Manufacturing Process Mechanics - Science topic

Dear Alireza Taheri, please refer to the following documents for better understanding of the contribution of both: PDMS and SiO2, to the contact angle changes. My Regards

Use high pressure water Descaler. Most of forgings and steel producers are using to remove scale from heated billets / slabs.

Water spray @ 200 bar is applied through flat jet nozzles. This reduces billet / slab temperature @ 5 to 10 degree, which is acceptable in these process.

post heat treatment is the simplest method to restructure the grain growth in heat affected zone

I fully agree with Daniel Martinez Krahmer

PVD coated tools or inserts are more suitable for machining stainless steel. PVD technique enables suitable coverage of the sharp cutting edges as compared to CVD and retention of the coating on the cutting edges.

in several paper about grey relational analysis combined with taguchi methode , I found initial parameter design to compare predictive value in confirmation test . For example : initial factor A1B2C2D1 compare with optimal result A2B2C2D2. Anyone can explain how determine the initial parameter design or initial optimal faktor? I really confuse about this.... Thank you

They have same performance level in industry. Both of them used as a blasting process. Differences in term of materials one jet is good for machining and one use powder for blasting.

Hi Jose and Ahmad

It is good to discuss about the required tools to get mathematical equation for pin Geometry in FSSW.

My Skype: raheem.khagani

Whatsapp: 009647706746363

Annealing of the material before the machining will definitely help to reduce the mentioned property or else try the cryogenic machining 

What's the problem? Do you want to use it at high temperature? Mg alloys are not as easy as pure Mg flammable. Be the way, if you use Mg as a bulk part it you wont be worry about flammability.

here is an example of flame-resistance Mg base alloys.

Dear.

Before giving an answer to your question : "How to evaluate the integration at the design stage for the evaluation of the product"

I ask the following question :

What is concerned by "Integration" in your question ?

Can you detail more your question?

Yassine B.

If you are looking for high-nickel electrode you migth check NiCro 31/27. If your parts operate at temperatures below 200C you might consider braze welding using e.g. CuAl8 or CuZn, etc. However, In my opinion the cheapest solution, which might work, will be use of an austenitic stainless steel grades such as 304 (AWS 308, ISO 14343-A: G 19 9 L).

Good luck.

I used a 304 that is very common and easy to manufacture. Thank you everybody for the help

Daniel: hay un sitio interesante: http://www.practicalmachinist.com/; también una publicación:

MACHINING OF HADFIELD STEEL : AN

OVERVIEW   Orhan Cakir

 que se puede bajar de internet .

Suerte

Reinaldo

HI Pablo, I didn't arrive at a satisfactory solution to my specific issue. And switched job after a while, so I can offer too much  help.

Thank you Sir. 

I will try to calculate as suggested by you.

Will write you the results....

Thank you so much

Kind regards 

I do not see how you can estimate the age of such specimen based on the information you provide. It would be easier to answer your question if you trace the origin of the specimen based on information of the infrastructure from which you took the sample.

Hi Selvaraj,

The tool is not supplied by any supplier, rather it is easy and cheap to produce the tool on CNC lathe. For flat-end and hemispherical you can even use conventional lathe. One of the main consideration is which tool material to use. Generally speaking, the tool material hardness should be higher than that of metal sheet material that you want to use. 

Hope this answers your query.  Have a nice time experimenting.

First, you have to search some theorical and practical courses and workshops for the SLM process.Then try to search scientific papers on the optimization of machine parameters.Know how the machine really works and how each machine parameter affect the quality of the parts is,for me, mandatory.I can reccomend you some papers if you write me in private.

I agree with Omar (direct metal printing)  But there is another form of additive manufacturing through 3D printed sand molds and casting. This would give better properties. ExOne or Voxeljet printers.

Since the point of view of the material, the built up edge formation can be reduce by using alloy elements like Pb, Bi, Te, and Ca.

Since of machining point of view, you can use coated inserts. This type of tool reduce the built up edge formation.

