Characteristics of complicated AISI316L automobile components manufactured by powder/metallurgy

L. Zhong Liang,L. Jin Hui,S. Yu Sheng,Y. Chun Ze 대한기계학회 2009 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.23 No.7

Indirect Selective Laser Sintering/ Isostatic Pressing (SLS/IP), with Cold Isostatic Pressing (CIPing) and Hot Isostatic Pressing (HIPing) IPs, is adopted for the manufacture of complicated automobile components. The preparation of PA12-coated AISI316L powder and airproof plastic canning during CIPing are also investigated. The influence of technology parameters on the performances of AISI316L specimens during SLS/IP is likewise analyzed. Results show that PA12-coated AISI316L powders are successfully prepared through the dissolution and precipitation process, and that it is better to fabricate airproof canning for complicated components with natural latex. After sintering AISI316L specimens from 1300℃ to 1340℃ (CIPed at more than 300 MPa ahead), their relative densities increased, approaching 92%. Subsequently, their relative densities are improved by HIPing, whose optimal pressure and temperature parameters are between 90 MPa and 20 MPa, and 1150℃ and 1250℃, respectively. The optimal tensile performances are close to those of annealed AISI316L compact materials.

Effects of Supplementing with Single or Multiple Trace Minerals on Growth Performance, Fecal Mineral Excretion and Nutrient Utilization in Pullets from 1 to 18 Weeks of Age

Zhong, L.L.,Yao, J.H.,Cheng, N.,Sun, Y.J.,Liu, Y.R.,Wang, Y.J.,Sun, X.Q.,Xi, H.B. Asian Australasian Association of Animal Productio 2007 Animal Bioscience Vol.20 No.6

This study investigated whether supplemental Cu, Fe, Zn, and Mn are needed in a practical diet for pullets. Four hundred and twenty females of an egg-laying strain (1-d-old, Lohmann Brown Layer) were randomly distributed into 4 groups, consisting of 7 replicates of 15 birds each. During the 18-week experimental period, chicks were given three basal diets in sequence, each with single or multiple Mn, Zn and Cu supplementation to improve the mineral balance gradually. In the Control, no Mn, Zn, and Cu were added; in the single Mn supplemented group (sMn) Mn was added to 120, 60, and 60 mg/kg for 1-6, 7-12, and 13-18 weeks of age, respectively; in the multiple Mn and Zn supplemented group (mMnZn), Mn was added to 180, 90, and 90 mg/kg and Zn was added to 120, 105, and 105 mg/kg for 1-6, 7-12, and 13-18 weeks of age, respectively; in the multiple Mn, Zn, Cu supplemented group (mMnZnCu), Mn, Zn, and Cu were added to the same multiple of basal Fe concentration relative to NRC (1994) recommendations. Energy and protein metabolizability were determined by subtracting energy/protein intake by energy/protein excretion (from both feces and urine) and dividing by energy/protein intake. There were no statistically significant differences between groups in terms of feed intake, final body weight or tibia length throughout the experiment. Optimal growth performance was observed in the Control, while adding trace minerals to basal diets tended to result in decreased productive performance. Protein metabolizability was increased by mMnZn and mMnZnCu treatments, but energy metabolizability was not affected. Concentrations of Mn, Zn, Cu in excreta varied greatly related to dietary content, and the retentions of Cu, Fe, Zn and Mn were all increased due to the improvement of mineral balance. Based on these results, it is suggested that the concentrations of Cu, Fe, Zn and Mn in typical basal diets used in this study were adequate for normal growth for pullets from 1 to 18 weeks of age.

DETERMINATION OF THE APPARENT ILEAL DIGESTIBILITY OF PROTEIN AND AMINO ACIDS IN FEEDSTUFFS AND MIXED DIETS FOR GROWIG-FINSHING PIGS WITH THE MOBILE NYLON BAG TECHNIQUE

Yin, Y.L.,Zhong, H.Y.,Huang, R.L. Asian Australasian Association of Animal Productio 1995 Animal Bioscience Vol.8 No.5

