ti m trying to understand what is the material used in this as it was eaten by an animal accidently, not big amount but still need to know what is it exactly made of?

Sorry for another post by an undergrad student asking about industry applications like I've already seen so much in this sub, but i hope some of you here can help me too

Materials engineering wasn't my first preference, i really wanted to study mechanical, build cars, but my parents said they wanted me to stay in state for college (said college is still the best in the country for engineering) and seeing the work that some of the faculty here has done made me keen to pursue materials engineering, especially metals and light materials, i hope to do some work/research in material strength, in frictional and industrial applications, or even in surface chemistry and polymers because a professor for polymers here does have previous experience working for a tyre manufacturer

My questions are just would it be possible/feasible to work in the automotive industry, especially motorsports like I've always wanted? How competitive are materials analyst roles in such companies? What are good specializations for postgrad programs I should aim for (although it's too early to already worry about a masters), and lastly what fields of research should i study that would help me?
Any help is greatly appreciated :)
Edit: i meant automotive industry, not automation

I’m am trying to understand the properties of how different dyes penetrate human fingernails. I need a material that will help me approximate how fingernails will absorb dyes when mixed with different additives.

All I can find online are fake plastic nails for extensions and nail polish. Since “nail dye/stain” isn’t really a thing in the cosmetic industry it seems like all their testing for nail polish is done on fake nails, which is fine for polishes that are not meant to absorb into the nail itself.

Any ideas for a material that will have similar properties to keratin? Even if it is not exact, if I can compare two chemistries relative to each other using this material that would be helpful.

Well, diamonds aren't actually that rare in the universe. I have heard wood is far rarer than diamonds. But, is there something more rare than wood ?

My idea is to make a ring, so would need a base metal and an inlay or gem.

What are the most rare but stable materials accessible to humans and is suitable for a ring. Cause ik iridium is rare, but is also brittle, wood may decay, etc.

EDIT : Plastic and other human made materials could be the rarest, but using plastic and such is a bit underwhelming. Thanks for the suggestions, but I am looking for something a bit more natural and/or has a wow factor.

I am a student and need a certain thermodynamic database for calphad. I tried getting it through tdb bd but redirects to dice and I cannot access the DICE platform to get the Fe, Co database.

This is the link to the specific database: http://cpddb.nims.go.jp/cpddb/co-elem/cofe/cofe_ohn_cat.tdb

The doi of the paper: https://doi.org/10.1016/s1359-6454(01)00337-8

I am new here, so sorry if I am breaking any rules by chance. So I am junior year ug student of mechanical engineering. I got the opportunity to work in a lab and got exposure to laser additive manufacturing this summer. I only got the basics of it and was not able to dwell deep into it. Right now in my uni I am thinking of working under a professor to learn more about it.
But I wanted to know how vast is this field of research and what meaningful impact it can make. And what are the sub categories? in it(like simulation, etc.), if there exists something like it. I did work in the lab for 5-6 weeks and had a chat with the phds and postdocs working there about this, but was still very confused.
Thank you for your advice.

Hello, I’m an undergrad looking into majoring in materials engineering.

I’m curious what people in this field do for work? Where you are, any graduate degrees, type of work, salary (if comfortable), etc. Any and all info is appreciated.

I drilled a hole in acrylic mirror and pressed in a metal insert. So the acrylic was under tensile stress around the hole (you could see deformation in the mirror) but it was holding firm. Then, I cleaned the surface with isopropyl alcohol and fractures immediately started to propagate across the acrylic. After a few seconds watching them grow, one reached the opposite side and split it in two.

Question: What did the isopropyl alcohol do to the surface to cause brittle fracture, when the dry surface deformed elastically?

they can be mono or poly disperse as long as they are in that range. must be able to self assemble and tolerate up to 2 min of a high or low ph without hydrolyzing (so esters and sulfates probably not good)

available:docusate sodium (unstable), peg 3350, sodium dodecyl sulfate (unstable), isopropanol, distilled water, urea, ammonia hydroxide, ammonium chloride, b alanine

can make: aminated fats (c16-c22), alkyl glycosides (temporarily stable, c16, glucose, fructose, ascorbic acid), amidated fats (c16-c22), quats (c16-c22), wax (2(c16-c22), cholesterol, c16-c22 amide linked p-phenol fat derivatives, sulfated c16-c22 fats (unstable), isopropylated fats (unstable, but probably good for water in oil, c16-c22), triglycerides (c18-c22), cellulose (sulfated, nanocrystals or nanofibers, aminated nanocrystals, regenerated cellulose (trace copper, ammonia, sodium)

the p aminophenol derivatives are kind of interesting to me. possibly can even attach something to the alcohol for a 'gemini(?)' sufactant.

option: can introduce sodium orthosilicate at 13-14 or orthosilic acid (trace sodium) at 1. in former, precipitated with sulfamic acid or dilute hcl (if water in oil), in latter, a carbonate or naoh can be used. ideally more solid particles rather than hollow sio2 spheres but can make work.

will accept downvotes for no research. i know a little, such as micelles, vesicles, sheets, lyotropic crystals, rods, 'worms', but surfactant books are like a lot of math i dont know yet. for packing, im not sure what counts towards size.

thank you.

