Talk:Die casting/GA1

GA Review

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Reviewer: Pyrotec (talk) 22:05, 7 October 2010 (UTC)

I will review. Pyrotec (talk) 22:05, 7 October 2010 (UTC)

Initial comments

I'm sorry for the delay, I had a short wikibreak over the weekend.

I've now had a quick read though of the article. Certainly the article appears to be of GA-standard, I think it should get through GA this time round, but I consider that it needs a bit of work in some sections.

• I normally leave the WP:Lead until last, and I intend to do so this time. However, I will note here, that the Lead will need some work done on it to get through GA.
• The Process section, as it stands, is generally OK in that it describes four steps. There is, however, at least one probably two stages that precede these four steps. Its not just a case of shoving metal in a mould, etc, the mold/die comes first. It has to be designed and made; and this appears to be absent from the article.

Pyrotec (talk) 21:52, 11 October 2010 (UTC)

I will now start to review the article in more detail. At this stage I tend mostly to highlight any "problems", so if I don't say very much about any particular section or subsection that probably means that its OK; but I will be producing an overall summary at the end.

• Article as a whole -

• Y Pyrotec (talk) 09:04, 1 November 2010 (UTC) - I suggest that the material in this article might need to be presented under a slightly different arrangement of section headings. My comments (below) on the Process section are that I consider the process has "blured over" the mould/die design and building stage(s). There are undefined/discussed technical terms in this section that appeared to involve decisions of mould/die design. There are also discussions of mould/die design and moulded-in inserts that appear in the Equipment section. This section also seems to ignore the stage(s) of mould/die design, but then goes onto discuss technical terms and decisions that must have been made during this (missing) mould/die design stage. Some of these technical terms are unexplained.

Added a "dies" section. Wizard191 (talk) 19:51, 31 October 2010 (UTC)

• Y Pyrotec (talk) 09:04, 1 November 2010 (UTC) - The 'Pore-free casting process has a through-away remark "These castings can still be heat treated and welded" which possibly suggests that items made using the other types of die casting process might also have these properties. Let's have a clear statement on heat treatment and weldability.

Corrected the advantages and disadvantages section to explain that standard die castings can't be heat treated or welded. Copyedited the Pore-free casting process section. Wizard191 (talk) 00:59, 20 October 2010 (UTC)

• History -

• Generally OK.
• Y Pyrotec (talk) - It has one citation which is a "raw" web site address. The citation should be properly cited, giving web name, publisher url, date of access, etc. The {{cite web}} may be used, but its not mandatory. The citation however should be correctly provided.

Formatted. Wizard191 (talk) 16:57, 15 October 2010 (UTC)

• Process (first part, no subsection title) -

• Y Pyrotec (talk) 17:53, 30 October 2010 (UTC) - This states that there are four steps, but its not clear what they are, and there may be five: e.g. Lub and close; fill; hold and cool; open; remove scrap. This should be clarified and the four (?) main stages clearly identified.

I have clarified this. Note that I added a red link, which I plan on making into a real article in the future (though not before you finish reviewing this article). Wizard191 (talk) 17:32, 20 October 2010 (UTC)

• Y Pyrotec (talk) 17:53, 30 October 2010 (UTC) - The first stage (this one is probably obvious) is described as "spray with lubricant" and close the mould. Can any lubricant be used, or must be it specially selected? If it has to be specially selected, than this description becomes inadequate.

I have added a lubrication section. I may move it to a different location depending on what the new layout looks like in the near future. Wizard191 (talk) 18:22, 20 October 2010 (UTC)

• Y Pyrotec (talk) 09:04, 1 November 2010 (UTC) - There are numerous technical terms that aren't discussed, or merely relegated to brackets (braces, if you prefer). They include: shot/castings, gate, runners, sprues and flash (the last two are however wikilinked). I suspect that they should be discussed in the section (see below) that seems to be missing from this article (some also appear again in Equipment).
• Y Pyrotec (talk) 09:04, 1 November 2010 (UTC) - There are, however, at least one probably two stages that precede these four steps. Its not just a case of shoving metal in a mould/die, etc, the mold/die comes first. It has to be designed and made and this appears to be absent from the article; however, some further discussion of dies appears in the Equipment section.

Added a "dies" section. Wizard191 (talk) 19:51, 31 October 2010 (UTC)

• Y Pyrotec (talk) - Ref 5 is provided as a "raw" web site address. The citation should be properly cited, giving web name, publisher url, date of access, etc. The {{cite web}} may be used, but its not mandatory. The citation however should be correctly provided.

Formatted. Wizard191 (talk) 16:57, 15 October 2010 (UTC)

• Y Pyrotec (talk) 09:04, 1 November 2010 (UTC) - The second paragraph has a technical term "discontinuity" which is only named, but not described. It also seem to be mainly related to this missing section on mould/die design.