 Dear Sudhir Kumar

FSW  uses to join 6.3 mm (1/4 in.) thick sheets of polypropylene (PP), polycarbonate

(PC), and high-density polyethylene (HDPE) materials (Fig. 13.41). Recent work at

 has shown joint efficiencies for these materials ranging from 83% for PC to 95% for HDPE and 98% for PP. These joint efficiencies compare favorably with other polymer

joining methods such as ultrasonic, solvent resistance, hot plate, and adhesive bonding.

The very simple method to identify the temperature of sit zone is by using a Thermal Imager.

I'm sorry for my reply, that's result is based to water quality test,

 Ok. Thank's. Whether this area to be the maximum gradient of the transition from compressive to tensile stress? 

Material properties:

Design Tensile Strength 4.8x10 7 Pa (N/m2) (7000 psi)

Design Compressive Strength Greater than 1.1 x l0 9 Pa (160,000 psi)

Bulk Modulus 3.7x10 10 Pa (5.3x10 6 psi)

Rigidity Modulus 3.1x10 10 Pa (4.5x10 6 psi)

Young's Modulus 7.2x1 -10 Pa (10.5x10 6 psi)

Poisson's Ratio .17

Dear Parmar. It is very interesting as usually people ask about how Supply Chain Affect Manufacturing. I would recommend the following books for further reading:

1. The Supply Chain in Manufacturing, Distribution, and Transportation: Modeling, Optimization, and Applications by Kenneth D. Lawrence (Editor), Ronald K. Klimberg (Editor), Virginia M. Miori (Editor).

2. Supply Chain Management and Optimization in Manufacturing by Harun Pirim, Umar Al-Turki, Bekir Sami Yilbas.

3. Manufacturing Planning and Control for Supply Chain Management by F. Robert Jacobs and William Berry

4. Manufacturing Planning and Control Systems for Supply Chain Management by Thomas Vollmann and William Berry

Happy reading...

 Dear Sir,

I hope that following links could helped you in your project.

Also, you can use the information from book: 

Best regards,

For me is not possible, for al last two reasons: the geometry of the sample test (cylindrical) and because the ring test involve a volumen of this sample.

I would like to thank you all for have spending your time to answer my question.

Best regards

Jorge Vilhena

If you have a model, try to do a curve-suface fitting before interpolation.

For rough initial data, review

and the fortran code of rutines companion

My question is why at the specific place in Ball thread area. 

140 KW  begins from the bottom of the ball thread area and the coil move upwards, the soft zone arise only at that place. 

Local/ Global approach is a variant of inherent strain method. In fact, in FE analysis of welding distortion, the shell elements are used in bulk of the structure replacing the local weld zone by equivalent boundary conditions (updated or not in successive analysis steps). The stresses and distortion so produced are analyzed under the assumption that local collapse (buckling) does not occur. The problem with resistance welding is that the sheet is so thin that buckling is imminent. Prediction of buckling (and consequent distortion) is so difficult and uncertain that no such attempts have been made (at least I am not aware of it in spite of vast literature on distortion in welding which i have read in connection with my projects on distortion in welding). The only references on buckling distortion are the experimental findings on the welding conditions (arc or laser etc.) beyond which buckling occurs for a particular plate thickness (see reference)

25. Terasaki, T., Effect of welding conditions on residual stress distribution and welding deformations in welded structural materials, Proc. 12th Int. offshore and polar engg. Conf., Kitakyushu, Japan, May 26-31, 2002, p 332-336.

Yes, it is vaporization temperature.

Dear friend

The book by professor Kurt Lange is awesome.Also, ASM has the very brilliant handbook,I think vol14 on forging.Personally, I prefer the old version.

Link for professor Lange's book:

Dear Anantha Dv

You can avoid this with:

1. Low heating rate and low drying temperature, as far as possible

2. Reasonable drying curve, for example some gelling agents are susceptible to 50-70^oC so high heating rates at this temperatures can result in lamination

3. Proper aging conditions, inappropriate aging can be the cause of drying defects

4. Broad and continuous particle distributions.

5. Coarser grains (if possible). The coarse aggragates act as anti-cracks.

6. Organic fibers as drying aids (if possible), that can burn under water boiling temperature (110^oC) and so on help the evaporation

7. Various gelling agents such as Hydratable Alumina

8. Dispersant and deflocculant agents to reduce mixing water and help the drying procedure

Lean is about how to eliminate waste of maintenance process

Hi Sanjay,

The density or porosity of the sintered samples can be measured according to ASTM standard B962-15 which is based on Archimedes' method. The steps to perform this method are very simple.