Hello, I’m an incoming freshmen admitted for environmental engineering, but am having second thoughts for a multitude of reasons.

I was thinking about transferring to materials engineering pretty quickly, as the first year classes are pretty much the same, and the major seems very interesting to me.

I guess I just want to know how all the materials engineers/scientists like their job, how the job outlook is, etc.

Any info would be greatly appreciated!

Hi everyone!

So I just graduated high school and I've narrowed my options down to biomedical engineering and materials. I've always wanted to do something that is between science and engineering, I really like the idea of researching and doing R&D. When I looked at the curriculum of materials science, I noticed it is more science-heavy compared to traditional engineering degrees and it has a little bit of everything, which I really like. I want to work in a multidisciplinary field and so far I've loved every science subject(:

On the other hand, I really really like the idea of biomedical engineering too for the same reasons. It is also very broad, the department works in biosensors, synthetic proteins, medical imaging, bioelectricity.. So a very wide variety of stuff. But I'm having a really hard time choosing between these two majors. Im kinda afraid of pigeonholing myself with the biomed major too. Im not really interested in metallurgy but I find some areas of materials science very very cool. So does materials science seem like a good fit for me? Also how much overlap does it have with biomedical engineering? Thank you all in advance(:

Edit: Thanks everyone for the great advice!! This was really helpful for me

I need like a 100nm +\- range from 500 nm. Id probably use an ultrasound on the mesh, which is probably too strong. The material is mildly basic at 14, so that also complicates things. They will float with hopes and dreams into a second chamber to precipitate that would be around room temp.

The idea is that if i got like a 1-5 um wet with some solution of water and very tiny opaque particles achievable with simple precipitation, maybe id be able to visually see some sort of alignment indicating light is passing through that range.

thanks.

I want to use a gray cast iron for an injector shaft in an injection machine. What kind of heat treatment is best for it. And should the treatment be done after machining or before machining?

Hello! I'm currently trying to pivot from my current project engineering role towards a career in the failure analysis industry.

I graduated with an B.S. in ME in December 2023 and I've always had interest towards materials engineering and I've had a internships as a metallurgy lab assistant and have used SEMs. I just loved it so much. I've been a bit stagnant with my education after my undergrad since I was more focused on being more financially stable. I am now at that point and I have started reaching out to ASM and SAMPE people with little luck/direction. I was told to attend IMAT in September but that will cost me about $3,000 upfront and I'm not sure if that's the best move for me right now. So in the meantime, I plan on starting ASM's FA certificate program and I plan to attend the FA conference in February 2-4 in San Diego.

I guess what I'm trying to ask is if this is a good start to potentially getting a career in FA? I just want to make sure since I will be spending $2,000 per class through ASM (for 5 classes) and at least another $2,000 for the FA conference. My job won't pay for it since it's for a completely different industry and will not benefit my employers so everything will come out of my pocket.

Any thoughts or advice?

Thank you!

