Volume 12: Materials: Genetics to Structures最新文献_第4页

Functionalized Cellulose Nanocrystals for Improving the Mechanical Properties of Poly(Lactic Acid) 功能化纤维素纳米晶改善聚乳酸力学性能

Volume 12: Materials: Genetics to Structures Pub Date : 2018-11-09 DOI: 10.1115/IMECE2018-87691

Jamileh Shojaeiarani, D. Bajwa

{"title":"Functionalized Cellulose Nanocrystals for Improving the Mechanical Properties of Poly(Lactic Acid)","authors":"Jamileh Shojaeiarani, D. Bajwa","doi":"10.1115/IMECE2018-87691","DOIUrl":"https://doi.org/10.1115/IMECE2018-87691","url":null,"abstract":"Biopolymers are emerging materials with numerous capabilities of minimizing the environmental hazards caused by synthetic materials. The competitive mechanical properties of bio-based poly(lactic acid) (PLA) reinforced with cellulose nanocrystals (CNCs) have attracted a huge interest in improving the mechanical properties of the corresponding nanocomposites. To obtain optimal properties of PLA-CNC nanocomposites, the compatibility between PLA and CNCs needs to be improved through uniform dispersion of CNCs into PLA. The application of chemical surface functionalization technique is an essential step to improve the interaction between hydrophobic PLA and hydrophilic CNCs. In this study, a combination of a time-efficient esterification technique and masterbatch approach was used to improve the CNCs dispersibility in PLA. Nanocomposites reinforced by 1, 3, and 5 wt% functionalized CNCs were prepared using twin screw extrusion followed by injection molding process. The mechanical and dynamic mechanical properties of pure PLA and nanocomposites were studied through tensile, impact and dynamic mechanical analysis. The impact fractured surfaces were characterized using scanning electron microscopy. The mechanical test results exhibited that tensile strength and modulus of elasticity of nanocomposites improved by 70% and 11% upon addition of functionalized CNCs into pure PLA. The elongation at break and impact strength of nanocomposites exhibited 43% and 35% increase as compared to pure PLA. The rough and irregular fracture surface in nanocomposites confirmed the higher ductility in PLA nanocomposites as compared to pure PLA. The incorporation of functionalized CNCs into PLA resulted in an increase in storage modulus and a decrease in tan δ intensity which was more profound in nanocomposites reinforced with 3 wt% functionalized CNCs.","PeriodicalId":119074,"journal":{"name":"Volume 12: Materials: Genetics to Structures","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117093194","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Effect of Micro (Banana) and Nano (SiC) Fillers on Mechanical Behaviors of Basalt/Epoxy Hybrid Composites 微(香蕉)和纳米(SiC)填料对玄武岩/环氧复合材料力学性能的影响

Volume 12: Materials: Genetics to Structures Pub Date : 2018-11-09 DOI: 10.1115/IMECE2018-86268

S. Santhanam, P. Sampath, Bharani Srikanth Ponnusamy, Mohan Bangaru

引用次数: 2

A Thermo-Electro-Elasto-Viscoplastic Damage Internal State Variable (ISV) Model for Ductile Metals 延性金属热-电-弹-粘塑性损伤内状态变量模型

Volume 12: Materials: Genetics to Structures Pub Date : 2018-11-09 DOI: 10.1115/IMECE2018-86598

N. Dimitrov, Yucheng Liu, M. Horstemeyer

引用次数: 3

Mechanical Properties of 3D Printed Biomimicked Composites 3D打印仿生复合材料的力学性能

Volume 12: Materials: Genetics to Structures Pub Date : 2018-11-09 DOI: 10.1115/IMECE2018-86309

S. Allameh, Roger Miller, H. Allameh

引用次数: 1

A Crack Detection and Evaluation Method for Self-Piercing Riveting 自穿孔铆接裂纹检测与评价方法

Volume 12: Materials: Genetics to Structures Pub Date : 2018-11-09 DOI: 10.1115/IMECE2018-88403

Xuyang Wang, Yudong Fang, Zhenfei Zhan

引用次数: 1

Influence of the Microstructure on the Creep Behaviour of Tin-Silver-Copper Solder 微观组织对锡银铜焊料蠕变行为的影响

Volume 12: Materials: Genetics to Structures Pub Date : 2018-11-09 DOI: 10.1115/IMECE2018-87789

