鑄造趨勢

“十五”期間，鑄(zhu)造(zao)行業(ye)主要(yao)經濟指標的(de)(de)(de)年均增長(chang)都(dou)在30%以上(shang)，高(gao)于(yu)機床工(gong)具全行業(ye)平(ping)(ping)均增長(chang)水(shui)(shui)平(ping)(ping)，特別是利(li)潤增長(chang)更快，年均利(li)潤增長(chang)高(gao)達46%，同時也保持(chi)較高(gao)的(de)(de)(de)市場銷售水(shui)(shui)平(ping)(ping)。另外，樹脂砂(sha)鑄(zhu)造(zao)成套設(she)備(bei)，基(ji)本可以滿足需求，改(gai)變了過(guo)去主要(yao)依賴進口的(de)(de)(de)局(ju)面；已經能夠生(sheng)(sheng)產出較高(gao)水(shui)(shui)平(ping)(ping)的(de)(de)(de)鑄(zhu)造(zao)自(zi)(zi)動(dong)(dong)(dong)(dong)(dong)生(sheng)(sheng)產線(xian)，達到可部分(fen)替(ti)代進口的(de)(de)(de)水(shui)(shui)平(ping)(ping)，部分(fen)的(de)(de)(de)解決了轎車發動(dong)(dong)(dong)(dong)(dong)機缸(gang)體、缸(gang)蓋等鑄(zhu)件毛坯也要(yao)進口的(de)(de)(de)情況；高(gao)水(shui)(shui)平(ping)(ping)自(zi)(zi)動(dong)(dong)(dong)(dong)(dong)制芯(xin)機、自(zi)(zi)動(dong)(dong)(dong)(dong)(dong)鑄(zhu)件清(qing)理機、自(zi)(zi)動(dong)(dong)(dong)(dong)(dong)砂(sha)處理機、大型自(zi)(zi)動(dong)(dong)(dong)(dong)(dong)壓鑄(zhu)機以及精(jing)密鑄(zhu)造(zao)設(she)備(bei)等鑄(zhu)造(zao)機械，國內(nei)基(ji)本上(shang)都(dou)能生(sheng)(sheng)產制造(zao)。應當說“十五”期間鑄(zhu)造(zao)機械行業(ye)的(de)(de)(de)產品水(shui)(shui)平(ping)(ping)有了很大提高(gao)，為中國鑄(zhu)造(zao)機械行業(ye)今后的(de)(de)(de)進一(yi)步發展打下(xia)良(liang)好(hao)基(ji)礎。