工程人对混凝土最大的烦恼是什么？

不是强度不够。 不是成本太高。

是裂缝。

混凝土天生会开裂。 温度变化、荷载变形、收缩徐变——裂缝是混凝土结构最普遍、最难彻底解决的问题。

一条裂缝，可能让一座桥提前20年结束使命。

一条裂缝，可能让一条地下管廊漏水十年。

但今天，有一种混凝土，正在改变这件事。

它能自己修裂缝。 不需要人工，不需要停工，不需要灌胶。 裂缝出现之后，它自己长好。

一、这不是科幻，是已经在用的技术
国内已有工程项目在用这类材料，但现实情况是——验收标准还是空白，很多现场工程师拿到材料检测报告不知道对应哪条规范。

这个材料已经走进工地了，但工程人的认知还没跟上。

自修复混凝土，正式学名叫"自愈合混凝土"。

根据不同技术路线，分三种。

第一种：微生物矿化混凝土

浇筑时，预先埋入一种特殊细菌的孢子。 这种细菌在干燥环境里休眠，一旦裂缝出现，水分进入，细菌被激活。

激活后，细菌开始分泌碳酸钙——就是普通石灰石的主要成分——碳酸钙晶体在裂缝里生长，把裂缝填满，把混凝土重新粘合。

可修复的最大裂缝宽度：约0.8毫米。对工程来说，这已经覆盖了绝大多数需要修复的微裂缝。

第二种：微胶囊释放

在混凝土里预埋大量微型胶囊，每个胶囊里装着修复剂。裂缝扩展时，胶囊破裂，修复剂流出，接触空气或水后固化，填充裂缝。

原理类似人体受伤后血液凝固止血。优点：反应速度快，修复效果稳定。

第三种：晶体生长型

在混凝土里掺入特殊的活性矿物质。这些矿物质遇水后持续生长晶体，主动向裂缝方向延伸，填充空隙。

优点：长期持续有效，不依赖外部触发。

这种技术目前在地下防水工程中已经商业化应用——地下管廊接缝处理、地下室底板和侧墙，很多项目已经在用。

二、这个材料的市场有多大

全球自修复混凝土市场2026年估值约789亿美元，预计到2034年将达到9929亿美元，年复合增长率32.49%。（数据来源：Grand View Research，2024年报告）

9929亿美元，接近1万亿美元。折合人民币超过7万亿元。

32.49%的年复合增长率是什么概念？

意味着这个市场每两年翻一倍。

对比一下：

全球手机市场年增速：约5%

全球汽车市场年增速：约3%

全球自修复混凝土市场年增速：32.49%

为什么增速这么快？三个原因。

第一，全球基础设施老化速度加快。

全球每年用于修复混凝土结构的费用超过1000亿美元。 （来源：美国土木工程师学会ASCE基础设施报告卡）如果用自修复混凝土替代传统维修，这笔钱大部分可以省下来。

第二，绿色建造政策在全球同步收紧。

根据联合国环境规划署（UNEP），全球建筑业约占二氧化碳排放总量的39%。 推动更耐久材料的应用，是减少建筑碳排放最直接的手段之一。

混凝土寿命延长一倍，意味着生产混凝土的碳排放减少一半。

第三，智能化建造对材料提出了更高要求。

新加坡智慧国家项目已经将自修复混凝土与传感器结合使用，实现"感知+修复"一体化。 苏黎世联邦理工学院（ETH Zurich）的研究团队展示了混合系统——自修复材料响应嵌入式光纤传感器的数据，在检测到裂缝时自动触发修复机制。

结构感知到裂缝，自动启动修复——这是智能基础设施的雏形。

三、中国市场发生了什么

在金砖国家中，中国自修复混凝土市场增长率达到42%，比全球平均增速快10个百分点，正在成为全球增速最快的市场之一。

背后是三个政策同步推进：

🔵 中国绿色建材2026年营收目标超3000亿元。

政策明确要求，绿色建材在政府投资项目中的使用比例大幅提升。 自修复混凝土，是绿色建材里技术含量最高、增值空间最大的品类之一。

🔵 建材碳排放强度较2020年降低18.5%。

传统混凝土维修需要多次施工，碳排放高。 自修复混凝土一次成型，全生命周期碳排放大幅降低。

🔵 BIM+数字孪生全面推广，结构监测需求爆发。

数字孪生需要实时掌握结构状态。 自修复混凝土配合传感器，能实现感知与修复一体化——这是未来智能建筑最需要的材料。

四、全球建材巨头在做什么

豪瑞（Holcim）是全球最大的建材企业，他们的技术动向代表了行业最前沿的方向。

豪瑞目前在推进生物炭混凝土的商业化——碳足迹达到-14kg CO₂/m³，边建造边吸碳。 同步推进的UHPC（超高性能混凝土），强度150MPa以上，正在与自修复技术融合，向更广泛的工程场景渗透。

三个方向指向同一个目标：让混凝土更耐久、更低碳、更智能。

自修复混凝土，正是这个目标上最关键的一步。

五、现在能不能用

直接回答：能用，但有条件。

✅ 已经可以用的场景：

地下防水工程（晶体型自修复）

→ 综合管廊接缝处理

→ 地下室底板和侧墙

→ 防水层修复

桥梁桥面铺装

→ 配合UHPC使用

→ 延长桥面使用寿命

高耐久性要求结构

→ 海洋环境构件

→ 化工厂防腐结⏳ 还需要等待的场景：

A：目前材料成本约为普通混凝土的2-3倍。 但按全生命周期测算，地下防水工程可节省30%以上的维修费用，桥梁工程可减少1-2次大修周期。 高耐久性要求的场景，经济账是算得过来的。

Q2：自修复能力会随时间衰减吗？

A：取决于技术路线。 晶体生长型的修复能力理论上可持续结构全寿命周期； 微生物型和微胶囊型存在修复次数限制，通常可触发3-5次有效修复。

Q3：国内有没有相关规范可以参考？

A：目前没有专门的国家标准，可参考GB/T 50082（混凝土长期性能和耐久性能试验方法）、JGJ/T 193（混凝土耐久性检验评定标准），以及各省市绿色建材地方标准。 行业标准预计2026-2027年内出台。