P. Ribeiro, D. Soares, M. Cerqueira, S. Teixeira, D. Barros, J. C. Teixeira, P. Capela, F. Macedo

{"title":"Influence of the Microstructure on the Creep Behaviour of Tin-Silver-Copper Solder","authors":"P. Ribeiro, D. Soares, M. Cerqueira, S. Teixeira, D. Barros, J. C. Teixeira, P. Capela, F. Macedo","doi":"10.1115/IMECE2018-87789","DOIUrl":"https://doi.org/10.1115/IMECE2018-87789","url":null,"abstract":"A common failure mode of electronic printed circuit boards (PCB’s) is the appearance of cold solder joints between the component and PCB, during product life. This phenomenon is related to solder joint fatigue and is attributed mainly to the mismatch of the coefficients of thermal expansion (CTE) of component-solder-PCB assembly. With today’s solder joint thickness decreasing and increasing working temperatures, among others, the stresses and strains due to temperature changes are growing, leading to limited fatigue life of the products. As fatigue life decreases with increasing plastic strain, creep occurrence should have significant impact, especially during thermal cycles and, thus, should be studied. Through the cooling phase, on the production of PCB assembly’s by the reflow technology, the hoven atmosphere temperature is adjusted in order to control the cooling rate. Narrow criteria is used so as to control the inter-metallic compounds (IMC) thickness, PCB assembly distortion and defects due to thermal shock. The cooling rate also affects solder microstructure, which has direct impact on creep behaviour and, thus, on the soldered joint reliability.\u0000 In this paper, a dynamic mechanical analyser (DMA) is used to study the influence of the solder cooling rate on its creep behaviour. SAC405 samples with two distinct cooling rates were produced: inside a hoven cooling and by water quenching. Creep tests were made on three-point-bending clamp configuration, isothermally at 25 °C, 50 °C and 75 °C and under three separate levels of stress, 3, 5 and 9 MPa. The results show that creep behaviour has a noticeable cooling rate dependence. It was also noticed that creep propensity is exacerbated by the temperature at which stresses are applied, especially for the slower cooling rates. Creep mechanisms were related to the solder microstructural constituents, namely by the amount of phases ant their morphology.","PeriodicalId":119074,"journal":{"name":"Volume 12: Materials: Genetics to Structures","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132915845","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A Comparative Assessment of the Structural, Elastic and Electronic Properties of Nb3Pt and NbPt3 Phases Through First-Principles Study 基于第一性原理研究Nb3Pt和NbPt3相结构、弹性和电子性能的比较

Volume 12: Materials: Genetics to Structures Pub Date : 2018-11-09 DOI: 10.1115/IMECE2018-86911

R. Fono-Tamo, Jen Tien-Chien, O. Bhila

引用次数: 0

Localized Fatigue Response Evaluation of Weld Regions Through Cyclic Indentation Studies 通过循环压痕研究焊缝区域局部疲劳响应评价

Volume 12: Materials: Genetics to Structures Pub Date : 2018-11-09 DOI: 10.1115/IMECE2018-86420

R. Prakash, K. Madhavan, A. R. Prakash, Pankaj Dhaka

{"title":"Localized Fatigue Response Evaluation of Weld Regions Through Cyclic Indentation Studies","authors":"R. Prakash, K. Madhavan, A. R. Prakash, Pankaj Dhaka","doi":"10.1115/IMECE2018-86420","DOIUrl":"https://doi.org/10.1115/IMECE2018-86420","url":null,"abstract":"An experimental investigation of the fatigue response of commonly used structural stainless steel — SS 304 L(N) and SS 316 L(N) — and its weld was carried out through automated cyclic ball indentation (ABI). A Tungsten Carbide (WC) spherical ball indenter of 1.57 mm diameter was used for compression-compression fatigue testing of the specimen under load control at a low frequency of loading (typically 0.1 Hz to 1 Hz). The force-displacement response during fatigue loading was logged continuously during fatigue test and the data was analyzed to extract details such as variations in: total depth of penetration, loading and unloading slopes, loading/unloading intercept, displacement range as a function of number of cycles. From the results, one could identify an unsteady response of material during cyclic loading after some cycles of fatigue loading — typical of failure; this input was used to compare the fatigue response of different zones of the weld.\u0000 Even though the applied frequency of loading is relatively less (∼ 1 Hz), due to the high levels of plastic deformation that is developed during the indentation process, one could expect an effect of strain rate on the fatigue response during cyclic ball indentation. To verify this, experiments were carried out at three distinct frequencies of 0.1 Hz, 0.5 Hz and 1 Hz for a given loading condition. Further, it was observed that the material response in weld region is the best, followed by the base metal. This can be corroborated with the weld microstructure that is obtained as a consequence of processing. Frequency of loading did not have significant influence on the fatigue failure life.\u0000 Numerical simulation of cyclic ball indentation was carried out to extract some relevant parameters for failure life such as mean stress and local stress ratio. This will serve as input to correlation of failure life data obtained from conventional specimens.","PeriodicalId":119074,"journal":{"name":"Volume 12: Materials: Genetics to Structures","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122149429","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

First-Principle Investigation of Structural, Elastic, Electronic and Thermal Properties of Dysprosium Hafnate Oxides 铪酸镝氧化物的结构、弹性、电子和热性质的第一性原理研究

Volume 12: Materials: Genetics to Structures Pub Date : 2018-11-09 DOI: 10.1115/IMECE2018-87099

H. Niu

引用次数: 0