砂(sha)(sha)(sha)(sha)(sha)(sha)(sha)(sha)型(xing)(xing)(xing)(xing)(xing)(xing)鑄(zhu)(zhu)(zhu)(zhu)(zhu)造(zao)(zao)(zao)(zao)(zao)是一(yi)種以砂(sha)(sha)(sha)(sha)(sha)(sha)(sha)(sha)作(zuo)為(wei)主(zhu)要造(zao)(zao)(zao)(zao)(zao)型(xing)(xing)(xing)(xing)(xing)(xing)材料，制作(zuo)鑄(zhu)(zhu)(zhu)(zhu)(zhu)型(xing)(xing)(xing)(xing)(xing)(xing)的(de)(de)傳統鑄(zhu)(zhu)(zhu)(zhu)(zhu)造(zao)(zao)(zao)(zao)(zao)工藝。砂(sha)(sha)(sha)(sha)(sha)(sha)(sha)(sha)型(xing)(xing)(xing)(xing)(xing)(xing)一(yi)般采用(yong)重力鑄(zhu)(zhu)(zhu)(zhu)(zhu)造(zao)(zao)(zao)(zao)(zao)，有特殊(shu)要求(qiu)時也(ye)可采用(yong)低壓鑄(zhu)(zhu)(zhu)(zhu)(zhu)造(zao)(zao)(zao)(zao)(zao)、離(li)心鑄(zhu)(zhu)(zhu)(zhu)(zhu)造(zao)(zao)(zao)(zao)(zao)等工藝。砂(sha)(sha)(sha)(sha)(sha)(sha)(sha)(sha)型(xing)(xing)(xing)(xing)(xing)(xing)鑄(zhu)(zhu)(zhu)(zhu)(zhu)造(zao)(zao)(zao)(zao)(zao)的(de)(de)適應性很廣，小件(jian)(jian)(jian)、大件(jian)(jian)(jian)，簡單(dan)件(jian)(jian)(jian)、復雜件(jian)(jian)(jian)，單(dan)件(jian)(jian)(jian)、大批(pi)量都可采用(yong)。砂(sha)(sha)(sha)(sha)(sha)(sha)(sha)(sha)型(xing)(xing)(xing)(xing)(xing)(xing)鑄(zhu)(zhu)(zhu)(zhu)(zhu)造(zao)(zao)(zao)(zao)(zao)用(yong)的(de)(de)模(mo)(mo)具，以前多(duo)(duo)用(yong)木(mu)材制作(zuo)，通稱木(mu)模(mo)(mo)。旭東(dong)精密鑄(zhu)(zhu)(zhu)(zhu)(zhu)件(jian)(jian)(jian)廠(chang)為(wei)改變木(mu)模(mo)(mo)易變形、易損壞等弊病，除單(dan)件(jian)(jian)(jian)生(sheng)產(chan)的(de)(de)砂(sha)(sha)(sha)(sha)(sha)(sha)(sha)(sha)型(xing)(xing)(xing)(xing)(xing)(xing)鑄(zhu)(zhu)(zhu)(zhu)(zhu)件(jian)(jian)(jian)外(wai)，全部改為(wei)尺寸精度(du)較(jiao)(jiao)高(gao)，并且使用(yong)壽命較(jiao)(jiao)長的(de)(de)鋁(lv)合金模(mo)(mo)具或(huo)樹脂模(mo)(mo)具。雖然價(jia)格(ge)有所提高(gao)，但仍比金屬型(xing)(xing)(xing)(xing)(xing)(xing)鑄(zhu)(zhu)(zhu)(zhu)(zhu)造(zao)(zao)(zao)(zao)(zao)用(yong)的(de)(de)模(mo)(mo)具便宜得(de)多(duo)(duo)，在(zai)小批(pi)量及大件(jian)(jian)(jian)生(sheng)產(chan)中，價(jia)格(ge)i優(you)勢尤為(wei)突(tu)出。此外(wai)，砂(sha)(sha)(sha)(sha)(sha)(sha)(sha)(sha)型(xing)(xing)(xing)(xing)(xing)(xing)比金屬型(xing)(xing)(xing)(xing)(xing)(xing)耐火度(du)更高(gao)，因(yin)而如(ru)銅(tong)合金和黑色金屬等熔點較(jiao)(jiao)高(gao)的(de)(de)材料也(ye)多(duo)(duo)采用(yong)這(zhe)種工藝。但是，砂(sha)(sha)(sha)(sha)(sha)(sha)(sha)(sha)型(xing)(xing)(xing)(xing)(xing)(xing)鑄(zhu)(zhu)(zhu)(zhu)(zhu)造(zao)(zao)(zao)(zao)(zao)也(ye)有一(yi)些不(bu)足之處：因(yin)為(wei)每(mei)個砂(sha)(sha)(sha)(sha)(sha)(sha)(sha)(sha)質鑄(zhu)(zhu)(zhu)(zhu)(zhu)型(xing)(xing)(xing)(xing)(xing)(xing)只(zhi)能(neng)澆注(zhu)一(yi)次，獲得(de)鑄(zhu)(zhu)(zhu)(zhu)(zhu)件(jian)(jian)(jian)后(hou)(hou)鑄(zhu)(zhu)(zhu)(zhu)(zhu)型(xing)(xing)(xing)(xing)(xing)(xing)即(ji)損壞，必(bi)須(xu)重新造(zao)(zao)(zao)(zao)(zao)型(xing)(xing)(xing)(xing)(xing)(xing)，所以砂(sha)(sha)(sha)(sha)(sha)(sha)(sha)(sha)型(xing)(xing)(xing)(xing)(xing)(xing)鑄(zhu)(zhu)(zhu)(zhu)(zhu)造(zao)(zao)(zao)(zao)(zao)的(de)(de)生(sheng)產(chan)效率(lv)較(jiao)(jiao)低；又(you)因(yin)為(wei)砂(sha)(sha)(sha)(sha)(sha)(sha)(sha)(sha)的(de)(de)整體(ti)性質軟而多(duo)(duo)孔，所以砂(sha)(sha)(sha)(sha)(sha)(sha)(sha)(sha)型(xing)(xing)(xing)(xing)(xing)(xing)鑄(zhu)(zhu)(zhu)(zhu)(zhu)造(zao)(zao)(zao)(zao)(zao)的(de)(de)鑄(zhu)(zhu)(zhu)(zhu)(zhu)件(jian)(jian)(jian)尺寸精度(du)較(jiao)(jiao)低，重力鑄(zhu)(zhu)(zhu)(zhu)(zhu)造(zao)(zao)(zao)(zao)(zao)公(gong)司，表(biao)面也(ye)較(jiao)(jiao)粗糙(cao)。不(bu)過，精密鑄(zhu)(zhu)(zhu)(zhu)(zhu)件(jian)(jian)(jian)廠(chang)集多(duo)(duo)年的(de)(de)技術積累，已大大改善了砂(sha)(sha)(sha)(sha)(sha)(sha)(sha)(sha)型(xing)(xing)(xing)(xing)(xing)(xing)鑄(zhu)(zhu)(zhu)(zhu)(zhu)件(jian)(jian)(jian)的(de)(de)表(biao)面狀況，其拋丸(wan)后(hou)(hou)的(de)(de)效果可與金屬型(xing)(xing)(xing)(xing)(xing)(xing)鑄(zhu)(zhu)(zhu)(zhu)(zhu)件(jian)(jian)(jian)媲美。