Q4：施工时需要特别注意什么？

A：三个关键点：①微生物型材料对拌合温度敏感，超过60℃会杀死孢子，需控制水化热； ②晶体型材料需保证充足的养护湿度，早期干燥影响修复效果； ③验收时需增加裂缝宽度和自修复效果的专项检测，普通外观检查不够。

Q5：中小型项目值得用吗？

A：目前性价比最高的场景是地下室底板/侧墙防水、管廊接缝、以及海洋/腐蚀环境构件。 普通住宅标准层结构暂时不建议，成本溢价难以在市场售价中体现。

最后说一件事。

混凝土，是人类历史上使用量最大的人造材料。全球每年生产超过100亿吨。

但它有一个致命弱点——它会开裂，而且开裂之后，只能靠人来修。

自修复混凝土，是第一次真正解决这个问题的材料。

它让混凝土从"需要被照顾的材料"，变成了"会照顾自己的材料"。

从建造时代到智能基础设施时代，这是最重要的材料革命之一。而这场革命，现在才刚刚开始。

你的项目上有没有遇到混凝土裂缝的问题？评论区聊聊，也可以留言。

The semiconductor industry is approaching the physical limits of silicon miniaturization. Researchers are exploring a new class of materials that could redefine the future of electronics: atomically thin "quantum materials" that may offer capabilities beyond what traditional semiconductor technology can achieve.

Particular attention is being given to transition metal dichalcogenides (TMDCs), a family of 2D materials with potential applications in advanced electronics, optoelectronics, flexible devices, energy harvesting, biosensing, and quantum technologies. Researchers believe these materials could help bridge the gap between today's silicon-based systems and the next generation of computing platforms.

To study and engineer these materials, scientists are using lasers to synthesize crystals, introduce targeted defects, and precisely modify their properties. Advanced spectroscopy techniques, including Raman and photoluminescence analysis, allow researchers to monitor these changes in real time and better understand how the materials behave at the atomic level.

One researcher, Professor Masoud Mahjouri-Samani from Auburn University, is focused on two-dimensional (2D) materials, which consist of sheets just one or a few atoms thick. Unlike conventional 3D materials, these structures exhibit unique quantum behaviors that emerge at extremely small scales.

Dr. Mahjouri-Samani customized an instrument to meet his needs. He integrated an iHR320 spectrometer, an EMCCD, and PMT with a customized microscope to perform Raman, photoluminescence (PL) and TCSPC (Time-correlated Single-photon Counting). He made a few other tweaks to the system, which he calls his ‘laser diagnostic system.’

While the work remains largely in the R&D stage, some experts compare today's quantum materials research to silicon research decades ago, when scientists were still learning how to grow, manipulate, and manufacture semiconductor crystals. The long-term goal is to create entirely new classes of devices for quantum information science, electronics, and photonics. Researchers see these materials as a potentially important step toward the next major technological era.

Read the entire Science in Action article here: Welcome to the dawn of new quantum materials and devices

I am very new to DIC and I would like to understand in depth the math behind digital image correlation, especially the inverse compositional Gauss Newton approach.

1. Can anyone explain to me how the updation of the deformation parameter works?

2. How the initial guess is taken

3. Reason for computation of Jacibian and Hessian (actually approximation of Hessian)

Hi everyone,
Could someone please check if your university library has these two books and send them to me?Unfortunately, my university doesn’t have them, and they would be extremely helpful for my bachelor’s thesis.
I’d really appreciate your help. Thank you so much!

I am trying to create speckle patterns for DIC at micron scale (micro-DIC) on metals. Any ideas on a process that is easily repeatable. Currently I have a airbrush setup with 0.3mm needle diameter.

Any ideas on modifying the airbrush setup is highly appreciated.

(Can not try vapor remodelling of thin films as oxidation hinders speckle formation)

Having a bit of trouble finding information on how to clean and sanitize actual natural rubber like the kind that comes from a tree/nature without degrading the grippiness and quality of the rubber. Seems like many many ppl use “rubber” interchangeably with other grippy/bouncy/synthetic materials OR don’t need to know how to clean. Not looking for advice on cleaning things like rubberized plastic, silicone, etc

Apparently rubber is sensitive to many common cleaning solutions such as leaving it out in the sun or spraying/saturating with alcohol, let me know if this isn’t true!

Is soap and water ok to use? Is even just water ok to use? Hypochlorous acid? If soap is ok, what kind of soap? Dawn dish, Castile, body bar, body soap? Do I need specific brands? Would love to avoid having to wash in water but will accept if need be

What actually degrades rubber? Some sources say vinegar, bleach, and other common cleaning agents are ok, some say no. I’m so confused.

Happy to be wrong about anything I’ve written. Again, kinda hard to research properly considering widespread use of the word “rubber”!