Added link. Wizard191 (talk) 01:23, 20 October 2010 (UTC)

• The final paragraph is just floating there. I probably understand what it aims to say: but these operations, I assume, are carried out on the finished or semi finished article, e.g. after scrap removal. If so, is this not a fifth or sixth stage in the process?

• Pore-free casting process -

• Y Pyrotec (talk) 09:51, 1 November 2010 (UTC) - Injection is a term used both for the metal and the oxygen. Pressure (pressure range) is stated for the metal, but not for oxygen (perhaps its only a "purge", but that would be an improvement).

I added "to purge any air from the mold cavity" to clarify. Wizard191 (talk) 01:02, 20 October 2010 (UTC)

....to be continued. Pyrotec (talk) 09:43, 15 October 2010 (UTC)

• Equipment -

• Y Pyrotec (talk) - I assume in "The gas or oil powered piston then forces this metal out of the gooseneck into the die", gas or oil refers to pneumatic or hydraulic pressure?

Clarified. Wizard191 (talk) 18:23, 15 October 2010 (UTC)

• Y Pyrotec (talk) 19:48, 15 October 2010 (UTC) - It states in regard to Cold-chamber machines: "This machine works by melting the material, first, in a separate furnace". I though the point was that the machine did not melt the material, it was melted elsewhere in a separate furnace. This and the following sentence aught to read something like "The material is melted in a separate furnace. A precise amount of molten metal is transported to the cold-chamber machine where it is fed into an unheated shot chamber (or injection cylinder)."

Corrected. Wizard191 (talk) 19:35, 15 October 2010 (UTC)

• Y Pyrotec (talk) 15:56, 31 October 2010 (UTC) - This section starts by discussing hot-chamber machines and cold-chamber machines and then there are three paragraphs on dies, die design and sand cores. Its not made clear how dies relate to hot-chamber machines and cold-chamber machines. Since these paragraphs follow straight after cold-chamber machines, it could be assumed that this is a continuation of the cold-chamber machines - which I suspect it is not. They are something to do with mould/die design and construction, which I think aught to have its own section; but I assume that they could be used (interchangeably within limits?) in both hot and cold chamber machines.
• Y Pyrotec (talk) 09:51, 1 November 2010 (UTC) - I think sand cores is certainly a mould/die design question, even if it does impact on equipment in respect of core insertion and core removal.

I completely fleshed this out in the "dies" section. Wizard191 (talk) 19:51, 31 October 2010 (UTC)

• Y Pyrotec (talk) 16:44, 16 October 2010 (UTC) - The final paragraph before the table refers to wikilinked technical terms such as H13, 440B. These are US technical standards. Their scope aught to be made a bit more generic, such as: "Dies for zinc are often made of tool steel (such as AISI-SAE grade H13) and only hardened to Rockwell scale 29-34 HRC.[11] Cores are either made of tool steel (such as H13) or Stainless steel (such as SAE steel grade 440B), so that the wearing parts can be selectively nitrided for hardness, leaving the exposed part soft to resist heat checking.[11]".

Generalized. Wizard191 (talk) 20:35, 15 October 2010 (UTC)

• Y Pyrotec (talk) 09:51, 1 November 2010 (UTC) - It also includes the technical term heat checking which is discussed after the table in a bullet-pointed list (two items) on die failure mode.

I'm not really sure how to get around this, because it doesn't make sense to discuss less common failure modes before the most common type. Wizard191 (talk) 01:28, 20 October 2010 (UTC)

• Citation 11 seems to be strangely quoted. Its quoted as: prepared under the direction of the ASM International Handbook Committee; chairman, D.M. Stefanescu. (1988), ASM Handbook, 15, ASM International, p. 789, ISBN 0871700212, http://books.google.com/?id=KCUjfz-ILSEC . However, following the web link: its title appears to be "Materials selection and design", its ASM Handbook Volume 20, and its editor George E. Dieter. Either the wrong book is being cited, or the wrong web link has been given. Citation 12 appears to be a volume in the similar series but from a difference society, so I would have expected citation 11 to be similar in style to citation 12.

Fixed. Wizard191 (talk) 01:49, 20 October 2010 (UTC)

• Y Pyrotec (talk) 15:56, 31 October 2010 (UTC) - To clarify, this section could be split into subsections on hot-chamber machines, cold-chamber machines and dies and cores; or (as mentioned above) could the mould/dies and cores be moved into a separate section on dies?

• Advantages and disadvantages & Die casting materials -

• Probably OK.