熔模鑄造(zao)的鑄型可分為實體型和多層型殼兩種(zhong)

將(jiang)模(mo)組(zu)浸涂耐火涂料后(hou)，撒上(shang)料狀(zhuang)耐火材(cai)料，再(zai)經干燥、硬化(hua)，如此反(fan)復多(duo)(duo)次，使耐火涂掛層達到(dao)需要的厚(hou)度為止，這樣便在模(mo)組(zu)上(shang)形(xing)成了多(duo)(duo)層型殼，通常將(jiang)近(jin)其(qi)停放一段時間，使其(qi)充分硬化(hua)，然(ran)后(hou)熔失模(mo)組(zu)，重力鑄(zhu)造價(jia)格(ge)，便得到(dao)多(duo)(duo)層型殼。

多層殼(ke)有的(de)需(xu)要裝箱填砂；有的(de)則(ze)不需(xu)要，經(jing)過焙燒后(hou)就可直接進(jin)行澆注。

在熔失熔模(mo)時(shi)，重力鑄(zhu)(zhu)造哪家好，型(xing)殼(ke)會受(shou)到體積正(zheng)在增大的(de)熔融模(mo)料(liao)的(de)壓(ya)力；在焙燒(shao)和(he)澆注(zhu)時(shi)，型(xing)殼(ke)各部分(fen)會產(chan)生相互牽制而又不均的(de)膨脹的(de)收(shou)縮，重力鑄(zhu)(zhu)造，因此，金屬還可能與(yu)(yu)型(xing)殼(ke)材料(liao)發生高溫化學反應。所以(yi)對(dui)型(xing)殼(ke)便有一(yi)定的(de)性(xing)(xing)能要求(qiu)，如(ru)小(xiao)的(de)膨脹率(lv)和(he)收(shou)縮率(lv)；高的(de)機械強度、抗熱震性(xing)(xing)、耐火(huo)度和(he)高溫下的(de)化學穩定性(xing)(xing)；型(xing)殼(ke)還應有一(yi)定的(de)透氣性(xing)(xing)，以(yi)便澆注(zhu)時(shi)型(xing)殼(ke)內的(de)氣體能順(shun)利外逸。這些都與(yu)(yu)制造型(xing)殼(ke)時(shi)所采(cai)用(yong)的(de)耐火(huo)材料(liao)、粘(zhan)結劑以(yi)及工藝有關(guan)。