(1. 北京交通大學(xué) 機(jī)械與電子控制工程學(xué)院，北京 100044；
2. 河北科技大學(xué) 材料科學(xué)與工程學(xué)院， 石家莊 050054)
摘 要: 通過(guò)對(duì)半固態(tài)合金流變充型過(guò)程的物理分析， 結(jié)合半固態(tài)合金包含圣維南體和假塑性體的流變特性， 根據(jù)充型驅(qū)動(dòng)力大于或等于充型阻力， 阻流通道內(nèi)不可流動(dòng)層厚度小于阻流截面最小厚度的1/2這兩個(gè)充型臨界條件， 運(yùn)用不可壓縮粘性流體流動(dòng)理論， 建立半固態(tài)合金充滿型腔獲得完整零件的兩個(gè)臨界條件的數(shù)學(xué)表達(dá)式。 為了驗(yàn)證其準(zhǔn)確性， 對(duì)鉤舌、 軸箱體零件進(jìn)行了流變成形實(shí)驗(yàn)， 實(shí)驗(yàn)結(jié)果證實(shí)該臨界條件數(shù)學(xué)表達(dá)式的正確性。 該式包含設(shè)備參數(shù)、 工藝參數(shù)、 材料參數(shù)和模具參數(shù)， 可用來(lái)指導(dǎo)半固態(tài)流變成形工藝設(shè)計(jì)、 設(shè)備選型， 并能進(jìn)行缺陷預(yù)測(cè)和充型過(guò)程控制。
關(guān)鍵字: 半固態(tài)合金； 充型阻力； 阻流通道； 臨界條件
LI Li-xin2, LI Zeng-min2, LI Xun2
（1. School of Mechanical and Electronic Control Engineering,
Beijing Jiaotong University, Beijing 100044, China;
2. School of Materials Science and Engineering, Hebei University of
Science and Technology, Shijiazhuang 050054, China）
Abstract: By the physical analysis about the rheological filling process of semi-solid alloy, based on the rheological characteristic of semi-solid alloy which includes saint venant body and pseudoplastic, according to the two filling critical conditions that the driving force of mold filling is greater than mold filling resistance and the thickness of non-flowing layer in the channel of resistance to flow is thinner than a half of the minimum of the channel section, managing the flow theory about incompressible viscous fluid, the mathematic representations of the two critical conditions that the cavity can be filled with semi-solid alloy to obtain the perfect casting were deduced. In order to demonstrate the accuracy of the criterion condition, the rheoforming experiment of the hook-head casting and axle box boby casting is carried out. The result of the experiment shows the accuracy of the criterion condition. The mathematic representation includes the equipment parameters, processing parameters, material parameters and mould parameters. It can be used to instruct the technological design and equipment selection about the semi-solid rheoforming. Moreover, it also can be used to forecast flaw and control filling process.
Key words: semi-solid alloy; mold filling resistance; channel of resistance to flow; critical condition
