sized powders dispersed in liquid media. In this study, microstructure developments and mechanical properties have been investigated as functions of particle size of source material and plasma processing parameters such as plasma power and stand-off distance. The microstructure of the coating was found to be highly related to the particle size and the plasma processing parameters, and it was directly reflected in the hardness and the adhesion strength. When fine powder (BET $16.4m^2/g$) was used as a raw material in the suspension, there was, with increasing stand-off distance, a change from a dense structure with a slightly bumpy surface to a porous structure with a cauliflower-like surface. On the other hand, when a coarse powder (BET $2.8m^2/g$) was used, the coating density was lower, with microscopic splats on the surface. Using fine $Y_2O_3$ powders, the coating layer with an optimum short stand-off distance showed a high hardness of approximately 90% of that of sintered $Y_2O_3$ and an adhesion strength several times higher than that of the coating by conventional APS.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.29 no.6
• /
• pp.359-364
• /
• 2019

The suspension plasma spraying is a modification of conventional plasma spray techniques that has been developed to overcome the challenge of using fine particles in plasma spray processes. In this study, microstructure developments and mechanical property of yttrium oxide (Y₂O₃) coatings prepared by the suspension plasma spray coating technique have been investigated to determine the effect of processing parameters including plasma gun current and total gas flow. The results showed that a highly dense Y₂O₃ coating having low porosity of 0.2 vol% without any lamellar structures can be achieved at the optimum condition of gun current 200 A and total gas flow 220 L/min.

• Korean Journal of Materials Research
• /
• v.31 no.3
• /
• pp.172-180
• /
• 2021

In this study, using the plasma spray method, tensile and compression fatigue tests are performed in saline solution to examine the effect of Ti undercoat on corrosion fatigue behavior of alumina-coated specimens. The alumina-coated material using Ti in the undercoat shows better corrosion fatigue strength than the base material in the entire stress amplitude range. Fatigue cracking of UT specimens occurs in the recess formed by grit-blasting treatment and progresses toward the base metal. Subsequently, the undercoat is destroyed at a stage where the deformation of the undercoat cannot follow the crack opening displacement. The residual stress of the UT specimen has a tensile residual stress up to about 100 ㎛ below the surface of the base material; however, when the depth exceeds 100 ㎛, the residual stress becomes a compressive residual stress. In addition, the inside of the spray coating film is compressive residual stress, which contributes to improving the fatigue strength characteristics. A hardened layer due to grit-blasting treatment is formed near the surface of the UT specimen, contributing to the improvement of the fatigue strength characteristics. Since the natural potential of Ti spray coating film is slightly higher than that of the base material, it exhibits excellent corrosion resistance; however, when physiological saline intrudes, a galvanic battery is formed and the base material corrodes preferentially.

• Transactions of the Korean hydrogen and new energy society
• /
• v.21 no.3
• /
• pp.201-206
• /
• 2010

In present work, $La_{0.8}Ca_{0.2}CrO_3$ (LCC) ceramic interconnect layer for SOFC was prepared by using thermal plasma spray coating process. The LCC powders were synthesized by Pechini method and calcined at the temperature of $1000^{\circ}C$. The prepared LCC powder was characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM), particle counter, BET analysis, respectively. In addition, basic and essential properties of LCC layer coated by thermal plasma spray coating process such as the morphology of surface and cross section for coated layer, gas leak rate, and electrical conductivity were analyzed and discussed. Based on these experimental results, it can be concluded that the LCC layer coated by thermal plasma spray coating process can be suitable as a ceramic interconnect of SOFC operated at $800^{\circ}C$.

• Proceedings of the KWS Conference
• /
• 1999.10a
• /
• pp.124-127
• /
• 1999

• Tribology and Lubricants
• /
• v.22 no.5
• /
• pp.282-289
• /
• 2006

This paper is to investigate the wear behaviors of two type ceramics, $Al_{2}O_{3}\;and\;TiO_{2}$, by coated plasma thermal spray method under the lubricative environment. The lubricative environments are grease fluids, a general hydraulic fluids, and bearing fluids. The wear testing machine used a pin on disk type. Wear characteristics, which were friction force, friction coefficient and the specific wear rate, according to the lubricative environments were obtained at the four kinds of load and sliding velocity is 0.2 m/sec. After the wear experiments, the wear surfaces of the each test specimen were observed by a scanning electronic microscope.

• Proceedings of the Korean Powder Metallurgy Institute Conference
• /
• 2006.09a
• /
• pp.53-54
• /
• 2006

Ti-Zr-Ni coatings deposited by low vacuum plasma spray technique consisted of nanometer-sized $W-Ti_{50}Zr_{35}Ni_{15}$ 1/1 cubic approximant and TiZrNi Laves phases as well as a low volume fraction of $ZrO_2$ phase. The shift of composition during deposition of the quasicrystalline powders and the presence of $ZrO_2$ phases are believed to be responsible for the reduced corrosion performances evaluated by means of electrochemical tests in a Hanks' Balance Salt Solution at $37^{\circ}C$.