A series of experiments was conducted to determine the influence of various pepsin-HCL pretreatment factor, hereby the factors of duration of washing for the retrieved bags, inherent to the mobile nylon bag technique (MNBT), on apparent ileal digestibility of crude protein (AIDCP) and apparent ileal digestibility of dry matter (AIDDM). At last, the AIDCP and apparent ileal digestibility of amino acids (AIDAA) in maize, barley, wheat, rapeseed meal, cottonseed meal and three mixed diets were determined with the MNBT and ileo-rectal anastomis pigs (IRAT). For the MNBT techniques, bag measuring $25{\times}40$ MM and containing 0.75 g feedstuff samples, after pre-digestion in vitro, were introduced into the ileo-rectal anastomis pigs (IRAT) gastrointestinal tract through a duodenal cannula and recovered in the ileal digesta between 6 and 12 h. later. 1. The apparent ileal digestibility of dry matter (AIDDM) and crude protein (AIDCP) of the tested samples, with the exception of fish meal, determined by MNBT were not affected by the different pepsin-HCL pretreatment times in vitro between 2.5 h. and 4 h. 2. There was no significant (p > 0.05) difference of the AIDCP and AIDDM of maize determined by the MNBT among different pepsin concentration (0.03%, 0.07% and 0.1 %) treatment in vitro. 3. The AIDCP determined with the MNBT was affected by the washed and unwashed recovered bags from the ileal digesta. 4. The AIDCP and AID amino acids (AIDAA) of maize, barley, wheat, rapeseed meal, soya-bean meal, cottonseed meal and three mixed diets from the MNBT, with a solution of 0.01N HCL (PH 2) and 0.1% of pepsin concentration, a pepsin-HCL pretreatment time in vitro or 4h. and a washing time of the recovered bag from the ileal digesta compared well with those from the IRAT. The linear regression analysis showed a significant correlation (p < 0.01) of AIDCP and AIDDA between the IRAT and MNBT.

Formulation and evaluation of incompatible but convergent rational quadrilateral membrane elements

Batoz, J.L.,Hammadi, F.,Zheng, C.,Zhong, W. Techno-Press 2000 Structural Engineering and Mechanics, An Int'l Jou Vol.9 No.2

This paper presents four incompatible but convergent Rational quadrilateral elements, two four-node elements (RQ4Z and RQ4B) and two five-node elements (RQ5Z and RQ5B). The difference between the so-called Rational Finite Element (Zhong and Zeng 1996) and the Free Formulation (Bergan and Nygard 1984) are discussed and compared. The importance of the mode completeness in these formulations is emphasized. Numerical results for several benchmark problems show the good performance of these elements. The two five-nodes elements RQ5Z and RQ5B, which can be viewed as complete quadratic mode elements (with seven stress modes), always give better results than the four nodes elements RQ4Z and RQ4B.

Growth Performance, Carcass Composition and Meat Quality of Jiulong-yak (Bos grunniens)

Zi, X.D.,Zhong, G.H.,Wen, Y.L.,Zhong, J.C.,Liu, C.L.,Ni, Y.A.,Yezi, Y.H.,Ashi, M.G. Asian Australasian Association of Animal Productio 2004 Animal Bioscience Vol.17 No.3

Estimated liveweights, carcass characteristics, the proximate composition and amino-acid composition of the whole rib cut of the 10th/12th thoracic vertebrae have been determined for Jiulong-yak. The animal grows rapidly up to puberty at 2-3 years of age. At those ages, females reached 143.0$\pm$34.7 kg and 184.0$\pm$30.8 kg (SD) respectively, which was 60 to 80% of their mature weight at 6 to 7 yr old, then the rate of growth significantly slowed down. Males continued to rapidly increase body weight until an older age possibly due to the selection procedures. Animals included 20 males aged from 2.5 to 6.5 yr, seven females aged of 4.5 yr and 11 steers aged of 4.5-5.5 yr were slaughtered for carcass determination and chemical analysis of meat samples. Dressing-out percentage and ribeye area ranged from 48.53-55.04% and 48.02-68.56 $cm^2$ respectively, both of which differed by age and sex. Yak meat is scarlet in color and intramuscular marbling is poor. The 10th/12th rib-cut contained 24.99-31.93% dry matter; 19.98-22.58% protein; 2.52-10.86% fat and 0.93-1.00% ash. Meat from females and steers contained a higher percentage of fat than those from bulls. The pH of M. Longissimus dorsi measured at 24 h post-mortem ranged from 5.84-6.11. Amino acid composition was similar to that for other red meat, except for a lower content of methionine (1.26 g/100 g meat). The results indicated that yak meat can make a valuable contribution to the diets for the highlanders.

