(燕山大學(xué) 材料工程學(xué)院， 秦皇島 066004)
摘 要: 研究了添加Mn、 Ni對ZA27合金組織和性能的影響。 結(jié)果表明： 適量Mn、 Ni的添加在不明顯降低室溫強度的條件下， 顯著提高了合金的高溫性能； 同時添加質(zhì)量分數(shù)為0.5%Mn和0.5%Ni使鑄態(tài)ZA27合金非平衡網(wǎng)狀三相共晶中出現(xiàn)大量富鎳相粒子， 在250 ℃、 拉伸機橫梁移動速率為100 mm/min條件下的瞬時抗拉強度27.2 MPa比未加Mn、 Ni的合金提高46%； Mn、 Ni的添加使280 ℃、 初始應(yīng)變速率6.67×10-2 s-1條件下的超塑性拉伸的穩(wěn)態(tài)流變應(yīng)力由12.4 MPa提高到24.6 MPa， 比未加Mn、 Ni的合金提高98%。 掃描電鏡觀察與X射線能譜分析表明， Mn、 Ni顯著提高超塑性拉伸的穩(wěn)態(tài)流變應(yīng)力的主要原因與“離位析出”富含Cu、 Ni、 Mn的粒子有關(guān)。
關(guān)鍵字: ZA27合金； Mn-Ni合金化； 超塑性； 力學(xué)性能
microstructures and mechanical properties
of ZA27 alloy
（College of Materials Science and Technology,
Yanshan University, Qinhuangdao 066004, China）
Abstract: The effect of Mn and Ni additive on the microstructure and mechanical property of ZA27 alloy was studied. The appropriate additive of Mn and Ni can remarkably raise the strength in high-temperature, under condition that room temperature strength only decreases slightly. When the additives of Mn and Ni are all 0.5% in the mean time, great quantities of Ni-enriched particles appear in reticulate unbalanced three-phase eutectic of the as-cast ZA27 alloy, which made the instantaneous tensile strength of the alloy lift to 27.2 MPa that is 46% higher than that of not undergone Mn-Ni alloying under the condition of 250 ℃ and 100 mm/min. In the super plastic tensile testing with 280 ℃, the initial strain speed of 6.67×10-2 s-1, Mn-Ni additive made the stable flowing stress rise from 12.4 MPa to 24.6 MPa that is 98% higher than that of without Mn-Ni additives. Concluded from the results of TEM and DES analyses, the cardinal reason of the remarkable enhancement of stable flowing stress in super plastic tensile testing is directly related to the precipitation of particles enriched Cu, Ni and Mn.
Key words: ZA27 alloy; Mn-Ni alloying; super plasticity; mechanical property