1. Boil the samples for 40 mints in distilled water for degassing purposes.

2. Immerse the samples in the water to fill out any pores. and check the immersed weight = w1

3. take out the immersed samples and tap off the water from the top bottom surfaces gently and measure the weight , w2.  

3. dry the samples in an oven for 1 hr and note the weight, = w3.

then make the following calculation:

exterior volume of samples , V =  (w3-w1)/ density of water (~1.0 g/cc)

Bulk or Archimedes density = (w3)/ V

Volume of pores , vp = (w2-w3)/density of water 

Apparent porosity (%) = vp/V 

Relative density (%) = Bulk density / theoretical density. 

In order to preform such method you need to get an equipment/set-up as you can see in attached image, which is very simple to make or use.

Hope it helps.

Good luck,

Khurram

Dear Sir, Thanks for the references. I'll check them. 

I know how to make the tool - its exactly same as that for CD/DVD. You take a glass plate, coat it with photoresist, shine laser, develop it. Then vaccum deposit metal (200nm thickness) on it, then electroplate it with Nickel to a thickness of 300um. This Nickel plate has all the features (though complimentary) that were present initially on the glass sheet.

Making the nickel 'stamper' is clear to me. My concern is the (extent of) stringent control during the production of plastic component during moulding. Would the features remain intact during the cooling, or would they merge with each other spoiling the details?

As per Standard ASTM D1002

You need

*Section Controls, name=EC-1, ELEMENT DELETION=YES

1., 1., 1.

and a failure criterion on you material

You also need to define the whole workpiece as a possible contact surface so that newly generated surface can be in contact with your tool, something like

*Surface, type=ELEMENT, name=interior

s_Set-4, interior

*Contact Inclusions

interior, toolsurf

I'm not using CAE for these things so I cannot tell how to do it there.

Hope this helps,

Martin.

Hi Deepak,

What exactly do you want to sense using a HSC? Do you want to visualise the arc plasma geometry or something else?

If you want to visualise the arc plasma geometry use a Bandpass filter in the NIR (maybe 700-800 nm) region along with a halogen lamp with sufficient intensity at that wavelength. This should give you clear pictures of the arc plasma.

Regarding the frame rate, even a frame rate count of 1000-2000 will give you sufficient idea about the process and hence it is important to consider what you want to see and then calculate the frame rate in a sense that particular event is captured within a single frame.

Yes of course it would be very useful to record the arc electrical characteristics using an  oscilloscope by synchronising it with the camera.  

You may use Failure Mode Effective Analysis (FMEA) tools to identify critical and the severity of the barriers. By weighting on the occurrence and severity level in manufacturing, you may get the top 3 or 5 barriers that matters. 

The quartz will run with HK(percholoric acid+ammonium nitrate) etchant to remove the chrome layer on the quartz. But the problem is this HK will leave stain and particle(residues) that stick to the glass and hard to be remove if if dry on the quartz.

So I need to find the detergent that absolutely can kill this HK residues that stick to the glass.

Hello Mr Shabbir,

If I have understood your question right and read your explanation it could be that you mixed up some things.

In my understanding its

Hydraulic cylinder :

p(hyd)= F/ A(cylinder)  with the area of your cylinderpiston

Surface Force Stamp:  

Sigma(surf.press)= F/ A(pressing area)  -> F = sigma * A(pressing area)

Thus:

p(hyd)= sigma(surf.press) * A(pressing area) / A(cylinder)

A(pressing area) / A(cylinder) = K (constant)

Thus:

p(hyd)= sigma(surf.press) * K

Now you can translate your p(hyd) from you gauge into a Surface pressure which exists at your stamp.

regards,

Kamil Wlotzka

plasma assisted metallic coating

I was looking for something similar and I came across a paper which might be helpful. Please check http://www.sciencedirect.com/science/article/pii/S1877705813001999

This general question can naturally not be answered in two or three sentences. The correct answer is already that the surface roughness and the wear of the selected process parameters depend.