Research on air diversion channel of air-cooled gasoline engine cylinder head and simulation of fluid- solid coupling heat transfer

Du B. C.,Tang G. Z.,Zhang L.,Zhong L.,Deng T.,Yi Y. L. 대한기계학회 2017 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.31 No.11

In view of the problem that local temperature of the original cylinder head is on the high side, an innovative cooling air diversion channel is proposed. The cooling air diversion channel introduces cool air into the cylinder head to forcedly cool the cylinder head. Furthermore, the multiple guide plates are set to reasonably distribute cold air in the air diversion channel. In addition, appropriately increase the length of the fins to cooling the whole cylinder head. The fluid-solid coupling three-dimensional simulation technology is adopted to analyze the impact of the new air diversion channel on the heat dissipation of cylinder head. Finally, the optimal scheme is defined to fabricate the prototype. Simulations results show that the above improvements make the temperature in the high temperature region effectively decrease, and the cooling performance of whole cylinder head is enhanced. In the optimal improvement scheme, the highest temperature of cylinder head decrease by 23 K. Furthermore, the prototype was fabricated according to the optimal scheme. The experimental results show that the temperature of the improved cylinder head decreased effectively, and the highest temperature decreased by 20.4 K. The simulation results are in agreement with the experimental results, and the maximum error is less than 5 percent.

Coordination polymer nanospheres: Preparation, upconversion properties and cytotoxicity study

Zhong, S.,Ji, Y.,Xie, Q.,Wang, L.,Li, Y.,Jeong, J.H. North-Holland 2013 Materials Letters Vol. No.

Coordination polymer (CP) nanospheres with diameters of 100-200nm have been successfully synthesized via a simple solvothermal approach employing glycol both as solvent and ligand in the presence of asparagine. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), inductive coupled plasma (ICP), thermogravimetric (TG) and differential thermal (DTA) analysis were used to characterize the products. Upconversion emission centering at about 676nm is realized in the coordination polymer spheres when excited with 980nm laser. Cytotoxicity study reveals that the coordination polymer nanospheres are biocompatible.

Investigating creep behavior of Ni–Cr–W alloy pressurized tube at 950 °C by using in-situ creep testing system

Zhong Yang,Lan Kuan-Che,Lee Hoon,Zhou Bomou,Wang Yong,Tsang D.K.L.,Stubbins James F. 한국원자력학회 2020 Nuclear Engineering and Technology Vol.52 No.7

The creep behavior of NieCreW alloy at 950 C has been investigated by a novel creep testing system which is capable of in-situ measurement of strain. Tubular specimens were pressurized with argon gas for effective stresses up to 32 MPa. Experimental results show that the thermal fatigue reduces the creep life of the tubular specimens and with the introduction of thermal cycling fatigue the primary stage disappears and the creep rate higher than the pure thermal creep (without thermal fatigue). Also the creep behavior of NieCreW alloy doesn't consist in the secondary stage. A new creep equation has been derived and implemented into finite element method. The results from the finite element analyses are in good agreement with the creep experiment.

Posbist Reliability Analysis of Typical Systems

Hong-Zhong Huang,X. Tong,L. P. He 한국신뢰성학회 2007 International Journal of Reliability and Applicati Vol.8 No.2

Filtered-based GPS structural vibration monitoring methods and comparison of their performances

P. Zhong,X.L. Ding,D.W. Zheng,W. Chen 한국항해항만학회 2006 한국항해항만학회 학술대회논문집 Vol.2 No.-

The purpose of GPS structural vibration monitoring is to obtain information on the frequency and amplitude of vibrations based on GPS observations that are often affected by various errors. Filters are frequently used to improve GPS accuracy and to retrieve vibration signals from GPS observational series. This paper studies the performances of four commonly used filters, i.e., Vondrak, wavelet, adaptive FIR and Kalman filters, for such applications. Controlled experiments are carried out and the results show that the capability of GPS in tracking structural dynamics and complex signals can be improved with any of the filters. The performances of Vondrak and wavelet filters are almost the same and superior to the adaptive FIR and Kalman filters. Recommendations are given for the selection of filters and filter parameters for different situations based on an analysis of the advantages and disadvantages of each of the filters.