Open Access. Powered by Scholars. Published by Universities.®

Engineering Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 7 of 7

Full-Text Articles in Engineering

Processing And Mechanical Properties Of Hot-Pressed Zirconium Diboride – Zirconium Carbide Ceramics, Eric W. Neuman, William Fahrenholtz, Gregory E. Hilmas Sep 2022

Processing And Mechanical Properties Of Hot-Pressed Zirconium Diboride – Zirconium Carbide Ceramics, Eric W. Neuman, William Fahrenholtz, Gregory E. Hilmas

Materials Science and Engineering Faculty Research & Creative Works

ZrB2 was mixed with 0.5 wt% carbon and up to 10 vol% ZrC and densified by hot-pressing at 2000 °C. All compositions were > 99.8% dense following hot-pressing. The dense ceramics contained 1–1.5 vol% less ZrC than the nominal ZrC addition and had between 0.5 and 1 vol% residual carbon. Grain sizes for the ZrB2 phase decreased from 10.1 µm for 2.5 vol% ZrC to 4.2 µm for 10 vol% ZrC, while the ZrC cluster size increased from 1.3 µm to 2.2 µm over the same composition range. Elastic modulus was ~505 GPa and toughness was ~2.6 MPa·m½ for all compositions. …


Effect Of Boron In Cast Iron, Suyash Durendra Pawaskar Aug 2022

Effect Of Boron In Cast Iron, Suyash Durendra Pawaskar

Masters Theses

"Boron, mostly considered a residual element, has started to cause issues in the cast iron foundries by causing a decrease in the strength of pearlitic gray and ductile iron castings. Because of the increase in the use of boron-added steel scrap from automotive steel and a lack of agreement on the critical levels of boron in cast iron, foundries are facing difficulties in controlling the microstructure of gray iron castings when boron is present. The current investigation was designed to analyze the effects of boron in cast irons and predict a mechanism to understand its effects with a vision of …


Mechanical Properties And Microstructure Of High Strength Lc3 Pastes With Varying Limestone/Calcined Clay Ratios And Different Curing Conditions, Yemin Dong Jul 2022

Mechanical Properties And Microstructure Of High Strength Lc3 Pastes With Varying Limestone/Calcined Clay Ratios And Different Curing Conditions, Yemin Dong

International Conference on Durability of Concrete Structures

研究(抗施工蒸馏)石石和石榴石在淀粉胶系统(即0标准和低水印)下的水胶系统(即0标准和低水墨)X射线比、水量值水量-电子背基相关研究.61.25 .25.25.25.0.25.25.25.25.25.0.25.25.25.25.25.1.25.7.25.0.0.0.0.0.0.0.0.0.0.0.0.0.0.1.25.1.25.25.1.25.1.25.1.25.1.25.1.25.1 .25.1.25.1.25.1.25.1.25.1.25.0.0.0.0.0.0.0.00.0.0.1.25.1.25.1.25.1.25.1.25.0.0.0.00.0.0.0.0.0.0.0.0.0.0.0.0.0.00.0 .00.0.00.X射线比值、水量-电子显微镜相关研究测量值。早期的水泥水化程度小水的压合含煤量,降低了水泥石的。因此,需要采用合适的钙铝内容和体系以提高碳系统的性能。


Investigation On Structural Heritability And Durability Of High Sulfate Resistance Portland Cement Mortar Modified By Aluminum Salt, Jun Xu Jul 2022

Investigation On Structural Heritability And Durability Of High Sulfate Resistance Portland Cement Mortar Modified By Aluminum Salt, Jun Xu

International Conference on Durability of Concrete Structures

The essential hydration and hardened properties of high sulfate resistance Portland cement paste/mortar were investigated with Al2(SO4)3 as admixture. Experiment results showed that that the addition of Al2(SO4)3 promoted the hydration of HSRP cement pastes, and the hydration rate accelerated with the increase of the addition amount. The mechanical properties and chloride diffusion coefficient of cement mortar were obviously improved with 0.25% Al2(SO4)3 addition . For instance, the compressive strength of AS0.25 cement mortars was 24.8% higher than AS0 samples and the chloride ion migration …


Room-Temperature Mechanical Properties Of A High-Entropy Diboride, Alec C. Murchie, Jeremy Lee Watts, William Fahrenholtz, Gregory E. Hilmas Jul 2022

Room-Temperature Mechanical Properties Of A High-Entropy Diboride, Alec C. Murchie, Jeremy Lee Watts, William Fahrenholtz, Gregory E. Hilmas

Materials Science and Engineering Faculty Research & Creative Works

The mechanical properties of a (Hf,Mo,Nb,Ta,W,Zr)B2 high-entropy ceramic were measured at room temperature. A two-step synthesis process was utilized to produce the (Hf,Mo,Nb,Ta,W,Zr)B2 ceramics. The process consisted of a boro/carbothermal reduction reaction followed by solid solution formation and densification through spark plasma sintering. Nominally, phase pure (Hf,Mo,Nb,Ta,W,Zr)B2 was sintered to near full density (8.98 g/cm3) at 2000°C. The mean grain size was 6 ± 2 µm with a maximum grain size of 17 µm. Flexural strength was 528 ± 53 MPa, Young's modulus was 520 ± 12 GPa, fracture toughness was 3.9 ± 1.2 MPa·m1/2, and hardness (HV0.2) was 33.1 …


Production Of Low-Cost Self-Consolidating Concrete (Scc) Using Manufactured Aggregates, Rabab Raydan, Farah Chamseddine, Ali Jahami, Oussama Baalbaki, Jamal Khatib, Adel Elkordi Jun 2022

Production Of Low-Cost Self-Consolidating Concrete (Scc) Using Manufactured Aggregates, Rabab Raydan, Farah Chamseddine, Ali Jahami, Oussama Baalbaki, Jamal Khatib, Adel Elkordi

BAU Journal - Science and Technology

Limitations to the sources of aggregates and the unavailability of sand is becoming a problematic issue for concrete production. A novel technology of manufactured aggregates can produce well graded round aggregates that can substitute natural aggregates while maintaining the same characteristics needed and preserving the resources. Self-Consolidating Concrete (SCC) using manufactured aggregates is assessed in this experimental work to understand the variability of workability properties and mechanical properties with the changes in w/c ratio and percentages of Coarse Aggregates and Manufactured Sand to Natural Sand in order to choose the best mixture that satisfies an adequate overall performance. Targeting compressive …


Insect Antennae As Bioinspirational Superstrong Fiber-Based Microfluidics, Griffin J. Donley May 2022

Insect Antennae As Bioinspirational Superstrong Fiber-Based Microfluidics, Griffin J. Donley

All Theses

Nature is frequently turned to for inspiration for the creation of new materials. Insect antennae are hollow, blood-filled fibers with complex shape, and are cantilevered at the head. The antenna is muscle-free, but the insect can controllably flex, twist, and maneuver it laterally. To explain this behavior, a comparative study of structural and tensile properties of the antennae of Periplaneta americana (American cockroach), Manduca sexta (Carolina hawkmoth), and Vanessa cardui (painted lady butterfly) was performed. These antennae demonstrate a range of distinguishable tensile properties, responding either as brittle fibers (Manduca sexta) or strain-adaptive fibers that stiffen when stretched (Vanessa cardui …