The corner or edge wear is the main factor for a high machining accuracy, which has its cause in the fact that at the edges of the inhomogeneous electric field strength becomes the greatest and in this region the purge no longer is usually ideal.

The percentage is the wear of the removal rate is dependent on several things. A basic trend is that with short pulse durations of wear greatly increases and decreases for long pulse durations or is constant. One reason is that the main effect of the wear arises upon ignition of the spark. For these reasons, separate ignition modules are used, the only to have a minimum current.

Now you can still explain some more effects and still consider how large the working surface is and how effectively acts flushing, ......

Corresponding publications can be found in my reading list or for special designated applications can discuss it in more detail.

Dear, I second Mr. Jie Liu on this but I'd be able to comment on this if you describe your problem in detail. Specifically, the constraints you have in this problem.

Dear Daniel

My Bad, I talk about chip.

Thanks

In FSW, there are some changes in microstructure features along FSW tool's movement, but these changes are local and periodical. These features can be seen as band structure in longitudinal section. Although this inhomogeneity is local, it can make difference between two cross sections. In order to ensure whether the microstructure is uniform at whole of the FSW tool's path, you can observe the microstructure in longitudinal section.

Dr Schulze is right. I think that we have more than one question here:

1) what is the available energy for each pulse

2) wire breakage

1) has been answered already.  What I can add is, there is a power loss along the wire if the current pickup is not close to the spark.  When one measures the discharge voltage on a WEDM machine, it shows 50 to 70 V, whereas we know that it is  really about 20-30 V. The additional 30-40V are caused by the voltage drop on the wire (and energy loss)

Another aspect is the workpiece material. Here the relevant parameter is the specific resistance. This gives you the power loss in the workpiece (Ohm's law)

2) wire breakage keeping constant generator settings can have many causes:

- insufficient flushing (air bubbles ? variations in the pressure, flow?)

- wire advance speed variations

- geometry of the workpiece

- concentration of the discharges in one spot. One could read the excellent work of Dr Dekeyser "knowledge based system for WEDM" where he discloses a good Thermal model to predict the wire breakage  (PhD dissertation from Katholieke Universiteit Leuven, 1988)

Dear Justin, If you cannot measure those parameters you should fix them as nonvariable factors. By changing the DOE method you cannot eliminate the mentioned factors.

using ANSYS APDL is quite forward. first of all you have to know the position of your heat source. based on that you calculate the affected volume - with that information you know which nodes of your model are within the area of heat input. Each node represents a certain volume. by integrating the volume of all affected nodes you get the affected volume (this is only for checking the correctness of your calculation). However, in the same way you calculate the heat distribution: at the position of each node you can calculate the specific heat input q_i(x,y,z,t) and multiply this with the affected volume V_i. to check the result the sum of q_i times V_i must be the total heat input.

To realise this in APDL you have to know the variables of your element (node number, node coordinates) including free variables where you can apply the heat input.

hope this helps

@martin baeker

thanx for the idea.. it seems to have memory issue as you suggested

friction stir  welding may be suitable

Spacibo Yury,

Do you have an article in English as well?

R ni garasho govarit par Ruskii....

There can be a number of parameters which can be studied depending on what you are trying to analyse.

If you plan to grind a WC insert and use it as a cutting tool during  say, straight turning, you may want to check its residual stresses as chances are that compressive residual stresses are induced in the WC insert. Incorporation of compressive residual stresses usually improve toughness, which may help the insert during machining. You may also want to check about 'grind hardening' which may happen as WC grinding usually involves low values of depth of cut.

You have to consider the following:

1. Bearing mounting: How will the bearing be supported? using a housing? plummer block? What is the size of the shaft? etc.

2. Operating conditions: operation speed, duty, environmental factors (may require a sealed bearing)

3. Applied loads: Are the loads radial, or axial or both?

4. Expected design life: you have to do calculations for the expected life of the bearing in millions of cycles (L10)

SKF.com offers a selection wizard. You can refer to that.

Best of luck

Hello,

If you have a machine from Stratasys Dimension Elite also FDM system then the problem with the temperature does not exist.

Almost all home FDM systems have this problem, depending on who is producer of.

