金(jin)(jin)屬(shu)塑(su)(su)性成(cheng)形(xing)(xing)(xing)(xing) 利用(yong)金(jin)(jin)屬(shu)材料的(de)塑(su)(su)性性質加(jia)工,使之具有所需形(xing)(xing)(xing)(xing)狀的(de)過(guo)程(cheng)(cheng)。金(jin)(jin)屬(shu)材料經成(cheng)形(xing)(xing)(xing)(xing)過(guo)程(cheng)(cheng)后,其組織、性能獲(huo)得(de)改善和提(ti)高。凡受交變載荷作(zuo)用(yong)或受力條件(jian)惡劣的(de)構件(jian),一般(ban)都要通過(guo)塑(su)(su)性成(cheng)形(xing)(xing)(xing)(xing)過(guo)程(cheng)(cheng),才(cai)能達(da)(da)到使用(yong)要求。塑(su)(su)性成(cheng)形(xing)(xing)(xing)(xing)是無(wu)切屑成(cheng)形(xing)(xing)(xing)(xing)方法,因而能使工件(jian)獲(huo)得(de)良好(hao)的(de)流線形(xing)(xing)(xing)(xing)狀及合理的(de)材料利用(yong)率。用(yong)塑(su)(su)性成(cheng)形(xing)(xing)(xing)(xing)方法可使工件(jian)尺寸達(da)(da)到較(jiao)高精(jing)度(du),具有很(hen)高的(de)生產(chan)效(xiao)率。
塑性(xing)(xing)成(cheng)形(xing)(xing)分冷(leng)成(cheng)形(xing)(xing)、溫成(cheng)形(xing)(xing)和(he)熱(re)成(cheng)形(xing)(xing)。溫成(cheng)形(xing)(xing)要考(kao)慮溫度對材料性(xing)(xing)質的(de)影響,熱(re)成(cheng)形(xing)(xing)還要考(kao)慮材料的(de)蠕變效應(ying)。金屬(shu)塑性(xing)(xing)成(cheng)形(xing)(xing)包括塊體成(cheng)形(xing)(xing)、板料成(cheng)形(xing)(xing)及(ji)軋制等(deng)(見塑性(xing)(xing)力(li)學)。各(ge)種塑性(xing)(xing)成(cheng)形(xing)(xing)都(dou)以金屬(shu)材料具有塑性(xing)(xing)性(xing)(xing)質為(wei)前提,都(dou)需要有外(wai)力(li)作用,都(dou)存在外(wai)摩擦的(de)影響,都(dou)遵循著共同(tong)的(de)金屬(shu)學和(he)塑性(xing)(xing)力(li)學規律。
應(ying)(ying)用塑(su)性(xing)力(li)(li)(li)學原理(li)研(yan)究(jiu)金屬(shu)成(cheng)(cheng)(cheng)形(xing)(xing)(xing)(xing)規律(lv)的(de)(de)方法(fa)(fa)(fa)(fa)稱金屬(shu)成(cheng)(cheng)(cheng)形(xing)(xing)(xing)(xing)的(de)(de)塑(su)性(xing)分析(xi)(xi),它的(de)(de)任務為:①研(yan)究(jiu)塑(su)性(xing)成(cheng)(cheng)(cheng)形(xing)(xing)(xing)(xing)過程中(zhong)有(you)(you)關(guan)力(li)(li)(li)學的(de)(de)各種解法(fa)(fa)(fa)(fa),以(yi)(yi)(yi)(yi)分析(xi)(xi)變(bian)(bian)(bian)形(xing)(xing)(xing)(xing)體內的(de)(de)應(ying)(ying)力(li)(li)(li)應(ying)(ying)變(bian)(bian)(bian)分布規律(lv),并確定變(bian)(bian)(bian)形(xing)(xing)(xing)(xing)力(li)(li)(li)和(he)(he)變(bian)(bian)(bian)形(xing)(xing)(xing)(xing)功,以(yi)(yi)(yi)(yi)便合理(li)地選(xuan)擇(ze)設備噸位及模(mo)具強度(du)。②研(yan)究(jiu)塑(su)性(xing)成(cheng)(cheng)(cheng)形(xing)(xing)(xing)(xing)過程中(zhong)構件應(ying)(ying)變(bian)(bian)(bian)和(he)(he)尺(chi)寸(cun)的(de)(de)變(bian)(bian)(bian)化規律(lv),選(xuan)擇(ze)合適的(de)(de)坯(pi)料和(he)(he)合理(li)的(de)(de)中(zhong)間毛坯(pi)形(xing)(xing)(xing)(xing)狀,以(yi)(yi)(yi)(yi)便**地達到構件所需(xu)的(de)(de)形(xing)(xing)(xing)(xing)狀。③研(yan)究(jiu)溫度(du)、應(ying)(ying)變(bian)(bian)(bian)率效應(ying)(ying)等加(jia)工條件對金屬(shu)塑(su)性(xing)加(jia)工抗力(li)(li)(li)的(de)(de)影響以(yi)(yi)(yi)(yi)及提高(gao)金屬(shu)韌性(xing)和(he)(he)降低抗力(li)(li)(li)的(de)(de)措施(shi),以(yi)(yi)(yi)(yi)獲得(de)具有(you)(you)良好性(xing)能(neng)的(de)(de)構件。金屬(shu)成(cheng)(cheng)(cheng)形(xing)(xing)(xing)(xing)的(de)(de)塑(su)性(xing)分析(xi)(xi)方法(fa)(fa)(fa)(fa)主要有(you)(you)主應(ying)(ying)力(li)(li)(li)法(fa)(fa)(fa)(fa)、滑移線法(fa)(fa)(fa)(fa)、上限法(fa)(fa)(fa)(fa)、有(you)(you)限元法(fa)(fa)(fa)(fa)等;而常(chang)用的(de)(de)實驗方法(fa)(fa)(fa)(fa)則有(you)(you)視塑(su)性(xing)法(fa)(fa)(fa)(fa)和(he)(he)密柵云紋(wen)法(fa)(fa)(fa)(fa)。