....to be continued. Pyrotec (talk) 11:05, 15 October 2010 (UTC)

• WP:Lead -

....to be continued, as review is currently On Hold for the points above to be addressed. Pyrotec (talk) 19:19, 15 October 2010 (UTC)

Progress report

The article has been much improved; and I regard the main body of the article to be generally GA-compliant (but I'm still considering Advantages/Disadvantages), but I may tweak it a bit as I further review it. The WP:Lead is the section that needs most attention. The lead is intended to both introduce the article (which is does quite well) and to summarise the main points (which could go with some attention).

....to be continued. Pyrotec (talk) 16:14, 31 October 2010 (UTC)

I'm still working on the whole thing in general. Hopefully I will finish her off today. Wizard191 (talk) 19:38, 31 October 2010 (UTC)

Alright, I think I've tried to fix all of your points. If I missed something, let me know and I'll try and rectify it. Wizard191 (talk) 21:20, 31 October 2010 (UTC)

I've added a couple of points; but we may be able to close this review off today. Its mostly completed. Pyrotec (talk)

• Cast metals -

• The AA 300-series alloy designations needs to be be clarified. I suspect that that they are standards for aluminium alloys produced by a US standards organisation. Looking in a UK-orientated reference book, I see references to BS 1490: 1988 (and alloys such as LM2, LM4, LM6, LM20) and cross references to similar ISO 3522 alloys.

If you have a ref for these, feel free to add them. Wizard191 (talk) 17:47, 1 November 2010 (UTC)

So far I added a link to The Aluminum Association, as they appear to be responsible for the AA standards. Pyrotec (talk) 21:16, 1 November 2010 (UTC)

• Process -

• Quality, as in QC / GA (Control / Assurance) seems to be absent. I'm thinking that it could possibly appear here. You added a "piped" link to Casting defects which could be referenced again, e.g. by a {{Main}} or a {{Seealso}}. Quality I suspect depends on the product, high for engine casting and possibly high-price limited-issue scale models for collectors, but low for other applications.

Added inspection section. Wizard191 (talk) 17:42, 1 November 2010 (UTC)

• Advantages and disadvantages -

• Advantages, probably OK.
• Disadvantages, rather thin in places, i.e. "High initial cost." could be expanded to "High initial costs, due to the need to design and manufacture dies." I assume that this would also involve delays in start up from scratch.

I fleshed this out a little more. Wizard191 (talk) 18:14, 1 November 2010 (UTC)

• What about alteratives: machine the part out of a solid block: machine the part out of a semi-finished rough casting (e.g. I can buy a rough casting for a lathe chuck backplate).

I'm not sure what you mean by this exact point. A general overview of various metalworking processes are given at metalworking, however its hard to compare x process vs. y process due to the number of variables involved. Everyday at my job I have to make a judgment call when I design to assign a manufacturing process(es) to it, and its done on a piece by piece basis; and if its too close to call then I have to model up both forms and actually give it to the vendors to get exact numbers for each process. So to make a long answer short, I don't think this point can be included. Wizard191 (talk) 17:46, 1 November 2010 (UTC)

Overall review

GA review – see WP:WIAGA for criteria

1. Is it reasonably well written?

   A. Prose quality:

   B. MoS compliance for lead, layout, words to watch, fiction, and lists:

2. Is it factually accurate and verifiable?

   A. References to sources:

   Well referenced

   B. Citation of reliable sources where necessary:

   Well referenced

   C. No original research:

3. Is it broad in its coverage?

   A. Major aspects:

   B. Focused:

4. Is it neutral?

   Fair representation without bias:

5. Is it stable?

   No edit wars, etc:

6. Does it contain images to illustrate the topic?

   A. Images are copyright tagged, and non-free images have fair use rationales:

   B. Images are provided where possible and appropriate, with suitable captions:

7. Overall:

   Pass or Fail:

   Overall a good article. Whilst the main body of the article appears to be fully compliant with WP:WIAGA, the WP:Lead was rather weak. I've tried to improve the lead and remove some of the bias, but some futher work is need to bring it up to the same standard as the rest of the article. Pyrotec (talk) 19:21, 2 November 2010 (UTC)

I'm awarding this article GA-status, as the article has been much improved during this review. The WP:Lead however could do with further work: it should provide both an introduction to the article and a sumary of the main points. I've made some changes as the lead did not reflect all the points made in the body of the article; and was some biased in respect of costs. Pyrotec (talk) 19:30, 2 November 2010 (UTC)

Thanks for your hard work and the GA! Your input definitely helped to make this article much better than it was. Maybe someone else can come along and help clean-up the lead, because honestly that's not one of my strong points. Cheers! Wizard191 (talk) 19:51, 2 November 2010 (UTC)

I'm happy to work on the lead, but that will not be until after I've finished two more reviews. Pyrotec (talk) 19:54, 2 November 2010 (UTC)