So it must be that explores that temperatures are optimal.

Best regards,

If you want, you can read this paper: On the influence of cutting speed limitation on the accuracy of wire-EDM corner-cutting. J Mater Process Technol

J.A. Sanchez · J. L. Rodil · A. Herrero · L. N. Lopez de lacalle · A. Lamikiz, here en RG.

Regards.

The thickness of the tank wil keep on increasing based on the pressure difference between the outside and inside of the tank. If the height is also large and is to be filled with liquid, the pressure difference will be quite a lot, assuming it is open tank and outside as well as inside is at atmospheric pressure.

Try the lacquer made of polystyrene dissolved in acetone. Cheap as dirt and white.

I am of the opinion that they should check their sparking conditions again. Basically black layers or carbon deposits occur only if the arc erosion is primary. In special cases they can be eliminated by an improved flushing the still. It is even better, however, to verify the process parameters.

You can assume that they reach 95% of the discharge machining, which runs in the optimum parameter range, no deposits of this type. Do you want to check but also "unacceptable" parameter ranges, then you need to take advantage of the already made proposals to remove the black layer.

Best regards

Hans-Peter Schulze

Great! thanks!

Dear Mr. Nobre, 

Thanks for  the links that you shared but I was looking for  technical papers which explain manufacturing method step by step. Anyway I have found beneficial sources which are helpful about skinning and wrapping of  carbon fibers. Thanks again for the links. 

Regards. 

The main structure of Philae is made of carbon fibre and carbon fibre with aluminum honeycomb.

Obviously, there is a huge number of other materials used for the subsystems.

Additional structural elements and mechanisms are to a large extent made of aluminum, titanium and certain, space qualified, plastic materials.

Do you have any specific interest in a particular material? 

Thanks for all the replies.

Regards,

Many thanks Mr Mark.

Really appreciated.

It is easy. Run a DSC test and determine the heat of melting H_f (j/g) and then use the hereunder formula:

Degree of crystalinity =  (H_f (j/g)/(H₀* w))*100

H₀ is enthalpy of fusion of 100% crystalline PA 9- You may find it by searching on net

w is percent of PA 9 in the composite

The type of the iron ore is very important. I mean that in the case the raw ore is BIF, it includes high amount of silica (Up to 20%) but ironstone, for example,  contains less amounts of silica

The subject is dealt with in the book by Norman Bailey and myself entitled,

The Metallurgy of Basic Weld Metal"

Glyn Evans.

2 m diameter is large. Can it be placed entirely in the machine (is the machine large enough?) or is that why they need the rotary table?

If fit fits in the machine:

1. Are all holes angles to the same direction? If so, you can calibrate the probe in that direction/angle in order to measure a circle.

2. If the holes angles are all in different directions, you´ll be measuring ellipses. You´ll need to know the diameter of the hole and find a probe with a diameter that can touch the hole without coliding with the 'shaft' of the probe, as the holes are in a 10 degree angle. Look for a large probe diameter with a small shaft diameter. Probably you won´t be able to measure the hole in all extension. Take into account the tolerance of the measurement - it won´t be a perfect measurement, but the center of various ellipses of the same hole can give you a good idea of the angular position of the hole and maybe if the 10 degree angle is in the correct direction.

As per my knowledge, Diamond turned surfaces do not require any post processing. Because it can produce nano and Angstrom level surface finish. if you feel any post polishing, I think you can go for MRF (Magnetorheological finishing).

You know another methods, another machines to make blockers?

The fundamental (Gaussian) mode can be focused to the smallest spot. For any higher mode the spot is bigger M^2 times, where M^2 is beam quality factor.

Theoretical reasons are beam propagation equations derived from wave equation or from Maxwell equations. The beam is characterised by invariant = (minimal spot)*(divergence angle) =  wavelength*M^2/pi

Low power lasers may work with single Gaussian mode with M^2 = 1. It is useful in many of applications. However, in powerful industrial lasers usually higher modes are also generated and minimal achievable spots are bigger. 

Search "beam quality factor" over the net or see for example:

Hi Sir, 

You have to do heat analysis on the software and push in your material and simulate the model later on.

All the best,

kawin